A 37 year old female has a contracture involving the third digit of her left hand that prevents her from fully extending this finger. The lesion has gradually developed over the past 6 months. A firm, hard, cordlike, 1x3 cm area is palpable beneath the skin of the left palm. Histologically this mass is most likely to be composed of

She has superficial fibromatosis that has produced a lesion best known as a Dupuytren contracture. These lesions contain mature fibroblasts surrounded by dense collagen. A hard, firm lesion of this size is unlikely to be a malignancy. An injury with granulation tissue should give rise to a stable scar, without such severe retraction. Dystrophic calcification refers to calcification that occurs in necrotic tissues; it is not commonly a localized mass.