title: Sinonasal small round blue cell tumors: An approach to diagnosis.
abstract: The differential diagnosis for small round cell tumors in the sinonasal tract is diverse and as the body of literature documenting not only uncommon presentations but also availability of ancillary studies grows, so does the need for a reminder to take a conservative and thorough approach before rendering a diagnosis. Small tissue samples are particularly problematic, with limitations that include volume of tumor cells available for studies, lack of architectural context and a non-specific gross description. Incorporation of patient history and presentation, radiologic findings, clinical impression and concurrent studies often guide the course of studies performed by the pathologist. If these are non-specific, the pathologist may need to perform ancillary studies, including a broad panel of immunohistochemical stains and molecular studies. If tissue is limited, a precise classification may not be achievable. Although the expectation to render a definitive diagnosis is high, the pathologist should never feel compelled to go further with a diagnosis than the tissue itself supports.
authors.affiliation: Moffitt Cancer Center, Tampa, Florida.
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Simons
authors.affiliation: Departments of Pathology, Pediatrics and Orthopedic Surgery, Nebraska Medical Center, Omaha, Nebraska.
authors.forename: Julia A
authors.initials: JA
authors.lastname: Bridge
authors.affiliation: Moffitt Cancer Center, Tampa, Florida; Department of Anatomic Pathology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida; Department of Oncologic Sciences, Morsani College of Medicine, University of South Florida, Tampa, Florida; Department of Pathology & Cell Biology, Morsani College of Medicine, University of South Florida, Tampa, Florida. Electronic address: Marino.Leon@Moffitt.org.
authors.forename: Marino E
authors.initials: ME
authors.lastname: Leon
mesh_terms: D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D009296:Nasal Cavity / Q000737:chemistry / Q000473:pathology*; D018329:Nevus, Blue / Q000737:chemistry / Q000145:classification / Q000473:pathology*; D009669:Nose Neoplasms / Q000737:chemistry / Q000145:classification / Q000473:pathology*; D010255:Paranasal Sinus Neoplasms / Q000737:chemistry / Q000145:classification / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012878:Skin Neoplasms / Q000737:chemistry / Q000145:classification / Q000473:pathology*
keywords: Adenoid cystic carcinoma; Basaloid squamous cell carcinoma; Ewing sarcoma/peripheral primitive neuroectodermal tumor; Lymphoepithelial carcinoma; Malignant mucosal melanoma; NUT midline carcinoma; Nasal cavity; Non-keratinizing squamous cell carcinoma; Olfactory neuroblastoma; Rhabdomyosarcoma and synovial sarcoma; Sinonasal; Sinonasal undifferentiated carcinoma; Small cell carcinoma, neuroendocrine type; Small round cell tumor; fluorescent in situ hybridization; immunohistochemistry