2026 ICD-10-CM Diagnosis Code D23.9Other benign neoplasm of skin, unspecified

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

• Myopericytoma

  rare myofibroma-like perivascular soft tissue tumor, usually benign, characterized by concentric perivascular proliferation.

• Ganglioneuroma

  a benign neoplasm that usually arises from the sympathetic trunk in the mediastinum. histologic features include spindle cell proliferation (resembling a neurofibroma) and the presence of large ganglion cells. the tumor may present clinically with horner syndrome or diarrhea due to ectopic production of vasoactive intestinal peptide. (from devita et al., cancer: principles and practice of oncology, 5th ed, p966)

• Myofibroma

  a benign tumor that consists chiefly of fibrous connective tissue, with variable numbers of muscle cells forming portions of the neoplasm (from stedman's, 27th ed).

• Myofibromatosis

  a condition characterized by multiple formations of myofibromas (leiomyoma).

• Pilomatrixoma

  a tumor composed of cells resembling those of the hair matrix, which undergo 'mummification' and may calcify. it is a relatively uncommon tumor, which may occur at any age from infancy. the majority of patients are under 20, and females are affected more than males. the lesion is usually a solitary deep dermal or subcutaneous tumor 3-30 mm in diameter, situated in the head, neck, or upper extremity. (from rook et al., textbook of dermatology, 4th ed, p2401)

• Adenoma, Pleomorphic

  a benign, slow-growing tumor, most commonly of the salivary gland, occurring as a small, painless, firm nodule, usually of the parotid gland, but also found in any major or accessory salivary gland anywhere in the oral cavity. it is most often seen in women in the fifth decade. histologically, the tumor presents a variety of cells: cuboidal, columnar, and squamous cells, showing all forms of epithelial growth. (dorland, 27th ed)

• Syringoma

  a benign tumor of the sweat glands which is usually multiple and results from malformation of sweat ducts. it is uncommon and more common in females than in males. it is most likely to appear at adolescence, and further lesions may develop during adult life. it does not appear to be hereditary. (rook et al., textbook of dermatology, 4th ed, pp2407-8)

• Horner Syndrome

  a syndrome associated with defective sympathetic innervation to one side of the face, including the eye. clinical features include miosis; mild blepharoptosis; and hemifacial anhidrosis (decreased sweating)(see hypohidrosis). lesions of the brain stem; cervical spinal cord; first thoracic nerve root; apex of the lung; carotid artery; cavernous sinus; and apex of the orbit may cause this condition. (from miller et al., clinical neuro-ophthalmology, 4th ed, pp500-11)

• Leiomyoma

  a benign tumor derived from smooth muscle tissue, also known as a fibroid tumor. they rarely occur outside of the uterus and the gastrointestinal tract but can occur in the skin and subcutaneous tissue, probably arising from the smooth muscle of small blood vessels in these tissues.

• Cutaneous Junctional Nevus|Intraepidermal Nevus|Intraepidermal Nevus of Skin|Intraepidermal Nevus of the Skin|Intraepidermal nevus|Junctional Nevus of Skin|Junctional Nevus of the Skin|Junctional Skin Nevus|Skin Junction Nevus|Skin Junctional Melanocytic Nevus|Skin Junctional Nevus|junctional nevus

  a cutaneous nevus characterized by the presence of an intraepidermal proliferation of nevus cells. the nevus cells form multiple nests in the dermal-epidermal junction. it presents as a small, slightly raised, pigmented skin lesion.

• Becker Nevus|Becker's Nevus|Linear Papular Ectodermal-Mesodermal Hamartoma|Melanosis Neviformis|Pigmented Hairy Epidermal Nevus|Pigmented Hairy Nevus of Becker|Progressive Cribriform and Zosteriform Hyperpigmentation

  a benign lesion that is sometimes congenital and consists of an overgrowth of the epidermis and the presence of melanin-containing cells. it is found mostly in males and typically develops during childhood or adolescence, becoming darker and more hairy after puberty.

• Epidermal Nevus

  a benign, pigmented skin growth caused by an overgrowth of the epidermis. it is typically seen at birth, but can develop in early childhood or later in life. most cases are sporadic, but familial patterns of inheritance have been observed.

• Junctional Nevus|Intraepidermal Nevus|Intraepidermal Nevus of Skin|Intraepidermal Nevus of the Skin|Intraepidermal nevus|Junction Nevus|Junction nevus|Junctional Melanocytic Nevus|Junctional Melanocytoma|Junctional Nevus of Skin|Junctional Nevus of the Skin|Junctional Skin Nevus|Junctional nevus, NOS|junctional nevus

  a nevus characterized by the presence of an intraepidermal proliferation of nevus cells. the nevus cells form multiple nests in the dermal-epidermal junction. it presents as a small, slightly raised, pigmented skin lesion.

• Verrucous Nevus|Verrucous Epidermal Nevus

  a benign wart-like, pigmented skin lesion appearing on various parts of the body at birth or early in childhood, usually in linear groupings.

• Trichoadenoma

  a rare benign tumor of the hair follicle occurring usually in the face or buttocks.

• Basal Cell Nevus with Comedones

  a type of pilosebaceous hamartoma characterized by basal cell epitheliomata, epidermoid cysts and comedones, and epidermal atrophy.

• Trichofolliculoma

  a skin appendage neoplasm with follicular differentiation. it usually occurs in the head and neck region, particularly the face. it presents as a solitary dome-shaped small lesion. the clinical course is benign.

• Lipomatosis of Nerve|Fibrolipomatous Hamartoma of Peripheral Nerve|Neural Fibrolipoma|Peripheral Nerve Fibrolipomatous Hamartoma

  a tumor composed of mature adipocytes and fibrous tissue infiltrating the epineurium and peripheral nerves. it is often seen at birth or during childhood and may be associated with macrodactyly.

• Lipomatous Hamartoma

  a benign hamartomatous lesion composed predominantly of adipose tissue.

• Thymolipoma|Thymolipomatous Hamartoma

  a well-circumscribed tumor of the thymus composed of islands of normal thymic parenchyma and mature adipose tissue. it is not clear if thymolipoma is a neoplastic or non-neoplastic lesion.

• Osteoma Cutis

  heterotopic ossification of the skin not associated with a preexisting lesion or process, such as inflammation or neoplasia.

• Progressive Heterotopic Heteroplasia|Osteoma Cutis|Progressive Osseous Heteroplasia

  loss of function mutation(s) in the paternal allele of the gnas gene, encoding guanine nucleotide-binding protein g(s) subunit alpha isoforms short resulting in dermal ossification beginning in infancy, followed by increasing and extensive heterotopic bone formation in deep muscle and fascia.

• Pleomorphic Fibroma

  a benign, often polypoid, fibroblastic neoplasm characterized by bizarre pleomorphic cells. (who 2018)

• Large Cell Acanthoma

  a benign, well-circumscribed skin squamous lesion characterized by the presence of enlarged keratinocytes with nuclei twice the normal size. (who 2018)

• Junctional Nevus|Intraepidermal Nevus|Intraepidermal Nevus of Skin|Intraepidermal Nevus of the Skin|Intraepidermal nevus|Junction Nevus|Junction nevus|Junctional Melanocytic Nevus|Junctional Nevus of Skin|Junctional Nevus of the Skin|Junctional Skin Nevus|Junctional nevus, NOS|junctional nevus

  a nevus characterized by the presence of an intraepidermal proliferation of nevus cells. the nevus cells form multiple nests in the dermal-epidermal junction. it presents as a small, slightly raised, pigmented skin lesion.

• Spindle-Cell Predominant Trichodiscoma|Neurofollicular Hamartoma|SCPT

  a trichodiscoma characterized by the presence of abundant mucinous stroma and spindle-cell fibrocytic proliferation.

• Trichodiscoma

  a rare hamartomatous papular lesion that arises from the hair follicle. it shares morphological features with fibrofolliculoma, but in contrast to fibrofolliculoma, the predominant component is stroma.

• Trichofolliculoma

  a hair follicle lesion that presents as a solitary, colored, dome-shaped small papule. it consists of a central cystic follicular infundibulum from which numerous smaller hair follicles emanate into the surrounding dermis. the clinical course is benign.

• Trichogerminoma

  a rare subtype of trichoblastoma characterized by the presence of lobules of basaloid cells. the lobules are separated by fibrous stroma. it is associated with the expression of recurrent foxk1/grhl and gps2/grhl gene fusions.

• Dermal Nerve Sheath Myxoma

  a benign neoplasm with nerve sheath features that arises from the dermis and subcutaneous tissue. it manifests as an asymptomatic nodule and most often arises from the extremities. it is composed of spindle and epithelioid cells in a myxoid stroma.

• Pleomorphic Fibroma

  a benign fibroblastic dermal neoplasm characterized by the presence of bizarre pleomorphic cells. it is associated with rb1 gene deletion and presents with small polyps and papules affecting the extremities, trunk, and head and neck.

• Pleomorphic Onychomatricoma|Subungual Pleomorphic Fibroma|Unguioblastic Fibroma

  an onychomatricoma characterized by the presence of neoplastic fibroepithelial cells with multinucleated and pleomorphic nuclei.

• Myxoid Onychomatricoma

  an onychomatricoma characterized by the presence of myxoid stromal changes.

• Onychomatricoma

  a rare benign neoplasm that arises from the nail matrix and rarely proximal nail fold and is composed of fibroepithelial cells. it is usually located in fingers and less often in toes.

• Pigmented Onychomatricoma

  an onychomatricoma characterized by the presence of epithelial and nail plate melanin pigmentation.

• Proliferative Onychomatricoma

  an onychomatricoma characterized by the presence of marked epithelial proliferation.

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

Benign Tumors

Tumors are abnormal growths in your body. They can be either benign or malignant. Benign tumors aren't cancer. Malignant ones are. Benign tumors grow only in one place. They cannot spread or invade other parts of your body. Even so, they can be dangerous if they press on vital organs, such as your brain.

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