Histopathologic examination of the skin specimen demonstrated epidermal hyperplasia with compact orthokeratosis, thickening of the dermis with an increase of collagen bundles, and a slight proliferation of fibroblasts in the reticular dermis. Because the patient was asymptomatic and unconcerned about the appearance of his fingers, no treatment was prescribed.
Pachydermodactyly is a distinctive benign, acquired form of localized digital fibromatosis, which is characterized by asymptomatic swelling of the dorsum and sides of the proximal interphalangeal joints of both hands. The swelling appears as pink padlike lesions on the medial and/or lateral aspect of the proximal phalanges of the fingers, several or all of which may be involved. The lesions usually develop insidiously in male adolescents and tend to persist, causing minimal discomfort. The majority of reported cases are sporadic, although occasional isolated familial cases have been described.1 The histopathologic features are nonspecific, but epidermal hyperplasia, an increase of dermal collagen bundles, and a slight increase in the number of fibroblasts are usually observed.
Acquired Fusiform Swelling of the Fingers—Diagnosis. Arch Dermatol. 2005;141(8):1035-1040. doi:10.1001/archderm.141.8.1035-f