2026 ICD-10-CM Diagnosis Code D48.9Neoplasm of uncertain behavior, unspecified
ICD-10-CM Codes›C00–D49›D37-D48›D48
- Billable — Valid for Submission
- Not Chronic
ICD-10-CM D48.9
D48.9 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior, unspecified. 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
D48.9
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of uncertain behavior, unspecified
Short Description
Neoplasm of uncertain behavior, unspecified
Same as the full description in the CMS dataset.
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Apudoma
- Benign neoplasm of muscle of neck
- Epithelioid inflammatory myofibroblastic sarcoma
- Extragonadal teratoma
- Fibromatosis colli
- Ganglioglioma
- Giant cell tumor
- Hemangioendothelioma
- Histologic features of tumor cannot be determined
- Histologic type of tumor-associated epithelial lesion cannot be determined
- Inflammatory myofibroblastic tumor
- Juvenile hemangioendothelioma
- Neoplasm of muscle of neck
- Neoplastic disease of uncertain behavior
- NTRK-rearranged spindle cell neoplasm
- Perivascular epithelioid cell neoplasm of uncertain behavior
- Teratoma
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
Apudoma
a general term collectively applied to tumors associated with the apud cells series, irrespective of their specific identification.Hypothalamic Neoplasms
benign and malignant tumors of the hypothalamus. pilocytic astrocytomas and hamartomas are relatively frequent histologic types. neoplasms of the hypothalamus frequently originate from adjacent structures, including the optic chiasm, optic nerve (see optic nerve neoplasms), and pituitary gland (see pituitary neoplasms). relatively frequent clinical manifestations include visual loss, developmental delay, macrocephaly, and precocious puberty. (from devita et al., cancer: principles and practice of oncology, 5th ed, p2051)Teratoma
a true neoplasm composed of a number of different types of tissue, none of which is native to the area in which it occurs. it is composed of tissues that are derived from three germinal layers, the endoderm, mesoderm, and ectoderm. they are classified histologically as mature (benign) or immature (malignant). (from devita jr et al., cancer: principles & practice of oncology, 3d ed, p1642)Hemangioendothelioma
a neoplasm derived from blood vessels, characterized by numerous prominent endothelial cells that occur singly, in aggregates, and as the lining of congeries of vascular tubes or channels. hemangioendotheliomas are relatively rare and are of intermediate malignancy (between benign hemangiomas and conventional angiosarcomas). they affect men and women about equally and rarely develop in childhood. (from stedman, 25th ed; holland et al., cancer medicine, 3d ed, p1866)Hemangioendothelioma, Epithelioid
a tumor of medium-to-large veins, composed of plump-to-spindled endothelial cells that bulge into vascular spaces in a tombstone-like fashion. these tumors are thought to have borderline aggression, where one-third develop local recurrences, but only rarely metastasize. it is unclear whether the epithelioid hemangioendothelioma is truly neoplastic or an exuberant tissue reaction, nor is it clear if this is equivalent to kimura's disease (see angiolymphoid hyperplasia with eosinophilia). (segen, dictionary of modern medicine, 1992)Ganglioglioma
rare indolent tumors comprised of neoplastic glial and neuronal cells which occur primarily in children and young adults. benign lesions tend to be associated with long survival unless the tumor degenerates into a histologically malignant form. they tend to occur in the optic nerve and white matter of the brain and spinal cord.APUD Cells
cells with the capacity to take up and decarboxylate the amine precursors dihydroxyphenylalanine or 5-hydroxytryptophan. this is a property of endocrine cells of neural and non-neural origin. apudoma is a general term collectively applied to tumors associated with apud cells.Angiolymphoid Hyperplasia with Eosinophilia
solitary or multiple benign cutaneous nodules comprised of immature and mature vascular structures intermingled with endothelial cells and a varied infiltrate of eosinophils, histiocytes, lymphocytes, and mast cells.Giant Cell Tumor of Bone|Benign Bone Giant Cell Tumor|GCTB|GIANT CELL TUMOR, BENIGN|Giant Cell Tumor of the Bone|Giant cell tumor of bone, NOS|Osteoclastoma|Osteoclastoma, Benign
a locally aggressive tumor that arises from the bone and is composed of mononuclear cells admixed with macrophages and osteoclast-like giant cells. it usually arises from the ends of long bones or the vertebrae. clinical presentation includes pain, edema, and decreased range of motion in the affected joint.Childhood Giant Cell Tumor of Bone|Pediatric Giant Cell Tumor of Bone
a giant cell tumor of bone that occurs during childhood.Childhood Tenosynovial Giant Cell Tumor|Pediatric Tenosynovial Giant Cell Tumor
a tenosynovial giant cell tumor that occurs during childhood.Giant Cell Tumor
a benign, intermediate, or malignant tumor that arises from the bone or soft tissue. it is characterized by the presence of multinucleated osteoclast-like giant cells.Giant Cell Tumor of Bone|Benign Bone Giant Cell Tumor|GCTB|GIANT CELL TUMOR, BENIGN|Giant Cell Tumor of the Bone|Giant cell tumor of bone, NOS|Osteoclastoma|Osteoclastoma, Benign
a benign but locally aggressive tumor that arises from the bone and is composed of mononuclear cells admixed with macrophages and osteoclast-like giant cells. it usually arises from the ends of long bones or the vertebrae. clinical presentation includes pain, edema, and decreased range of motion in the affected joint.Giant Cell Tumor of Soft Tissue|GCT-ST|Giant Cell Tumor of Low Malignant Potential|Giant cell tumor of soft parts, NOS|Osteoclastoma of Soft Tissue
a painless, well circumscribed tumor arising in soft tissue, usually of the upper and lower extremities. morphologically, it is characterized by a multinodular growth pattern. the cellular infiltrate is composed of mononuclear round or oval cells and multinucleated osteoclast-like giant cells, in a rich vascular stroma. it rarely metastasizes.Malignancy in Giant Cell Tumor of Bone|Dedifferentiated Giant Cell Tumor|Dedifferentiated Giant Cell Tumor|Giant Cell Bone Sarcoma|Giant Cell Bone Sarcoma|Giant Cell Sarcoma of Bone|Giant Cell Sarcoma of Bone|Giant Cell Sarcoma of the Bone|Giant Cell Sarcoma of the Bone|Giant cell sarcoma of bone|Giant cell tumor of bone, malignant|Malignancy in Giant Cell Tumor of the Bone|Malignant Giant Cell Tumor of Bone|OSTEOCLASTOMA, MALIGNANT
a malignant tumor that arises from the bone. it is characterized by the presence of an area of high grade sarcoma in an otherwise typical giant cell tumor (primary malignancy in giant cell tumor), or the presence of sarcoma in which the pre-existing giant cell tumor may or may not be apparent (secondary malignancy in giant cell tumor).Malignant Giant Cell Neoplasm|GIANT CELL TUMOR, MALIGNANT|Malignant Giant Cell Tumor|Malignant Giant Cell Tumor|Malignant tumor, giant cell type
a malignant neoplasm characterized by then presence of atypical giant cells.Malignant Tenosynovial Giant Cell Tumor|Giant cell tumor of tendon sheath, malignant|Malignant Giant Cell Neoplasm of Tendon Sheath|Malignant Giant Cell Neoplasm of the Tendon Sheath|Malignant Giant Cell Tumor of Tendon Sheath|Malignant Giant Cell Tumor of the Tendon Sheath|Malignant Tendon Sheath Giant Cell Neoplasm|Malignant Tendon Sheath Giant Cell Tumor|Malignant tenosynovial giant cell tumor
an uncommon malignant tumor arising from the tendon sheath. morphologically, it is characterized by the presence of a cellular infiltrate reminiscent of a giant cell tumor with prominent malignant characteristics. recurrent giant cell tumors with a sarcomatous dedifferentiation are included in this category as well.Osteoblastoma|Giant Osteoid Osteoma|Giant Osteoid Osteoma|Giant osteoid osteoma|OSTEOBLASTOMA, BENIGN|Ossifying Giant Cell Tumor|Ossifying Giant Cell Tumor|Osteoblastoma, NOS
a rare benign bone-forming neoplasm usually arising from the spine. it is a well-circumscribed lytic tumor that varies in size. the tumor is composed of woven bone trabeculae and shares similar histologic characteristics with the osteoid osteoma. surgical curettage is the treatment of choice. the prognosis is excellent.Tenosynovial Giant Cell Tumor, Diffuse Type|Diffuse Giant Cell Neoplasm of Tendon Sheath|Diffuse Giant Cell Neoplasm of Tenosynovium|Diffuse Giant Cell Neoplasm of the Tenosynovium|Diffuse Giant Cell Tumor of Tendon Sheath|Diffuse Giant Cell Tumor of Tenosynovium|Diffuse Giant Cell Tumor of the Tenosynovium|Diffuse Tenosynovial Giant Cell Neoplasm|Diffuse Tenosynovial Giant Cell Tumor|Pigmented Villonodular Synovitis
a locally aggressive, diffusely infiltrating tumor, arising in the tendon sheath. it is composed of synovial-like mononuclear cells, hemosiderin-laden macrophages, foam cells, and inflammatory cells. multinucleated osteoclast-like giant cells are usually present, although in a minority of cases they may be absent or rare. it predominantly affects young adults. symptoms include joint swelling, pain, and joint effusion.Tenosynovial Giant Cell Tumor, Localized Type|Localized Giant Cell Neoplasm of Tendon Sheath|Localized Giant Cell Neoplasm of Tenosynovium|Localized Giant Cell Neoplasm of the Tenosynovium|Localized Giant Cell Tumor of Tendon Sheath|Localized Giant Cell Tumor of Tenosynovium|Localized Giant Cell Tumor of the Tenosynovium|Localized Tenosynovial Giant Cell Neoplasm|Localized Tenosynovial Giant Cell Tumor|Nodular Tenosynovitis
a well-circumscribed, lobulated tumor, completely or partially covered by a fibrous capsule. it usually arises in the fingers. it is characterized by the presence of mononuclear cells, multinucleated osteoclast-like giant cells, hemosiderin-laden macrophages, foam cells, and an inflammatory infiltrate. the tumor is slow-growing, usually developing over several years. clinical presentation includes painless edema of the affected site.Tenosynovial Giant Cell Tumor|Fibrous Histiocytoma of Tendon Sheath|Fibrous histiocytoma of tendon sheath|Giant Cell Neoplasm of Tendon Sheath|Giant Cell Neoplasm of Tenosynovium|Giant Cell Neoplasm of the Tenosynovium|Giant Cell Tumor of Tendon Sheath|Giant Cell Tumor of Tenosynovium|Giant Cell Tumor of the Tenosynovium|Giant cell tumor of tendon sheath|Tendon Sheath Giant Cell Neoplasm|Tendon Sheath Giant Cell Tumor|Tenosynovial Giant Cell Neoplasm|Tenosynovial giant cell tumor
a tumor usually arising in the synovium of joints, bursa or tendon sheath. it is characterized by the presence of mononuclear cells, multinucleated osteoclast-like giant cells, hemosiderin-laden macrophages, foam cells, and an inflammatory infiltrate. according to the growth pattern, it is classified as localized or diffuse.Undifferentiated Pleomorphic Sarcoma with Osteoclast-Like Giant Cells|Giant Cell Fibrous Histiocytoma|Giant Cell Malignant Fibrous Histiocytoma|Malignant Giant Cell Neoplasm of Soft Parts|Malignant Giant Cell Tumor of Soft Parts|Malignant giant cell tumor of soft parts
an undifferentiated pleomorphic sarcoma characterized by the presence of osteoclast-like giant cells and cellular pleomorphism.Childhood Extragonadal Teratoma
an extragonadal teratoma that occurs during childhood.Extragonadal Teratoma
a teratoma that develops as a primary tumor in an anatomic site other than the testis or ovary.Immature Extragonadal Teratoma
an immature teratoma that develops as a primary tumor in an anatomic site other than the testis or ovary.
Table of NeoplasmsClinical
Convert D48.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
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 D48.9Overview
Is D48.9 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of uncertain behavior, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D48.9 group to?
When neoplasm of uncertain behavior, unspecified 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 D48.9?
Under the General Equivalence Mappings, neoplasm of uncertain behavior, unspecified converts to ICD-9-CM 238.9 (uncert behavior neo 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.
