[Spontaneous remissive pulmonary sarcoidosis in a patient with a history of surgical resection of lung adenocarcinoma: a case report].

Pulmonary patches with mediastinal lymphadenopathy could be showed in both lung cancer and sarcoidosis. There are certain similarities in their imaging manifestations, and histopathological examination is necessary for diagnosis. This article reports a case of a 62-year-old female patient who had a history of early-stage lung adenocarcinoma and underwent surgical treatment. She had been followed up regularly without signs of recurrence. More than three years after the surgery, she presented with a new solid pulmonary mass and mediastinal lymphadenopathy, without significant clinical symptoms. Lung cancer recurrence was clinically suspected. However, mediastinal lymph node biopsy guided by endobronchial ultrasound revealed nonnecrotizing epithelioid-cell granulomas. Given the patient's history of diabetes, the lack of significant respiratory manifestations, and no evidence of extrathoracic involvement of sarcoidosis, we decided to closely monitor the disease course after communicating with the patient. Follow-up CT scans after two months and four months showed spontaneous remission of the pulmonary lesion and mediastinal lymphadenopathy, which was diagnosed as spontaneous remission of sarcoidosis after the history of lung cancer.