MALIGNANT PILOMATRICOMA - A CASE-REPORT

A 37-year-old man presented with a lobulated, ulcerated: tumoral mass localized to the right anterior mid-arm of 7 x 6 cm in diameter (Fig. 1). It had a IO-year history, with an accelerated asymptomatic growth in the last 3 years. The patient's physical examination was completely normal with no lymphadenopathy. The chest and abdominal computerized axial tomography (CAT) scan studies were normal. The lesion was widely excised. Shortly after surgery, the patient was lost to follow-up, Mi croscopic examination of the specimen showed it to be a pseudoencapsul ated mass composed of cellular aggregates that, at their periphery, co nsisted of numerous large, vesicular, hyperchromatic, proliferating ba saloid cells with scarce cytoplasm (Fig. 2). Centrally it was composed of keratotic material and shadow or ghost cells, and pale eosinophili c keratinocytes (Fig. 3). The cellular islands were surrounded by a de nse inflammatory infiltrate in some areas. We could not find any infil tration into fat lobules or other underlying structures. Some small ce llular aggregates resembled, morphologically, primitive hair germs sug gesting a hair follicle origin (Fig. 4). Slight pleomorphism and multi ple mitoses were present, as many as 10/high power field (Fig. 5). A d iagnosis of malignant pilomatricoma was made.