Diaphragmatic hernia in elderly: An unusual cause of secondary polycythemia.

Polycythemia vera (PV) is a myeloproliferative neoplasm classically characterized by erythrocytosis associated with a high risk of thromboembolic events. Chronic pulmonary hypoxia is one of the most common causes of secondary polycythemia. We present a rare case of a 72-year-old elderly male patient who presented with generalized body weakness and recurrent cough with expectoration for 15 years. Investigation showed raised hemoglobin, hematocrit, and serum erythropoietin levels. Contrast-Enhanced Computed Tomography (CECT) of the thorax revealed a defect in the left hemidiaphragm of size 5.7 cm containing the stomach, pancreatic body, and colon as content, causing contralateral mediastinal shift with loss of lung volume. He was managed with therapeutic phlebotomy and reported significant improvement in fatigue. The significant loss of lung volume due to the diaphragmatic hernias evidenced by the CECT thorax, was postulated as the cause of secondary polycythemia in our case. The case highlights the rare presentation of congenital diaphragmatic hernia late in the elderly and the importance of its early diagnosis to prevent complications like recurrent respiratory infection and secondary polycythemia.