2026 ICD-10-CM Diagnosis Code D49.9Neoplasm of unspecified behavior of unspecified site

ICD-10-CM Codes›D50–D89›D49›D49

ICD-10-CM D49.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D49.9 is a billable ICD-10-CM diagnosis code for neoplasm of unspecified behavior of unspecified site. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 826 through 830, 843 through 845. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D49.9
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of unspecified behavior of unspecified site
Short Description
Neoplasm of unspecified behavior of unspecified site
Same as the full description in the CMS dataset.
Parent Code
D49
Neoplasms of unspecified behavior

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD49Neoplasms of unspecified behavior
CategoryD49Neoplasms of unspecified behavior
This CodeD49.9Neoplasm of unspecified behavior of unspecified site

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired ichthyosis
  • Acquired paraneoplastic ichthyosis
  • Acute febrile neutrophilic dermatosis
  • Acute febrile neutrophilic dermatosis due to neoplastic disease
  • Ampulla of Vater surgical margin, involved by tumor
  • Ampulla of Vater, distal pancreatic surgical margin, involved by tumor
  • Ampulla of Vater, posterior retroperitoneal pancreatic surface surgical margin, involved by tumor
  • Anal, deep radial surgical margin not involved by tumor
  • Anal, distal surgical margin not involved by tumor
  • Anal, proximal surgical margin not involved by tumor
  • Anaplasia absent
  • Annular tumor configuration
  • Anterior cord syndrome due to neoplasm
  • Anterior margin of tumor located anterior to equator of globe
  • Arthritis secondary to malignancy
  • Arthritis secondary to non-hematological malignancy
  • Brachial plexus neuropathy due to neoplasm
  • Brainstem encephalitis
  • Brown-Séquard syndrome due to neoplastic disease
  • Carcinoma-associated retinopathy
  • Central cord syndrome due to neoplasm
  • Cervical margins indeterminate for tumor involvement
  • Chorea due to paraneoplastic syndrome
  • Chronic tubulointerstitial nephritis due to neoplastic disease
  • Circumscribed tumor border
  • Comedo tumor pattern
  • Complete obstructing tumor
  • Coronary artery occlusion due to neoplastic disease
  • Cribriform tumor pattern
  • Cystic tumor configuration
  • Cystic, entirely encapsulated tumor
  • Cystic, partially encapsulated tumor
  • Deep radial periureteral soft tissue surgical margin, involved by tumor
  • Deep surgical margin involvement by tumor present
  • Dementia due to paraneoplastic encephalitis
  • Dermatomyositis with malignant disease
  • Diffuse anaplasia
  • Diffuse tumor configuration
  • Disorder of lumbosacral plexus due to neoplastic disease
  • Disorder of optic chiasm due to non-pituitary neoplasm
  • Distal pancreatic surgical margin, involved by tumor
  • Distal ureteral surgical margin, involved by tumor
  • Distance of tumor from anal verge unknown
  • Ectopic aldosterone secretion
  • Ectopic aldosterone-producing neoplasm
  • Endophytic tumor configuration
  • Esophageal surgical margin, involved by tumor
  • Esophagus, distal surgical margin, involved by tumor
  • Esophagus, proximal surgical margin, involved by tumor
  • Esophagus, radial surgical margin, involved by tumor
  • Estrogen receptor positive tumor
  • Excavated lesion of tumor
  • Exophytic tumor configuration
  • Expansile tumor configuration
  • Extent of tumor involvement not specified
  • Extrascleral tumor extension present
  • Familial neoplastic disease
  • Feminization due to tumor
  • Flat tumor
  • Flat tumor lesion
  • Focal anaplasia
  • Frond-like/villous tumor
  • Fungating tumor
  • Gerota's fascial surgical margin, involved by tumor
  • Glomerular disease due to neoplastic disease
  • Heart surgical margin, involved by tumor
  • Hemolytic anemia due to nonlymphoid neoplasm
  • Hemorrhagic tumor
  • Hormone receptor negative neoplasm
  • Hormone receptor positive tumor
  • Hypercortisolism due to nonpituitary tumor
  • Hypermelanosis due to ACTH/MSH-secreting tumor
  • Hypermelanosis due to neoplasia
  • Hypertrophic osteoarthropathy
  • Hypoglycemia due to neoplasm
  • Immunodeficiency secondary to neoplasm
  • Infiltrative tumor configuration, macroscopic
  • Intended postoperative presence of residual neoplasm following excision of neoplasm
  • Intraductal tumor configuration
  • Intraepithelial neoplasia due to human papillomavirus
  • Intratumoral/peritumoral lymphocytic response absent
  • Intratumoral/peritumoral lymphocytic response marked
  • Intratumoral/peritumoral lymphocytic response mild to moderate
  • Involvement of tumor by anaplasia indeterminate
  • Juvenile polymyositis
  • Juvenile polymyositis due to paraneoplastic syndrome
  • Kidney, ureteral surgical margin, involved by tumor
  • Large intestine surgical margin, involved by tumor
  • Large intestine, deep radial surgical margin not involved by tumor
  • Large intestine, deep radial surgical margin, involved by tumor
  • Large intestine, distal surgical margin not involved by tumor
  • Large intestine, distal surgical margin, involved by tumor
  • Large intestine, proximal surgical margin not involved by tumor
  • Large intestine, proximal surgical margin, involved by tumor
  • Large tumor
  • Left parametrial surgical margin, involved by tumor
  • Left ventricular outflow tract obstruction due to neoplasm
  • Limbic encephalitis
  • Local tumor spread
  • Localized tumor configuration
  • Lung surgical margin, involved by tumor
  • Lung, attached tissue surgical margin, involved by tumor
  • Lung, bronchial surgical margin, involved by tumor
  • Lung, parenchymal surgical margin, involved by tumor
  • Lung, vascular surgical margin, involved by tumor
  • Malignant neoplasm detection during interval between recommended screening examinations
  • Margin involvement indeterminate
  • Marked peritumoral lymphocytic response
  • Masquerade syndrome
  • Mass of thoracic vertebrae
  • Melanocytic neoplasm
  • Microcalcifications in tumor and non-neoplastic tissue present
  • Microcalcifications in tumor present
  • Micropapillary tumor pattern
  • Microvascular patterns present in tumor
  • Mild to moderate peritumoral lymphocytic response
  • Mixed endophytic and exophytic tumor configuration
  • Motor neuron disease due to neoplastic disease
  • Multifocal tumor
  • Multiple cranial nerve palsies in neoplastic disease
  • Myelopathy due to malignant neoplastic disease
  • Myelopathy due to neoplastic disease
  • Myopathy due to paraneoplastic syndrome
  • Necrotic tumor
  • Necrotizing cutaneous vasculitis
  • Neoplasm and/or hamartoma
  • Neoplasm following transplantation of bone marrow
  • Neoplasm following transplantation of liver
  • Neoplasm of bone of sacrum
  • Neoplasm of cervical vertebra
  • Neoplasm of left femur
  • Neoplasm of lumbar vertebra
  • Neoplasm of thoracic vertebra
  • Neoplastic complication of procedure
  • Neoplastic disease
  • Neoplastic masquerade syndrome
  • Neoplastic sequelae of disorders
  • Nerve root and plexus compressions in neoplastic disease
  • No additional pathologic finding in tumor specimen
  • No direct extension of malignant neoplasm identified
  • No peritumoral lymphocytic response
  • No regional lymph node metastasis
  • Non-diabetic hypoglycemia
  • Non-viable tumor present in specimen
  • Obstruction of aortic valve due to neoplasm
  • Obstruction of inferior vena cava
  • Obstruction of mitral valve due to neoplasm
  • Obstruction of pulmonary valve due to neoplasm
  • Obstruction of superior vena cava
  • Obstruction of superior vena cava due to neoplasm
  • Obstruction of tricuspid valve due to neoplasm
  • Occlusion of inferior vena cava
  • Occlusion of inferior vena cava due to neoplasm
  • Occlusion of superior vena cava
  • Occlusion of superior vena cava due to neoplasm
  • Opsoclonus-myoclonus syndrome
  • Osteitis deformans in neoplastic disease
  • Ovarian surgical margin, involved by tumor
  • Pancreatic surgical margin, involved by tumor
  • Papillary tumor configuration
  • Paraneoplastic autonomic dysfunction
  • Paraneoplastic cerebellar degeneration
  • Paraneoplastic encephalitis
  • Paraneoplastic encephalomyelitis
  • Paraneoplastic fever
  • Paraneoplastic hypertrophic osteoarthropathy
  • Paraneoplastic hypokalemia
  • Paraneoplastic hyponatremia
  • Paraneoplastic isolated brainstem encephalitis
  • Paraneoplastic limbic encephalitis
  • Paraneoplastic motor neurone disease
  • Paraneoplastic myoclonus
  • Paraneoplastic myositis
  • Paraneoplastic neuropathy
  • Paraneoplastic opsoclonus myoclonus syndrome
  • Paraneoplastic peripheral neuropathy
  • Paraneoplastic pruritus
  • Paraneoplastic retinopathy
  • Paraneoplastic sensorimotor neuropathy
  • Paraneoplastic sensory neuropathy
  • Paraneoplastic subacute necrotic myelopathy
  • Paraneoplastic syndrome
  • Paraneoplastic uveitis
  • Paraneoplastic vasculitis
  • Partial obstructing tumor
  • Pathologic fracture of ankle at site of neoplasm
  • Pathologic fracture of bone at site of neoplasm
  • Pathologic fracture of bone of foot at site of neoplasm
  • Pathologic fracture of bone of hand at site of neoplasm
  • Pathologic fracture of cervical vertebra at site of neoplasm
  • Pathologic fracture of clavicle at site of neoplasm
  • Pathologic fracture of femur at site of neoplasm
  • Pathologic fracture of fibula at site of neoplasm
  • Pathologic fracture of humerus at site of neoplasm
  • Pathologic fracture of lumbar vertebra at site of neoplasm
  • Pathologic fracture of pelvis at site of neoplasm
  • Pathologic fracture of proximal femur at site of neoplasm
  • Pathologic fracture of radius at site of neoplasm
  • Pathologic fracture of sacral vertebra at site of neoplasm
  • Pathologic fracture of scapula at site of neoplasm
  • Pathologic fracture of tibia at site of neoplasm
  • Pathologic fracture of ulna at site of neoplasm
  • Pathologic fracture of vertebra at site of neoplasm
  • Pathological fracture - hand
  • Pathological fracture - upper arm
  • Pathological fracture of ankle
  • Pathological fracture of cervical vertebra
  • Pathological fracture of clavicle
  • Pathological fracture of fibula
  • Pathological fracture of left clavicle
  • Pathological fracture of left clavicle due to neoplastic disease
  • Pathological fracture of left femur
  • Pathological fracture of left femur due to neoplastic disease
  • Pathological fracture of left hip
  • Pathological fracture of left humerus
  • Pathological fracture of left humerus due to neoplasm
  • Pathological fracture of lumbar vertebra
  • Pathological fracture of pelvis
  • Pathological fracture of proximal end of femur
  • Pathological fracture of proximal left femur due to neoplastic disease
  • Pathological fracture of proximal right femur due to neoplastic disease
  • Pathological fracture of radius
  • Pathological fracture of right femur
  • Pathological fracture of right femur due to neoplastic disease
  • Pathological fracture of right foot
  • Pathological fracture of right foot due to neoplastic disease
  • Pathological fracture of right hip
  • Pathological fracture of right humerus
  • Pathological fracture of right humerus due to neoplasm
  • Pathological fracture of sacral vertebra
  • Pathological fracture of scapula
  • Pathological fracture of thoracic vertebra
  • Pathological fracture of thoracic vertebra due to neoplastic disease
  • Pathological fracture of tibia
  • Pathological fracture of ulna
  • Pathological fracture of vertebra
  • Pathology examination findings indeterminate
  • Pericarditis secondary to neoplasia
  • Pericarditis secondary to primary tumor
  • Peritumoral lymphocytic response finding
  • Pigmented tumor
  • Plasma cell dyscrasia with polyneuropathy
  • Pleura, bronchial surgical margin, involved by tumor
  • Pleura, chest wall surgical margin, involved by tumor
  • Pleura, diaphragmatic surgical margin, involved by tumor
  • Pleura, esophageal surgical margin, involved by tumor
  • Pleura, extrapleural chest wall surgical margin, involved by tumor
  • Pleura, mediastinal surgical margin, involved by tumor
  • Pleura, pericardial surgical margin, involved by tumor
  • Pleura, pulmonary vascular surgical margin, involved by tumor
  • Pleura, tracheal surgical margin, involved by tumor
  • Pleura, vertebral body surgical margin, involved by tumor
  • Pleural effusion due to another disorder
  • Pleural effusion due to neoplastic disease
  • Pleural surgical margin, involved by tumor
  • Polymyositis
  • Posterior cord syndrome due to neoplasm
  • Postoperative presence of residual neoplasm following excision of neoplasm
  • Postoperative unintended residual tumor following excision of tumor
  • Primary site synchronous tumor finding
  • Primary site synchronous tumors present
  • Progesterone receptor negative neoplasm
  • Progesterone receptor positive tumor
  • Prolactin receptor positive tumor
  • Prostate surgical margin, involved by tumor
  • Prostate, apical surgical margin, involved by tumor
  • Prostate, deep radial surgical margin, involved by tumor
  • Prostate, seminal vesicle base surgical margin, involved by tumor
  • Prostate, urethral surgical margin, involved by tumor
  • Protruding tumor lesion
  • Proximal pancreatic surgical margin, involved by tumor
  • Proximal renal margin, partial nephrectomy only, involved by tumor
  • Proximal ureteral surgical margin, involved by tumor
  • Pulmonary venous hypertension due to compression of pulmonary great vein
  • Pulmonary venous hypertension due to compression of pulmonary great vein by neoplasm
  • Pushing tumor border
  • Radiculopathy due to neoplastic disease
  • Raised tumor
  • Rectum, deep surgical margin, focal, involved by tumor
  • Rectum, deep surgical margin, involved by tumor
  • Rectum, deep surgical margin, multifocal, involved by tumor
  • Rectum, inferior lateral surgical margin, involved by tumor
  • Rectum, lateral surgical margin, involved by tumor
  • Rectum, left lateral surgical margin, involved by tumor
  • Rectum, right lateral surgical margin, involved by tumor
  • Rectum, superior lateral surgical margin, involved by tumor
  • Rectum, unknown surgical margin, involved by tumor
  • Recurrent neoplasm
  • Regional lymph nodes cannot be assessed
  • Regression involving 75 percent or more of tumor, present
  • Regression involving less than 75 percent of tumor, present
  • Regression of tumor absent
  • Renal capsular surgical margin, involved by tumor
  • Renal pelvis surgical margin, involved by tumor
  • Residual tumor present
  • Restriction of coronary artery orifice due to neoplasm
  • Right parametrial surgical margin, involved by tumor
  • Right ventricular outflow tract obstruction due to neoplasm
  • Rupture of neoplasm
  • Secondary cerebellar degeneration
  • Seminal vesicle absent in tumor specimen
  • Sequelae of neoplastic diseases
  • Size of base of tumor on transillumination cannot be determined
  • Small tumor
  • Solid tumor configuration
  • Solid, entirely encapsulated tumor
  • Solid, partially encapsulated tumor
  • Specimen involvement by macroscopic tumor present
  • Spinal cord compression due to neoplasm
  • Stomach surgical margin, involved by tumor
  • Stomach, distal surgical margin, involved by tumor
  • Stomach, mesenteric surgical margin, involved by tumor
  • Stomach, proximal surgical margin, involved by tumor
  • Subacute necrotic myelopathy
  • Surgical bronchial margin involved by tumor
  • Surgical circumferential margin finding
  • Surgical circumferential margin involvement by tumor cannot be assessed
  • Surgical circumferential margin involvement by tumor not applicable
  • Surgical deep margin involvement by tumor cannot be assessed
  • Surgical distal margin involved by tumor
  • Surgical distal margin involvement by tumor cannot be assessed
  • Surgical lateral margin involved by tumor
  • Surgical margin involved by tumor
  • Surgical margin involvement by tumor absent
  • Surgical margin involvement by tumor cannot be assessed
  • Surgical margin involvement by tumor indeterminate
  • Surgical margin involvement by tumor not applicable
  • Surgical margin of optic nerve involved by tumor
  • Surgical margin of renal vessel involved by tumor
  • Surgical margin uninvolved by tumor
  • Surgical posterior retroperitoneal pancreatic margin involved by tumor
  • Surgical spermatic cord margin involved by tumor
  • Surgical spermatic cord margin involvement by tumor cannot be assessed
  • Surgical spermatic cord margin uninvolved by tumor
  • Testis surgical margin, involved by tumor
  • Thrombosis of inferior vena cava
  • Thrombosis of vena cava
  • Thyroid surgical margin, involved by tumor
  • Tissue specimen fragmented
  • Trophoblast, hysterectomy cervical/vaginal surgical margin, involved by tumor
  • Trophoblast, hysterectomy surgical margin, involved by tumor
  • Tumor border behavior finding
  • Tumor calcification
  • Tumor configuration
  • Tumor configuration cannot be determined
  • Tumor confined within capsule
  • Tumor contained within organ capsule
  • Tumor embolus
  • Tumor extends to organ capsule
  • Tumor flare
  • Tumor hyperprogression
  • Tumor infiltration by lymphocytes absent
  • Tumor infiltration by lymphocytes brisk
  • Tumor infiltration by lymphocytes non-brisk
  • Tumor infiltration by lymphocytes present
  • Tumor involvement of noncontiguous structures absent
  • Tumor location after sectioning cannot be determined
  • Tumor location cannot be determined
  • Tumor metastasis to non-regional lymph nodes not applicable
  • Tumor necrosis absent
  • Tumor necrosis cannot be determined
  • Tumor nodule site cannot be assessed
  • Tumor nodule size cannot be assessed
  • Tumor of advanced extent
  • Tumor of indeterminate configuration
  • Tumor of minimal extent
  • Tumor of moderate extent
  • Tumor of unknown origin
  • Tumor pigmentation cannot be determined
  • Tumor pigmentation indeterminate
  • Tumor pigmentation, diffuse
  • Tumor pigmentation, patchy/focal
  • Tumor progression
  • Tumor pseudoprogression
  • Tumor regression finding
  • Tumor site cannot be determined
  • Tumor site indeterminate
  • Tumor site not applicable
  • Tumor site not specified
  • Tumor size after sectioning cannot be determined
  • Tumor size cannot be assessed
  • Tumor size cannot be assessed, specimen fragmented
  • Tumor size finding
  • Tumor size not applicable
  • Tumor size, invasive component, cannot be determined
  • Tumor stage cannot be determined
  • Tumor surgically resectable
  • Tumor surgically unresectable
  • Tumor thrombus of inferior vena cava
  • Tumor ulceration absent
  • Ulcerated tumor configuration
  • Unifocal tumor
  • Unpigmented tumor
  • Upper aerodigestive tract surgical margin, involved by tumor
  • Ureter, renal pelvis surgical margin, involved by tumor
  • Ureteral surgical margin, involved by tumor
  • Uterine cervix surgical margin, involved by tumor
  • Vaginal surgical margin, involved by tumor
  • Vascularization of tumor tissue
  • Very large tumor
  • Viable tumor present in specimen
  • Visual cortex disorder due to neoplasm
  • Visual pathway disorder due to neoplasm
  • Vitreous cells
  • X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection and neoplasia

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Arthropathy
      • in (due to)
        • neoplastic disease NOS (see also Neoplasm)
    • Ataxia, ataxy, ataxic
      • cerebellar (hereditary)
        • in
          • neoplastic disease
    • Atrophy, atrophic(of)
      • systemic affecting central nervous system
        • in
          • neoplastic disease
    • Compression
      • nerve
        • root or plexus NOS (in)
          • neoplastic disease
    • Dermatomyositis(acute) (chronic)
      • in (due to) neoplastic disease
    • Dermatopolymyositis
      • in neoplastic disease
    • Encephalopathy(acute)
      • in (due to) (with)
        • neoplastic disease (see also Neoplasm)
    • Myasthenia
      • syndrome
        • in
          • neoplastic disease
    • Myelopathy(spinal cord)
      • in (due to)
        • neoplastic disease
    • Neuromyopathy
      • paraneoplastic (see also, Neoplasm, by site, if known)
    • Neuropathy, neuropathic
      • paraneoplastic (sensorial) (Denny Brown) (see also, Neoplasm, by site, if known)
    • Osteitis
      • deformans
        • in (due to)
          • neoplastic disease
    • Palsy
      • cranial nerve
        • multiple
          • in
            • neoplastic disease
    • Polyneuropathy(peripheral)
      • in (due to)
        • neoplastic disease
    • Syndrome
      • myasthenic
        • in
          • neoplastic disease

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Paraneoplastic Cerebellar Degeneration

    cerebellar degeneration associated with a remote neoplasm. clinical manifestations include progressive limb and gait ataxia; dysarthria; and nystagmus, pathologic. the histologic type of the associated neoplasm is usually carcinoma or lymphoma. pathologically the cerebellar cortex and subcortical nuclei demonstrate diffuse degenerative changes. anti-purkinje cell antibodies (anti-yo) are found in the serum of approximately 50% of affected individuals. (adams et al., principles of neurology, 6th ed, p686)

  • Limbic Encephalitis

    a paraneoplastic syndrome marked by degeneration of neurons in the limbic system. clinical features include hallucinations, loss of episodic memory; anosmia; ageusia; temporal lobe epilepsy; dementia; and affective disturbance (depression). circulating anti-neuronal antibodies (e.g., anti-hu; anti-yo; anti-ri; and anti-ma2) and small cell lung carcinomas or testicular carcinoma are frequently associated with this syndrome.

  • Dermatomyositis

    a subacute or chronic inflammatory disease of muscle and skin, marked by proximal muscle weakness and a characteristic skin rash. the illness occurs with approximately equal frequency in children and adults. the skin lesions usually take the form of a purplish rash (or less often an exfoliative dermatitis) involving the nose, cheeks, forehead, upper trunk, and arms. the disease is associated with a complement mediated intramuscular microangiopathy, leading to loss of capillaries, muscle ischemia, muscle-fiber necrosis, and perifascicular atrophy. the childhood form of this disease tends to evolve into a systemic vasculitis. dermatomyositis may occur in association with malignant neoplasms. (from adams et al., principles of neurology, 6th ed, pp1405-6)

  • Polymyositis

    diseases characterized by inflammation involving multiple muscles. this may occur as an acute or chronic condition associated with medication toxicity (drug toxicity); connective tissue diseases; infections; malignant neoplasms; and other disorders. the term polymyositis is frequently used to refer to a specific clinical entity characterized by subacute or slowly progressing symmetrical weakness primarily affecting the proximal limb and trunk muscles. the illness may occur at any age, but is most frequent in the fourth to sixth decade of life. weakness of pharyngeal and laryngeal muscles, interstitial lung disease, and inflammation of the myocardium may also occur. muscle biopsy reveals widespread destruction of segments of muscle fibers and an inflammatory cellular response. (adams et al., principles of neurology, 6th ed, pp1404-9)

  • BAP1-Inactivated Melanocytoma|BAP1-Deficient Tumor|BAP1-Inactivated Cutaneous Melanocytic Neoplasm|BAP1-Inactivated Cutaneous Melanocytic Tumor|BAP1-Inactivated Cutaneous Melanocytoma|BAP1-Inactivated Melanocytic Neoplasm|BAP1-Inactivated Melanocytic Tumor|BAP1-Inactivated Nevus|BAP1-Inactivated Skin Melanocytic Neoplasm|BAP1-Inactivated Skin Melanocytic Tumor|BAP1-Inactivated Spitzoid Nevus|BAPoma|BIM|BIMT|MBAIT|Melanocytic BAP1-Mutated Atypical Intradermal Tumor|Skin BAP1-Inactivated Melanocytoma|Wiesner Nevus

    a cutaneous melanocytoma caused by the inactivation of bap1 tumor suppressor gene. it is characterized by the presence of a predominantly intradermal proliferation of large epithelioid melanocytes with a large amount of eosinophilic cytoplasm, and vesicular nuclei with prominent nucleoli. progression to melanoma is infrequent.

  • Benign Conjunctival Melanocytic Neoplasm

    a conjunctival melanocytic neoplasm characterized by the absence of malignant morphological characteristics and metastases. this category includes melanocytic nevus, benign epithelial melanosis of the conjunctiva, and wnt-activated deep penetrating/plexiform melanocytoma (nevus).

  • Conjunctival Melanocytic Neoplasm|Conjunctival Melanocytic Tumor

    a melanocytic neoplasm that arises from the conjunctiva. this category includes conjunctival nevi, conjunctival melanocytic intraepithelial lesions, and conjunctival melanomas.

  • Cutaneous Melanocytic Neoplasm|Melanocytic Neoplasm of Skin|Melanocytic Skin Neoplasm|Skin Melanocytic Neoplasm|Skin Melanocytic Neoplasm

    a neoplasm that arises from melanocytes in the skin. this category includes nevi, melanocytomas, and melanomas.

  • Eyelid Melanocytic Neoplasm

    a melanocytic neoplasm that arises from the eyelid. this category includes nevi and melanomas.

  • MITF Pathway-Activated Melanocytic Tumor|MITF Pathway-Activated Melanocytic Neoplasm|Skin MITF Pathway-Activated Melanocytic Tumor

    a cutaneous neoplasm associated with mitf gene rearrangement and either actin-mitf translocation or mitf-crem translocation. it is composed of large cells with clear cytoplasm that exhibit melanocytic differentiation and proliferate in the dermis. it presents as a single non-pigmented cutaneous nodule.

  • Uveal Melanocytic Neoplasm|Uveal Melanocytic Tumor

    a melanocytic neoplasm that arises from the iris, ciliary body, and choroid. this category includes nevi, melanocytomas, and melanomas.

  • Paraneoplastic Cerebellar Degeneration

    a rare, immune-mediated disorder characterized by cerebellar degeneration due to the presence of an often undetected malignancy (usually carcinoma or lymphoma) in an anatomic site other than the cerebellum. signs and symptoms include progressive ataxia, dysarthria, and nystagmus.

  • Limbic Encephalitis

    a rare disorder characterized by degenerative changes in the limbic area of the brain. causes include infections and autoimmune conditions; it may also manifest as a paraneoplastic syndrome, most often caused by small cell lung carcinoma. signs and symptoms include behavioral changes, hallucinations and dementia.

  • Adult Primary Meningeal Melanocytic Neoplasm|Primary Meningeal Melanocytic Neoplasm

    a primary meningeal melanocytic neoplasm that occurs in adults.

  • BAP1-Inactivated Skin Melanocytic Neoplasm|BAP1-Deficient Tumor|BAP1-Inactivated Cutaneous Melanocytic Neoplasm|BAP1-Inactivated Cutaneous Melanocytic Tumor|BAP1-Inactivated Melanocytic Neoplasm|BAP1-Inactivated Melanocytic Tumor|BAPoma|BIMT

    a group of cutaneous melanocytic neoplasms that includes the combined bap1-inactivated nevus and the bap1-inactivated melanocytoma.

  • Central Nervous System Melanocytic Neoplasm|CNS Melanocytic Neoplasm|CNS Melanocytic Tumor|Central Nervous System Melanocytic Neoplasms|Central Nervous System Melanocytic Tumor|Melanocytic Neoplasm of CNS|Melanocytic Neoplasm of Central Nervous System|Melanocytic Neoplasm of the CNS|Melanocytic Neoplasm of the Central Nervous System|Melanocytic Tumor of CNS|Melanocytic Tumor of Central Nervous System|Melanocytic Tumor of the CNS|Melanocytic Tumor of the Central Nervous System

    a primary tumor of the central nervous system that arises from leptomeningeal melanocytes. it may present as a diffuse proliferative leptomeningeal process (often as a component of the neurocutaneous melanosis complex) or as a distinct mass lesion.

  • Circumscribed Meningeal Melanocytic Neoplasm|Circumscribed Meningeal Melanocytic Tumor

    a circumscribed neoplasm that arises from leptomeningeal melanocytes. this category includes meningeal melanocytoma, meningeal melanoma, and meningeal melanocytoma of intermediate grade.

  • Head and Neck Melanocytic Neoplasm

    a melanocytic neoplasm that arises from the skin or mucosal sites in the head and neck region.

  • Malignant Melanotic Peripheral Nerve Sheath Tumor|MMNST|Malignant Melanocytic Neoplasm of Peripheral Nerve Sheath|Malignant Melanocytic Neoplasm of the Peripheral Nerve Sheath|Malignant Melanocytic Peripheral Nerve Sheath Tumor|Malignant Melanotic Nerve Sheath Tumor|Malignant Melanotic Schwannian Tumor|Melanocytic MPNST|Melanotic MPNST

    a rare variant of malignant peripheral nerve sheath tumor. it is characterized by the presence of malignant cells that contain melanin.

  • Melanocytic Neoplasm

    a benign or malignant, primary or metastatic neoplasm affecting the melanocytes.

  • Primary Meningeal Melanocytic Neoplasm

    a benign, intermediate, or malignant circumscribed or diffuse neoplasm that arises from melanocytes in the leptomeninges. it includes meningeal melanocytoma, meningeal melanoma, meningeal melanocytoma of intermediate grade, and meningeal melanocytosis.

  • Skin Melanocytic Neoplasm|Cutaneous Melanocytic Neoplasm|Melanocytic Neoplasm of Skin|Melanocytic Skin Neoplasm

    a neoplasm that arises from melanocytes in the skin.

  • Vulvar Melanocytic Neoplasm

    a neoplasm that originates from melanocytes and arises from the vulva. this category includes congenital and acquired melanocytic nevus, blue nevus, dysplastic melanocytic nevus, atypical melanocytic nevus, genital type, and melanoma.

  • Adult Central Nervous System Melanocytic Neoplasm|Adult Central Nervous System Melanocytic Tumor|Adult Primary Central Nervous System Melanocytic Neoplasm|Adult Primary Meningeal Melanocytic Neoplasm|Primary Meningeal Melanocytic Neoplasm

    a melanocytic neoplasm that arises from the leptomeninges and occurs during adulthood.

  • BAP1-Inactivated Melanocytoma|BAP1-Deficient Tumor|BAP1-Inactivated Cutaneous Melanocytic Neoplasm|BAP1-Inactivated Cutaneous Melanocytic Tumor|BAP1-Inactivated Cutaneous Melanocytoma|BAP1-Inactivated Melanocytic Neoplasm|BAP1-Inactivated Melanocytic Tumor|BAP1-Inactivated Nevus|BAP1-Inactivated Skin Melanocytic Neoplasm|BAP1-Inactivated Skin Melanocytic Tumor|BAP1-Inactivated Spitzoid Nevus|BAPoma|BIM|BIMT|MBAIT|Melanocytic BAP1-Mutated Atypical Intradermal Tumor|Wiesner Nevus

    a cutaneous melanocytoma caused by the inactivation of bap1 tumor suppressor gene. it is characterized by the presence of a predominantly intradermal proliferation of large epithelioid melanocytes with a large amount of eosinophilic cytoplasm, and vesicular nuclei with prominent nucleoli. progression to melanoma is infrequent.

  • Central Nervous System Melanocytic Neoplasm|CNS Melanocytic Neoplasm|CNS Melanocytic Tumor|Central Nervous System Melanocytic Tumor|Primary Central Nervous System Melanocytic Neoplasm|Primary Central Nervous System Melanocytic Tumor|Primary Meningeal Melanocytic Neoplasm|Primary Meningeal Melanocytic Tumor

    a melanocytic neoplasm that arises from the leptomeninges. this category includes diffuse proliferative processes (melanocytosis and melanomatosis) and circumscribed processes (melanocytoma and melanoma).

  • Childhood Melanocytic Neoplasm|Pediatric Melanocytic Neoplasm

    a benign, atypical, or malignant neoplasm that arises from and is composed of melanocytes and occurs during childhood.

  • Circumscribed Meningeal Melanocytic Neoplasm|Circumscribed Meningeal Melanocytic Tumor

    a circumscribed neoplasm that arises from leptomeningeal melanocytes. this category includes meningeal melanocytoma and meningeal melanoma.

  • Conjunctival Melanocytic Neoplasm|Conjunctival Melanocytic Tumor

    a melanocytic neoplasm that arises from the conjunctiva. this category includes conjunctival nevus, conjunctival melanocytic intraepithelial lesions, and conjunctival melanoma.

  • Diffuse Meningeal Melanocytic Neoplasm

    a diffuse proliferation of melanocytes that affects the leptomeninges. this category includes melanocytosis and melanomatosis.

  • Melanocytic Neoplasm

    a benign, atypical, or malignant neoplasm that arises from and is composed of melanocytes. this category includes melanocytic nevi, melanocytomas, and melanomas.

  • MITF Pathway-Activated Melanocytic Tumor|MITF Pathway-Activated Melanocytic Neoplasm

    a cutaneous neoplasm associated with mitf gene rearrangement and either actin-mitf translocation or mitf-crem translocation. it is composed of large cells with clear cytoplasm that exhibit melanocytic differentiation and proliferate in the dermis. it presents as a single non-pigmented cutaneous nodule.

  • Skin Melanocytic Neoplasm|Cutaneous Melanocytic Neoplasm|Melanocytic Neoplasm of Skin|Melanocytic Skin Neoplasm

    a neoplasm that arises from melanocytes in the skin. this category includes nevi, melanocytomas, and melanomas.

  • Uveal Melanocytic Neoplasm|Uveal Melanocytic Tumor

    a melanocytic neoplasm that arises from the iris, ciliary body, and choroid. this category includes nevus and its subtype melanocytoma, and melanoma.

  • Vulvar Melanocytic Neoplasm

    a neoplasm that originates from melanocytes and arises from the vulva. this category includes congenital and acquired melanocytic nevus, blue nevus, dysplastic melanocytic nevus, atypical melanocytic nevus of genital type, and melanoma.

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
unknown site or unspecifiedC80.1C79.9D09.9D36.9D48.9D49.9

Convert D49.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
239.9 Neoplasm NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D49.9Overview

Is D49.9 (Neoplasms of unspecified behavior) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of unspecified behavior of unspecified site on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D49.9 group to?

When neoplasm of unspecified behavior of unspecified site is the principal diagnosis on an inpatient stay, it groups to MS-DRG 826, 827, 828, 829, 830, 843, 844, 845, with relative weights from 0.8516 to 4.6778 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D49.9?

Under the General Equivalence Mappings, neoplasm of unspecified behavior of unspecified site converts to ICD-9-CM 239.9 (neoplasm NOS). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.