Pseudomesotheliomatous Type of Sarcomatoid Squamous Cell Lung Cancer Presenting With Hemothorax

A 44-year-old man presented with spontaneous massive hemothorax. Computed tomographic scan revealed thickened and nodular pleura with no evidence of lung tumor. The patient underwent right open total pleurectomy. Histopathologic and immunohistochemical studies of the pleura confirmed poorly differentiated sarcomatoid squamous cell carcinoma of the lung with metastasis to the pleura. The carcinoma was psuedomesothelimatous type because of its presentation as diffuse pleural thickening. This presentation of sarcomatoid cancer as pseudomesotheliomatous type with massive hemothorax is rare and can be considered as a differential diagnosis in diffuse pleural thickening or hemothorax, especially in the absence of a clinically identifiable primary lung tumor.