Correct!
2. Melanoma
Calcified pulmonary nodules have a wide differential. There are benign causes such as granulomas, occupational exposure such as silicosis, and treated infections such as varicella. There are also malignant causes, including any osteoid matrix- or chondroid matrix- producing tumor, such as osteosarcoma and chrondrosarcoma, respectively. Also, mucin producing tumors of the gastrointestinal tract or breast can lead to mucoid calcification. Treated metastatic disease can also calcify in the case of choriocarcinoma and thyroid malignancies. Melanoma is a hypervascular tumor, but typically does not calcify. Note there is also a large middle mediastinal mass, which represents massive lymphadenopathy.
Review of the entire thoracic CT showed that only one nodule contained a focus of calcification; the remainder of the numerous, bilateral nodules were non-calcified. The patient subsequently developed abdominal pain and contrast-enhanced CT (CECT) of the abdomen (Figure 4) was performed for further evaluation.
Figure 4. Enhanced abdominal CT displayed in soft tissue windows.
There is massive retroperitoneal lymphadenopathy.
Taking into account patient’s clinical presentation and the findings in the chest, what is the most likely diagnosis? (Click on the correct answer to proceed to the fifth and final panel)