Paraneoplastic Aquagenic Pruritus: A Case of Pancreatic Cancer

Paraneoplastic pruritus has been reported mostly in association with haematological malignancies, and rarely with solid tumours. Aquagenic pruritus is itching without any skin lesion that develops a few minutes after contact with water of any temperature and it is associated with polycythaemia vera or other lymphoproliferative diseases. Here we report a case of a previously healthy 78-year-old Portuguese woman, who had been treated unsuccessfully for aquagenic pruritus for the previous eight months, and presented to the emergency department complaining of pain and swelling in her left leg. Deep vein thrombosis was diagnosed and oral anticoagulation was initiated. Blood tests revealed a normal blood count and normal liver enzymes, except for alkaline phosphatase and lactate dehydrogenase levels, which were slightly elevated. Hypercobalaminaemia and folic acid deficiency were also noted. JAK2 V617F/12 exon mutation was not present. Thoracic, abdominal and pelvic computed tomography revealed a locally advanced pancreatic tumour. Ultrasound-guided fine-needle aspiration cytology of the lesion revealed a moderately differentiated adenocarcinoma of pancreatic ductal origin. Tumour marker assays showed elevation of both carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). Aquagenic pruritus should be thoroughly investigated to exclude a neoplastic disease, especially if treatment is refractory or if another paraneoplastic syndrome is present. Although aquagenic pruritus is more commonly associated with haematological malignancies than solid tumours, a rare case of aquagenic pruritus is described here as a paraneoplastic syndrome of pancreatic cancer. To the best of our knowledge, this is the first case of pancreatic cancer that presented with aquagenic pruritus and dual paraneoplastic syndromes.