Synchronous primary gastric diffuse large B-cell lymphoma and multiple lung primary adenocarcinoma with pulmonary cryptococosis: a case report and literature review.

Background: The coexistence of non-Hodgkin's lymphoma of the stomach and multiple primary lung adenocarcinomas with pulmonary cryptococcosis has rarely been reported.

Case presentation: We herein present a 75-year-old man who was admitted to our hospital due to hematemesis. Gastroscopy and imaging revealed extensive stomach wall thickening and multiple lung lesions, including nodules and cavernous lesion. The patient was diagnosed with primary diffuse large B-cell lymphoma via gastroscopy and bilateral lung primary adenocarcinoma with cryptococcal infection via percutaneous CT-guided puncture biopsy. He subsequently underwent six cycles of R-CHOP regimen for gastric lymphoma, along with CT-guided radiofrequency ablation for the upper lobe of the right lung primary adenocarcinoma and radioactive particle implantation was performed on the lower lobe of the left lung primary adenocarcinoma, supplemented with antifungal therapy. After a definite diagnosis and systemic treatment, the patient was followed up for twenty-seven months with no tumor recurrence, progression or metastasis.

Conclusion: To the best of our knowledge, the complex combination of multiple primary malignancies and pulmonary cryptococcal infection is extremely rare. The diagnosis is been confusing and challenging. CT-guided needle biopsy can help achieve pathological diagnosis, elucidate the type and stage of the tumor, and even change the clinical treatment strategy, which is necessary and beneficial.