title: Microcystic/Reticular Schwannoma Arising in the Submandibular Gland: A Rare Benign Entity that Mimics More Common Salivary Gland Carcinomas.
abstract: Microcystic/reticular schwannoma is a recently described variant of schwannoma with a predilection for the gastrointestinal tract, rarely involving the head/neck region. This is the first reported case involving the submandibular gland. We present a case in a 34 year old man with 4.5 cm submandibular mass. Fine needle aspiration suggested a spindle cell lesion. Frozen section evaluation raised the possibility of mucoepidermoid carcinoma. Resection showed a well circumscribed mass with a mucoid appearance. Histologic findings include a lobular architecture with fibrous septa, a lympho-plasmacytic infiltrate, and scattered lymphoid aggregates at the periphery. There are two distinct histologic patterns with solid areas of spindle cells and areas of spindle/ovoid cells with a microcystic pattern in a myxoid background. The tumor has a pushing border, with extension into adipose and adjacent parenchyma, without cytologic atypia or necrosis. Immunohistochemical stains are positive for S-100 and CD34, and negative for calponin, mammoglobin, ALK1, p63, ER, GFAP, SMA, desmin, cytokeratin 7, cytokeratin AE1/AE3, and C-Kit. Mucicarmine stain is negative. Recognition of this benign unusual variant of schwannoma is paramount for appropriate conservative treatment due to the morphologic and immunohistochemical overlap with primary salivary gland carcinomas.
authors.affiliation: Department of Pathology, New York University School of Medicine, 462 1st Avenue, Office 4W35, New York, NY, 10016, USA. Ryan.Lau@nyumc.org.
authors.forename: Ryan P
authors.identifier: http://orcid.org/0000-0003-2155-0346
authors.initials: RP
authors.lastname: Lau
authors.affiliation: Department of Pathology, New York University School of Medicine, 462 1st Avenue, Office 4W35, New York, NY, 10016, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Melamed
authors.affiliation: Department of Pathology, New York University School of Medicine, 462 1st Avenue, Office 4W35, New York, NY, 10016, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Yee-Chang
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, New York University School of Medicine, 462 First Avenue, Suite 5SE5, New York, NY, 10016, USA.
authors.forename: Sonya
authors.initials: S
authors.lastname: Marcus
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, New York University School of Medicine, 462 First Avenue, Suite 5SE5, New York, NY, 10016, USA.
authors.forename: Babak
authors.initials: B
authors.lastname: Givi
authors.affiliation: Department of Pathology, New York University School of Medicine, 462 1st Avenue, Office 4W35, New York, NY, 10016, USA.
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Zamuco
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009442:Neurilemmoma / Q000473:pathology*; D013365:Submandibular Gland Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: Microcystic schwannoma; Reticular schwannoma; Salivary gland; Schwannoma; Submandibular gland