Pleural mesothelioma: an unusual case diagnosed on pleural fluid cytology and immunocytochemistry.

Mesothelioma is a rare neoplasm with relationship to occupational and environmental exposure to asbestos. Its accurate and early diagnosis is often difficult. We present an unusual clinical presentation and diagnostic dilemma in a 30-year-male, who presented with neck pain and diffuse edema of left upper limb. The color Doppler ultrasound revealed venous thrombosis. The right supraclavicular lymph node biopsy revealed a poorly differentiated carcinoma. The patient had mild bilateral pleural effusion, the characteristic cytomorphological features of mesothelioma on fluid cytology were helpful in establishing the diagnosis.