digital myxoma

Digital myxoma generally presents as a slowly growing, solitary, painful, cystic and dome-shaped nodule reaching a maximal diameter of no more than 10–20 mm. It is localized in the superficial dermis of the distal and dorsal portions of the fingers, and far less commonly occurs in the toes.

The lesion tends to occur in adults with a marked preference for females.

It is a benign lesion, although recurrence after incomplete excision is
common.

Histologically, the lesion is relatively well circumscribed but unencapsulated, and is composed of an abundant hypocellular and avascular myxoid stroma containing variably prominent bland spindle-shaped and stellate fibroblasts without cellular or nuclear atypia.

Cystic cavities are sometimes seen but these are not lined by a connective tissue lining as seen in ganglia.

Differential diagnosis

 superficial angiomyxoma

• In the differential diagnosis with superficial angiomyxoma, the specific clinical site, circumscription, relative paucity of vessels and absence of neutrophils favour the diagnosis of a digital myxoma.

References

 Myxoid tumours of soft tissue. Graadt van Roggen JF, Hogendoorn PC, Fletcher CD. Histopathology. 1999 Oct;35(4):291-312. PMID: 10564384