Ultrastructural diagnosis of a plexiform liposarcoma

Abstract

Less well differentiated malignant neoplasms may pose a serious problem in the establishment of a definitive diagnosis at the light microscopy level. In such instances, transmission electron microscopy (TEM) may prove to be of value as it may identify diagnostic characteristics that can be appreciated only at ultrastructural magnification. The case reported here illustrates the application of TEM in the differential diagnosis of a soft tissue sarcoma.A 63 year old male presented in the out patient service with a mass in the region of the left scapula. Its gross appearance was likened to that of a "Big Mac." A needle biopsy was performed and submitted for histological and TEM examination. Histology of multiple serial sections showed the presence of a malignant neoplasm composed of markedly pleomorphic cells, including numerous bizarre giant cells and smaller cells with irregular nuclear outline and indistinct eosinophilic cytoplasm. Cytoplasmic vacuoles were prominent. They did not stain with PAS nor mucin stains.