Evaluation of Pleural-Based Nodules in a 52-Year-Old Woman with a History of Metastatic Breast Cancer

A 52-y-old woman with a history of invasive ductal carcinoma had undergone right mastectomy, right axillary lymph node dissection, and breast reconstruction. Two of six axillary lymph nodes were positive for ductal carcinoma at surgery, and the patient was staged pT2 pN1a Mx. A one-month follow-up chest CT scan showed multiple left-sided pleural-based nodules suggestive of metastatic disease. PET/CT, which was performed to further characterize these nodules, did not demonstrate significant 18F-FDG uptake within them or evidence of metastatic disease (Fig. 1). In the process of formulating a differential diagnosis for these nodules, it was discovered that, as a child, the patient had sustained an accidental gunshot wound. The possibility of thoracic splenosis was suggested, and a 99mTc-labeled heat-denatured red blood cell (DRBC) scan was ordered to confirm the origin of these conspicuous pleural-based nodules.