Abstract

Background: Small cell lung cancer is a neuroendocrine neoplasm representing about 15 percent of all lung cancers. Sarcoidosis is a multisystem granulomatous disease. The involvement of mediastinal lymph nodes is common in both and makes the diagnosis challenging when these conditions coexist. We report a rare case of a patient with history of sarcoidosis who was diagnosed with small cell lung cancer.

Case presentation: 65-year-old African American female with history of sarcoidosis, who presented with right sided shoulder pain for two months. CT thorax showed right upper lobe nodule with mediastinal and bilateral hilar lymphadenopathy. FDG-PET scan showed increased uptake in the right upper lobe and in mediastinal and hilar lymph nodes. She subsequently underwent an EBUS with biopsies of multiple lymph node stations. Pathology of these lymph nodes revealed non-necrotizing granulomas without evidence of malignancy. She underwent a CT guided biopsy of the right upper lobe lesion and pathology was consistent with small cell carcinoma. It was unclear whether the enlarged and active mediastinal and hilar lymph nodes were related to sarcoidosis or small cell cancer. A multidisciplinary meeting was conducted and decided to treat the patient presumably as small cell cancer with nodal disease. She was given 2 cycles of carboplatin and etoposide. Follow-up CT thorax after the second cycle showed decrease in size of the nodule along with mediastinal and hilar lymph nodes. She also underwent radiation therapy including mediastinum in the field of radiation.

Discussion: Sarcoid-like reactions have been noted either in the vicinity of the tumor or within the regional lymph nodes draining that particular tumor. This has been described in less than 1 percent of lung cancers and mostly in squamous cell lung cancers. True sarcoidosis may be confused with a sarcoid-like reaction in cancer patients. It was not possible to definitively differentiate if the nodal involvement was from sarcoidosis or small cell cancer metastasis or a sarcoid like reaction in our patient. Given the diagnostic dilemma, we treated her nodal involvement as small cell lung cancer metastasis since under treatment could lead to relapse and compromise survival.

Keywords: Granuloma, lymph nodes, mediastinum, sarcoidosis, small cell lung carcinoma