Mb. Morgan et al., ANGIOMATOID MALIGNANT FIBROUS HISTIOCYTOMA REVISITED - AN IMMUNOHISTOCHEMICAL AND DNA-PLOIDY ANALYSIS, The American journal of dermatopathology, 19(3), 1997, pp. 223-227
A histologic, immunohistochemical, and DNA ploidy analyses were perfor
med on two cases of angiomatoid malignant fibrous histiocytoma to asce
rtain the histogenesis and relationship of endothelial, histiocytic, a
nd fibroblastic elements. Both cases were slowly growing, grossly enca
psulated, subcutaneous masses resected from pediatric patients. Micros
copically, the tumors were composed of solid masses of epithelioid and
spindle cells with abnormal endothelial-lined and blood-filled cystic
spaces surrounded by normal vascular structures and aggregates of lym
phocytes occasionally forming germinal follicles. The tumor cells stai
ned exclusively with CD34 and vimentin antibodies. Tumor-associated ve
ssels stained for CD31, CD34, vimentin, and Ulex europaeus. Occasional
cells within germinal follicles stained for lysozyme, CD68, and HAM56
. Ploidy analysis of tumor cells showed intermediate aneuploidy with a
DNA index of 1.14. Blood vessels within and surrounding the tumor as
well as inflammatory cells were DNA euploid. These studies suggest tha
t the tumor-though comprised of histologically and immunohistochemical
ly benign-appearing euploid endothelial, fibroblastic, and inflammator
y elements-contains an aneuploid population of undifferentiated mesenc
hymal cells.