title: Primary sinonasal mucosal melanoma with aberrant diffuse and strong desmin reactivity: a potential diagnostic pitfall!
abstract: The broad morphologic spectrum, inherent immunophenotypic heterogeneity of malignant melanoma and its rarity in the sinonasal tract are major challenges in eliciting the correct diagnosis, which may lead to misclassification and inadequate medical management. Herein, we describe a single case of a 70 year-old male with sinonasal mucosal melanoma, exhibiting varying histologic phenotypes including small round blue cell morphology, epithelioid and focal rhabdoid morphology and strong, diffuse desmin immunoreactivity. These constellation of features initially prompted the diagnosis of rhabdomyosarcoma. The differential diagnosis in this anatomic area includes other malignant small round blue cell tumors of the sinonasal mucosa such as rhabdomyosarcoma, olfactory neuroblastoma, sinonasal undifferentiated carcinoma, and lymphoma. We reviewed precedent literature and further discuss the potential pitfalls to which pathologists may be prone.
authors: Department of Pathology and Laboratory Medicine, Wexner Medical Center at The Ohio State University, 410 West 10th Avenue, Columbus, OH, 43210, USA.
authors: Stephen M
authors: SM
authors: Smith
authors: Alessandra C
authors: AC
authors: Schmitt
authors: Ricardo L
authors: RL
authors: Carrau
authors: O Hans
authors: OH
authors: Iwenofu
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D003893:Desmin / Q000096:biosynthesis; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000175:diagnosis*; D010255:Paranasal Sinus Neoplasms / Q000175:diagnosis*; D012208:Rhabdomyosarcoma / Q000175:diagnosis; D013101:Sphenoid Sinus / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D003893:Desmin