Anti-tumour necrosis factor-α-induced lupus in a patient receiving infliximab for sarcoidosis.

Infliximab is a chimeric monoclonal antibody against tumour necrosis factor (TNF)-α, with a wide variety of uses. Monoclonal antibody therapies specifically targeting TNF-α, have emerged as a novel treatment option for patients with refractory sarcoidosis, with infliximab being the most widely used. This is not true of other TNF-α inhibitors, for example etanercept, which have a different mechanism of action, and are not effective in sarcoidosis.

A challenging diagnosis of malignant mesothelioma with osteosarcomatous differentiation metastasizing to bone.

Malignant pleural mesothelioma (MPM) is an insidious primary neoplasm of the pleura that can be challenging to diagnose and is commonly considered to be only locally invasive. We present the case of a 74-year-old male who presented with clinical features of MPM but from whom pleural fluid and biopsies initially suggested benign pathology. He later developed diffuse bony metastases and re-examination of pleural biopsies using modern immunohistochemistry and molecular testing revealed a diagnosis of sarcomatoid and desmoplastic MPM with heterologous osteosarcomatous differentiation.