Intrathoracic tumor of the chest wall: A case of Castleman's disease mimicking myositis of the lower extremities.

Castleman's disease refers to a group of uncommon lymphoproliferative disorders which exhibit common lymph-node histological features. A 72-year-old male patient presented with signs of lower limb myositis. Detailed work-up focused initially on evaluating hematological malignancies, the presence of a solid tumor, autoimmune diseases and degenerative disorders of the peripheral nerves. Finally, a PET-CT scan was performed to exclude paraneoplastic manifestations of a primary tumor, revealing  however a tumor of the thoracic wall. The definite histological diagnosis confirmed the presence of unicentric Castleman's disease of the chest wall. The manifestations of the present case suggest that a systemic inflammation might occur in the unicentric form of the disease possibly due to cytokine hypersecretion. The unicentric manifestation of the disease should be well distinguished from the multicentric appearance. Unicentric disease is a surgical condition and warrants a follow-up based on the systemic inflammation that might occur.