Thank you, Dr Scharman, for an exhilarating case of a 69 year old male who presented with a petechial rash covering his bilateral lower extremities in the setting of a recent incidentaloma of a mediastinal mass and new pancytopenia found to have a thymoma.

What a case-- jam-packed with items ripe for differential making! Petechial rash! Pancytopenia! Mediastinal Mass! Since the first two findings are encountered rather frequently, let’s talk about mediastinal masses.

I whipped up a quick visual aid (see below) but you can also just remember “the cartoon network” or “that crazy Neukam” or “totally cool Nikes” or any mnemonic for the letters “TCN” to help you remember the differential for anterior, middle and posterior mediastinal masses.


As we learned from Dr Scharman, the paraneoplastic syndromes associated with thymic neoplasm are many and can present in myriad ways. This table from Up to Date outlines this nicely. (annotations made to highlight what our patient had).

So the lesson from today is, if you see a mediastinal mass and well… any other symptom!... think thymoma and it’s attendant paraneoplastic syndromes.