A 30-year-old male, carpenter by profession, presented with a history of dry cough and progressive shortness of breath for two months along with right-sided chest pain for one and a half months. The clinico-radiological picture was suggestive of right-sided massive pleural effusion. Computed tomography (CT) scan of the thorax showed a huge mediastinal mass occupying the entire right hemithorax with very small amount of pleural effusion. CT-guided fine needle aspiration cytology and tru-cut biopsy from the mass both revealed small round-cell tumour, possibly small cell carcinoma of the lung. However, on immunohistochemistry tumour cells expressed Mic-2 and it was consistent with a diagnosis of primitive neuroectodermal tumour.

A 70-years-old male presented with blackening of both hands and face for last six months which was progressive and attended dermatology outpatients department. Dermatologist opined the skin lesions as acanthosis nigricans. He was referred to our department to evaluate for any underlying internal malignancy as he was a smoker. His chest X-ray revealed right sided hilar prominence with a mid zone cavity with fluid level. Fibreoptic bronchoscopy was done, there was one ulcerative growth in right middle lobe bronchus. Biopsy from the ulcer revealed probable squamous cell carcinoma. CT scan of thorax was also done and CT guided FNAC of Rt lung lesion yielded non small cell carcinoma. His skin lesions were also biopsied and diagnosis of acanthosis nigricans was confirmed. Here we report a case of acanthosis nigricans associated with non-small cell cancer of lung.

Congenital abnormalities of lung are very rare entity, and very often under or misdiagnosed by physicians. The present case, a 12-year boy, who was initially diagnosed as unilateral massive pleural effusion with collapse of lung, and after thorough investigation, including CT scan of thorax, fiber-optic bronchoscopy, and echocardiography, a final diagnosis of unilateral lung hypoplasia was made. So if a teenager present with a unilateral opaque hemithorax in chest X-ray, this entity may be a differential diagnosis.