title: Sclerosing rhabdomyosarcoma presenting in the masseter muscle: a case report.
abstract: Sclerosing rhabdomyosarcoma (SRMS) is exceedingly rare, and may cause a great diagnostic confusion. Histologically, it is characterized by abundant extracellular hyalinized matrix mimicking primitive chondroid or osteoid tissue. So, it may be easily misdiagnosed as chondrosarcoma, osteosarcoma, angiosarcoma and so on. Herein, we report a case of SRMS occurring in the masseter muscle in a 40-year-old male. The tumor showed a diverse histological pattern. The tumor cells were arranged into nests, cords, pseudovascular, adenoid, microalveoli and even single-file arrays. Immunostaining showed that the tumor was positive for the Vimentin, Desmin and MyoD1, and was negative for CK, P63, NSE, CD45, CD30, S-100, CD99, Myoglobin, CD68, CD34, CD31, and α-SMA. Based on the morphological finding and immunostaining, it was diagnosed as a SRMS. In addition, focally, our case also displayed a cribriform pattern resembling adenoid cystic carcinoma. This may represent a new histological feature which can broaden the histological spectrum of this tumor and also may lead to diagnostic confusion.
  The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1615846455818924.
authors: Department of Pathology, the First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang 110001, China.
authors: Xu-Yong
authors: XY
authors: Lin
authors: Yan
authors: Y
authors: Wang
authors: Juan-Han
authors: JH
authors: Yu
authors: Yang
authors: Y
authors: Liu
authors: Liang
authors: L
authors: Wang
authors: Qing-Chang
authors: QC
authors: Li
authors: En-Hua
authors: EH
authors: Wang
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D003937:Diagnosis, Differential; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D008406:Masseter Muscle / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D019042:Muscle Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D012208:Rhabdomyosarcoma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D012598:Sclerosis
chemical_list: D014408:Biomarkers, Tumor
references: Diagn Pathol. 2010 Aug 11;5:52
references: 20701800
references: Diagn Pathol. 2012 Aug 28;7:112
references: 22925697
references: Diagn Pathol. 2007 Jul 02;2:23
references: 17601346
references: Hum Pathol. 2009 Sep;40(9):1347-52
references: 19454362
references: Virchows Arch. 1999 Apr;434(4):351-3
references: 10335946
references: Diagn Pathol. 2010 Aug 05;5:51
references: 20687934
references: Pediatr Dev Pathol. 2004 Jul-Aug;7(4):391-6
references: 15383934
references: Int J Surg Pathol. 2006 Jul;14(3):193-9
references: 16959698
references: Int J Surg Pathol. 2010 Oct;18(5):394-7
references: 19017660
references: Diagn Pathol. 2012 Sep 21;7:125
references: 22999069
references: Am J Surg Pathol. 2002 Sep;26(9):1175-83
references: 12218574
references: Anticancer Res. 2008 Jul-Aug;28(4C):2361-7
references: 18751419
references: Am J Clin Pathol. 2008 Mar;129(3):410-5
references: 18285263
references: Head Neck Pathol. 2013 Jun;7(2):193-202
references: 22990679
references: Virchows Arch. 2005 Jan;446(1):64-7
references: 15660283
references: Virchows Arch. 2006 Nov;449(5):572-8
references: 17016719
references: Diagn Pathol. 2012 Sep 03;7:118
references: 22943673
references: Pediatr Dev Pathol. 2004 Nov-Dec;7(6):583-94
references: 15630526
references: Diagn Pathol. 2011 Dec 30;6:130
references: 22208720
references: Ann Diagn Pathol. 2009 Oct;13(5):334-8
references: 19751910
references: Diagn Cytopathol. 2010 Oct;38(10):761-4
references: 20091893
references: Virchows Arch. 2000 Apr;436(4):305-11
references: 10834531
references: Laryngoscope. 2005 Jan;115(1):48-50
references: 15630365