An Elusive Case of Pleural Effusion

The incidence of distant metastasis in head and neck Squamous Cell Carcinoma (SCC) is relatively low. The most frequently involved sites for distant metastasis are lungs, followed by bone and liver. The most important predictive factors for distant metastasis appear to be site of the primary tumour (hypopharynx), advanced T&N classification, locoregional control and histologic grade. A 61-year-old male, chronic smoker, presented with complaints of Grade 4 mMRC (Modified Medical Research Council) dyspnoea. He had left-sided buccal mucosal SCC (locally advanced) and was on palliative chemotherapy. He had undergone treatment for pulmonary tuberculosis seven years back. He was tachypneic and clinical examination revealed absent breath sounds in the left hemithorax. Chest radiograph showed a massive left pleural effusion which was found to be exudative after therapeutic thoracocentesis. Cytology tests were negative for malignant cells. Positron Emission Tomography (PET) scan showed uptake along the left pleura (SUV Max-5.06) and left buccal mucosa (SUV Max -4.1). Thoracoscopic frozen section pleural biopsy revealed metastatic squamous cell carcinomatous deposits in the pleura. On table pleurodesis was done with doxycycline. The patient was continued on palliation with no recurrent effusion. However, he succumbed to the disease after four months. This case report describes a rare case of malignant pleural effusion from a primary buccal mucosal SCC without any concurrent lung involvement.