Undifferentiated pleomorphic sarcoma

CLINICAL FEATURES A 42-year-old female patient presented a painless, firm mass on the hard palate involving the premaxilla region. The swelling was small in size initially which grew progressively to a size of 2 × 3 cm in a duration of 3 months. HISTOPATHOLOGY The section showed orthokeratinized stratified squamous epithelium in association with connective tissue exhibiting aggregates of spindle-shaped fibroblast-like cells streaming in interlacing fascicles and intersecting with cells from adjacent aggregates giving a storiform pattern, in 10× magnification [Figure 1]. Connective tissue exhibits numerous aggregates of streaming interlacing fascicles at various foci of the section, in 10× magnification [Figure 2]. Intersecting fascicles of plump spindle-shaped fibroblast-like cells exhibiting pleomorphism and hyperchromatism, in 40× magnification [Figure 3]. The spindle-shaped cells show marked hyperchromatism, nuclear pleomorphism, and increased mitotic activity, under 40× magnification [Figure 4]. Areas of hemorrhage and necrosis were found amidst the malignant connective tissue cells, under 10× magnification [Figure 5]. Immunohistochemistry was done with markers vimentin and CD68. Malignant cells showed strong positivity for vimentin and moderate positivity for CD68, as shown in Figures 6 and 7, respectively. Figure 1: Orthokeratinized stratified squamous surface epithelium and connective tissue shows bundles of spindle-shaped cells in a storiform pattern (10× magnification)Figure 2: Field showing interlacing fascicles of spindle-shaped cellsFigure 3: Malignant cells exhibiting pleomorphism and hyperchromatism (40× magnification)Figure 4: Plump spindle-shaped fibroblasts and increased mitosis (40× magnification)Figure 5: Areas of hemorrhage and necrosis were found amidst the malignant connective tissue cellsFigure 6: Immunohistochemical picture showing strong positivity for vimentinFigure 7: Immunohistochemical picture showing moderate positivity for CD 68DIAGNOSIS Undifferentiated pleomorphic sarcoma (malignant fibrous histiocytoma). CONCLUSION Storiform variant malignant fibrous histiocytoma mimics all poorly differentiated malignancies, and is identified by using immunohistochemical markers. ACKNOWLEDGMENT We thank Dr. Prathiba Ramani, MDS, Professor, Oral and Maxillofacial Pathology, Saveetha Dental College and Hospitals.