Sarcoidosis and malignant neoplasm are frequently encountered pulmonary diseases, but
their combined existence in the same patient is rare. As sarcoidosis usually presents as
mediastinal lymphadenopathy, its concurrence in lung cancer patient radiologically mimics
mediastinal metastasis and this can be possibly interpreted as unresectable disease. We
report here on a case of lung adenocarcinoma associated with sarcoidosis that developed in
a 64 year-old male who underwent surgical resection. Radiological examinations revealed
5.7 cm-sized mass in the right upper lobe with an enlargement of the bilateral supraclavicular,
highest mediastinal, subcarinal and the upper and lower paratracheal lymph nodes. Histologic
examination showed a well differentiated adenocarcinoma with non-caseating epithelioid
granulomas in the lung. The enlarged peribronchial and mediastinal lymph nodes also
revealed sarcoid granulomas without cancer metastasis. A good prognosis may be expected
for those cases of lung cancers with non-caseating granulomas in the regional lymph nodes.
The patient presently has no symptoms or signs of tumor, without further treatment since his
surgery.