title: Pseudoangiosarcomatous features in medullary thyroid carcinoma spindle-cell variant. Report of a case studied by FNA and immunohistochemistry.
abstract: We report a case of medullary thyroid carcinoma (MTC), spindle cell variant, which exhibited striking histological pseudovascular clefts and abortive lumina, closely mimicking an angiosarcoma. The patient is a 72-yr-old-man who presented facial rash and a solid nodule in the right lobe of the thyroid gland. The fine-needle aspiration (FNA) showed bloody background containing loosely groups of fusiform and plasmocytoid cells with coarse chromatin and eosinophilic granular cytoplasms. Microscopically, the tumor exhibited spindle-cell pattern intermingled with a striking angiosarcoma-like pattern characterized by the presence of abortive lumen and clefts containing erythrocytes. Dense hyaline extracellular amyloid was present. The tumor cells were strongly positive for cytokeratin, chromogranine-A, synaptophysine, serotonin, calcitonin, and CEA. TTF-1 was weakly positive. Stains for CD34 and CD31 were negative. This case illustrates that the spindle cell variant of MTC may exhibit an infrequent angiosarcoma-like appearance which may be misdiagnosed as angiosarcoma.
authors.affiliation: Department of Pathology, Hospital Marina Alta, Denia, Alicante, Spain. laforga_jua@gva.es
authors.forename: Juan B
authors.initials: JB
authors.lastname: Laforga
authors.forename: F Ignacio
authors.initials: FI
authors.lastname: Aranda
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D044963:Biopsy, Fine-Needle; D018276:Carcinoma, Medullary / Q000473:pathology*; D003937:Diagnosis, Differential; D006394:Hemangiosarcoma / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor