Malignant proliferating tricholemmal tumor: report of three cases

Abstract

We report three cases of malignant proliferating tricholemmal tumors, two of which displayed rapid growth of long-standing scalp nodules. The third case was a nodule on the scapula with axillary lymph node metastasis. Although some investigators believe that the diagnosis of malignancy is certain only with evidence of metastasis; in our first two cases morphologic features suggested malignancy which included infiltration of adjacent tissues, high degree of cytologic atypia, abundant dyskeratotic cells, monstrous multinucleated cells and atypical mitotic figures. We emphasize the possibility of malignancy in long-standing proliferating tricholemmal tumors that show rapid enlargement. (C) 1997 Elsevier Science B.V.