Endocrine Abstracts

Objective: Highlight hypertrophic pulmonary osteoarthropathy (HPOA) and partial HPOA as a cause for raised bony alkaline phosphatase (ALP).

Case: We report the case of a 59-year-old lady who was referred to the endocrine clinic with 2 years history of bilateral leg pain and raised bony ALP. She denied any other symptoms. She had no past medical history. She was not on any regular medications and she has never smoked. Apart from mild tenderness over both legs, examination was unremarkable with no evidence of clubbing.

Investigations: A bone scan showed low grade linear increased tracer activity along the outer border of both tibias. X-rays showed bilateral, symmetrical, periosteal reaction along the distal tibia raising the possibility of HPOA. A CXR showed a large mass at the left base. CT thorax showed that this is a 10×7 cm bilobed soft tissue mass pleurally based in the left lower chest which was felt to be a pleural fibroma. A PET scan showed low grade uptake in the mass and there was no evidence of disease in any other site.

Management: The patient underwent left thoracotomy with resection of the mass. Histology confirmed a diagnosis of benign solitary fibrous tumor of the pleura (SFTP).

Post-operatively, her leg pain resolved with normalization of alkaline phosphatase level within 2 months of surgery.

Conclusion: Hypertrophic pulmonary osteoarthropathy, especially periostitis without clubbing (Partial HPOA), may go unrecognized. A raised bony alkaline phosphatase can be the only early abnormality that leads to the diagnosis of the cause of secondary HPOA. Including HPOA (or partial HPOA as in our case) in the differential diagnosis list when assessing a patient with raised bony alkaline phosphatase is very important especially as timely intervention can be crucial for effective management of secondary causes.