Chronic non-cirrhotic portal vein thrombosis with mild protein C deficiency and splenomegaly: an uncommon aetiology underlying long standing thrombocytopenia

Chronic portal vein thrombosis (PVT) is a rare and diagnostically challenging cause of thrombocytopenia in young individuals. This case report describes a young woman with a history of unexplained thrombocytopenia for more than five years. She was initially managed for primary immune thrombocytopenic purpura. She later presented with frank haematemesis and was found to have splenomegaly, oesophago-gastric varices, and chronic non-cirrhotic PVT, likely due to an underlying Protein C deficiency. This case highlights the challenges faced in establishing an accurate aetiological diagnosis for thrombocytopenia in young patients, and emphasises the importance of continuous monitoring, as well as comprehensive and multidisciplinary evaluation.