Seminoma and sarcoid: A confusing collision.

Abstract

339 Background: In patients with active or prior malignancy, the presence of mediastinal lymphadenopathy is often assumed to indicate metastases. However, sarcoidosis can imitate malignancy on CT and PET imaging. The incidence of sarcoidosis or “sarcoid-like reaction” in cancer patients (especially testicular germ cell tumor patients) appears to be higher than in the general population. Methods: We report a series of 4 testicular cancer patients with mediastinal adenopathy mimicking metastatic disease. Subsequent investigations and follow-up revealed sarcoid-like reaction without active malignancy. Results: A 25 year old man presented with a neck swelling and was found to have left cervical adenopathy, mediastinal adenopathy and a right testicular mass. Biopsy of the cervical nodes revealed a mixed seminoma and non-seminomatous germ cell tumour. After 4 cycles of chemotherapy PET/CT revealed persistent hypermetabolic mediastinal adenopathy. Transbronchial needle aspirate (TBNA) revealed non-caseating granulomas (NCGs). After right orchiectomy and retroperitoneal lymph node dissection he remains in complete remission. A 26 year old man presented with scrotal swelling and investigations revealed bilateral testicular seminoma. CT revealed mediastinal adenopathy. TBNA revealed NCGs and he remains disease free after orchiectomy. A 42 year old man presented with right sided scrotal swelling. CT revealed mediastinal adenopathy. TBNA revealed NCGs. He was treated successfully with orchiectomy and chemotherapy for stage 1 seminoma. A 20 yr old man had mediastinal adenopathy on a surveillance CT 5 years after high dose chemotherapy and stem cell transplant for platinum-refractory seminoma. TBNA revealed NCGs and the adenopathy resolved with oral prednisone therapy. Conclusions: Sarcoid-like reaction in cancer patients may be due to an immunologic hypersensitivity to tumor-associated antigens. Although the precise pathogenesis is unknown, the clinical relevance of this phenomenon is clear. There is a need for histologic confirmation of suspected metastatic mediastinal adenopathy in patients with testicular cancer. We are collecting more cases in other malignancies and will present an update.