Small cell neuroendocrine carcinoma of the paranasal sinus
A 22-year-old female was referred to our center with a complaint of painless swelling on the left side of the face for 6 weeks duration. Extra-oral examination revealed the presence of an expansile swelling in the left maxillary region, extending into the peri-orbital region. There was stretching of the skin on the left face over the swelling. On intra-oral examination, a proliferative growth was noted in the left maxillary gingivo-buccal sulcus extending downwards till the level of the oral commissure [Figure and ]. Computerized tomography (CT) scan demonstrated a large destructive soft tissue lesion in the left maxillary sinus with extensions into the left nasal cavity, ethmoid and sphenoid sinus, left alveolus, and hard palate. Extensions were also noted into the infra temporal fossa, soft tissues of the cheek, masticator spaces, and the inferior orbital fissure [Figure and ]. An intra-oral biopsy of the lesion was done which on microscopy revealed a poorly differentiated neoplasm composed of monotonous sheets of small round blue cells with scanty cytoplasm and hyperchromatic nuclei, the cells were arranged in a rosettoid manner. The tumor cells were seen infiltrating the fibrocollagenous connective tissue with areas of necrosis; the mitotic activity was not clearly made out. Immunohistochemical profile showed tumor cell positivity for Epithelial Membrane Antigen (EMA), keratin, Neuron Specific Enolase (NSE), chromogranin, synaptophysin, and CD 57. The tumor cells were negative for vimentin, desmin, Leukocyte Common Antigen (LCA), CD 99, Human Melanoma Black (HMB 45), and Thyroid Transcription Factor-1 (TTF1). The tumor cells that showed strong nuclear positivity to Ki 67 was 50%. The final histopathology on immunohistochemistry correlation [Figures - and -] favored a diagnosis of SNEC. CT scan of the brain, thorax, and abdomen were normal. A bone marrow aspiration and biopsy did not show any atypical cells.\nA combination of concurrent chemotherapy and radiotherapy was planned. The patient received a total of 60 Grey of external beam radiotherapy along with four cycles of concurrent cisplatin and etoposide. There was a clinical complete response, a post-therapy CT scan (after 6 months) showed only residual thickening of the left maxillary antrum. The patient did not wish to undergo any further investigations/biopsy to confirm remission; she is being followed up with a combination of clinical examination and imaging and is presently symptom-free with no evidence of recurrence for close to 2 years now [Figures and ].