Acquired digital fibrokeratoma in Adult
The etiology is unknown, but ADF is thought to develop after local trauma or subclinical injury.
D23.9 – Other benign neoplasm of skin, unspecified
110986000 – Acquired digital fibrokeratoma
Differential Diagnosis & Pitfalls
- Supernumerary digit – Present at birth, usually on the medial / ulnar side of the fifth digit.
- Periungual fibromas – These lesions, also called Koenen tumors, are sometimes associated with tuberous sclerosis and develop in late childhood around toenails or, less often, around fingernails; periungual fibromas have histologic findings quite similar to those of ADF.
- Verruca vulgaris – Viral-induced neoplasms often have brown / purple dots (thrombosed capillaries) centrally.
- Eccrine poroma – A proliferation of ductal epithelium, presenting usually as a sessile vascular papule of acral skin surrounded by an indentation ("moat and hillock").
- Lobular capillary hemangioma (pyogenic granuloma) – Rapidly growing, exophytic, and pedunculated vascular papule that is prone to easy bleeding.
- Cutaneous horns or corns – Hyperkeratosis and flat surface; sometimes painful.
- Dermatofibroma – Rarely seen on palmoplantar surfaces, this type of lesion has a characteristic tethering of the overlying epidermis to the underlying fibrotic lesion that creates a "dimple" with lateral compression (Fitzpatrick sign).
- Cutaneous squamous cell carcinoma – Variable presentation. Usually lacks the collarette of scale present in acral digital fibrokeratoma. Hyperkeratosis and nail loss may be present.
- Aggressive digital papillary adenocarcinoma – A rare malignant tumor, presenting as a solitary asymptomatic swelling or cystic nodule; differentiated chiefly by histologic examination.