IJCEP Copyright © 2007-All rights reserved.
Int J Clin Exp Pathol 2012;5(3):264-269

Case Report
Primary small cell carcinoma of the maxillary sinus: a case report with
immunohistochemical and molecular genetic study involving KIT and PDGFRA

Tadashi Terada

Departments of Pathology, Shizuoka City Shimizu Hospital, Shizuoka, Japan

Received October 24, 2011; accepted February 15, 2012; Epub March 25, 2012; Published March 30, 2012

Abstract: Primary small cell carcinoma of the nose and paranasal sinuses is very rare; only a few reports are present in the English literature.
The author herein reports a very rare case of primary small cell carcinoma of the maxillary sinus with an emphasis on immunohistochemistry
and on KIT and PDGFRA. A 64-year-old man was admitted to our hospital because of left nasal obstruction. Endoscopy revealed three nasal
polyps, and imaging modalities revealed an infiltrative tumor (45 x 45 mm) in the left maxillary sinus with invasion into nasal cavity. Multiple
biopsies are taken from the nasal lesions. Histologically, the tumor consists of proliferation of malignant small epithelioid cells with
hyperchromatic nuclei, fine chromatin, scant cytoplasm, molded nuclei, and absent nucleoli. Immunohistochemically, the malignant cells were
positive for cytokeratin (CK) 18, synaptophysin, CD56, p53, Ki-67 (labeling=95%), bcl-2, KIT, and PDGFRA. However, they were negative for
pancytokeratins, high molecular weight CK, CK5/6, CK7, CK 14, CK 19, CK20, vimentin, neuron-specific enolase, chromogranin, CD15, CD45,
S100 protein, CEA, CA19-9, glial fibrillary acidic protein, neurofilaments, neuroblastoma, CD99, surfactant apoprotein A, melanosome, and
TTF-1. The pathologic diagnosis was small cell carcinoma. A molecular genetic analysis using PCR-direct sequencing was performed using
paraffin sections, and it showed no mutations of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) genes. Imaging modalities
including CT, MRI and PET did not reveal any tumors, including the lung, other than the maxillary sinus tumor. The present case is the first of
small cell carcinoma of the maxillary sinus with a comprehensive immunohistochemical examination and a gene analysis of KIT and PDGFRA.

Keywords: Small cell carcinoma, maxillary sinus, immunohistochemistry, KIT, PDGFRA

Address all correspondence to:
Dr. Tadashi Terada
Department of Pathology, Shizuoka City Shimizu Hospital
Miyakami 1231 Shimizu-Ku, Shizuoka 424-8636, Japan.
Tel: 81-54-336-1111; Fax: 81-54-336-1315
E-mail: piyo0111jp@yahoo.co.jp