Small cell carcinoma of the pyriform sinus successfully treated with concurrent chemo-radiotherapy: A case report

Abstract

Background: Primary small cell carcinomas (SCCs) are uncommon in extrapulmonary sites and account for only 2.5% to 5.0% of all SCCs. SCCs in the pyriform sinus are rare and there is little information regarding this disease, especially on therapeutics. Herein, we present a case of successfully treated SCC in the right pyriform sinus that occurred in a patient with small cell lung carcinoma (SCLC) that completely resolved 4 years prior.

Methods: A 1.5 × 1.5-cm mass in the right pyriform sinus was detected on imaging studies in a 71-year-old male at a regular check-up visit after being in remission from SCLC.

Results: Based on histologic examination and immunohistochemistry, the tumor in the right pyriform sinus was diagnosed as an extrapulmonary SCC. Chemo-radiotherapy was applied to the SCC of the pyriform sinus with a regimen of etoposide and cisplatin. The patient exhibited complete response to treatment and has been disease free for 11 months.

Conclusion: This interesting case shows that chemotherapy with concurrent radiation may be an effective therapeutic modality for localized extrapulmonary SCC similar to localized SCLC, which is treated with concurrent chemo-radiotherapy as the standard therapeutic option.

Figure 1

(A) Postenhancement axial CT scan of the head and neck reveals a heterogeneously enhancing 1.5 × 1.5-cm-sized mass (arrows) in the right pyriform sinus of the hypopharynx. (B) FDG PET-CT scan displays elevated glucose metabolism (maximum standardized uptake value = 29.28). (C) Arterial phase coronal image of whole body FDG-PET scan highlights elevated glucose metabolism (arrow) in the neck and no evident SCLC. (D) H&E staining (×100) shows the highly cellular component of the pyriform sinus mass. (E) High-power field examination (×400) of the specimen demonstrates dense sheets of small cells with a high nuclear-to-cytoplasm ratio, hyperchromasia, nuclear molding, and high mitotic count. (F) Immunohistochemistry (×400) was positive for CD56. Brown-stained cells were considered to express CD56 as shown in inset image. (G) Immunohistochemistry (×400) was negative for thyroid transcription factor-1. (H) Postenhancement axial CT scan of the head and neck shows no evidence of tumor after chemoradiotherapy. (I) FDG PET-CT scan displays absence of increased metabolism after treatment. (J) Arterial phase coronal image of whole body FDG-PET scan exhibits no hypermetabolic lesions in the neck or chest on follow-up scan. CT = computed tomography, FDG = 2-deoxy-2-[18F]-fluoro-d-glucose, H&E = hematoxylin and eosin, PET = positron emission tomography, SCLC = small cell lung carcinoma.