[Case for diagnosis. Dermatofibrosarcoma protuberans].

A 30-year-old woman developed a slowly progressive reddish-violet multinodular rubbery lesion, measuring 20 x 10 cm in diameter, on the upper outer quadrant of her right breast four years after the surgical excision of a dermatofibrosarcoma protuberans (DFSP) in the same area. The diagnosis of DFSP was confirmed histologically and by positive immunomarkers at immunohistochemistry. A complete excision was performed and after a 2-year follow-up no recurrence was observed.

Detection of polyomavirus major capsid antigen (VP-1) in human pilomatricomas.

The family Polyomaviridae is composed of small, non-enveloped, double-stranded DNA viruses widely used to study cell transformation in vitro and tumor induction in vivo. The development of pilomatricomas in mice experimentally infected with polyomavirus led us to detect the viral major capsid protein VP-1 in human pilomatricomas. This tumor, even uncommon, is one of the most frequent benign hair follicle tumors in humans and is composed of proliferating matrix cells that undergo keratinization, and form cystic neoplasms.

Cutaneous true histiocytic malignancy: true histiocytic lymphoma.

True histiocytic malignancies (THM) are controversial disorders that are being re-evaluated with modern cellular and molecular biology techniques. True histiocytic lymphoma (THL) is a low-incidence, poor-prognosis THM. It mainly affects the skin, gastrointestinal tract, and bone tissues.