SMARCB‐1 deficient squamous cell carcinoma of a mediastinal cyst

Abstract

SMARCB1-deficiency has been found in a variety of tumors. Here, we report a SMARCB1-deficient squamous cell carcinoma of a mediastinal cyst. A 53-year-old man was diagnosed with a cyst of the pericardial region in his twenties. As a symptom at this time, he complained of severe pain and dyspnea in the right chest. Following investigation using imaging and histological examination of the biopsy specimen, he was diagnosed with a SMARCB1 deficient malignant neoplasm. As tumor cells showed positive immunostaining for p40 and CK5/6, the immunophenotype of the tumor was consistent with squamous cell carcinoma (SCC). The patient died six months after initial presentation. The autopsy showed the most part of the tumor with anaplastic cytomorphology, loss of SMARCB1, diffusely positive immunostaining for pancytokeratin, and negative immunostaining for p40 and CK5/6. To our knowledge, this is the first report of SMARCB1-deficient SCC of mediastinal cyst.

SMARCB1 (INI‐1) and NUT immunoexpression in a large series of head and neck carcinomas in a Brazilian reference center

“…Moreover, in view of our findings, it seems clear that the EBV does not seem to play an important role on the pathogenesis of these tumors. On the other hand, it is known that the SDSCs 1-4 and SMARCB1 (INI-1)-deficient carcinomas in extrasinonasal locations [8][9][10] are tumors highly aggressive, with short survival. In the current series, two patients with SMARCB1 (INI-1)-deficient carcinoma died of the disease.…”

“…The prototypical SMARCB1 (INI-1)-deficient tumor is the malignant rhabdoid tumor, and through the use of immunohistochemistry, an increasing number of SMARCB1 (INI-1)-deficient tumors have been described, including, among others, sinonasal carcinomas. 1,[8][9][10] Nuclear protein in testis (NUT) carcinoma is a rare and aggressive poorly differentiated carcinoma, often affecting the head and neck region (especially the nasal cavity and paranasal sinuses). 4 SDSCs are characterized by presenting a basaloid, plasmacytoid/rhabdoid, [1][2][3] or oncocytoid/ adenocarcinoma-like 4 histopathological pattern.…”

“…7 Noteworthy, SMARCB1 (INI-1)-deficient carcinomas in extrasinonasal location are extremely rare. 1,[8][9][10] Nuclear protein in testis (NUT) carcinoma is a rare and aggressive poorly differentiated carcinoma, often affecting the head and neck region (especially the nasal cavity and paranasal sinuses). 11,12 To date, approximately 51 head and neck NUT carcinomas have been reported.…”