A Rare Case of Spontaneous Closure of Tracheomediastinal Fistula Formed after Chemotherapy for Diffuse Large B-Cell Lymphoma.

Tracheomediastinal fistula is a rare but potentially life-threatening complication associated with malignant lymphoma. We report a case of spontaneous closure of a tracheomediastinal fistula that developed after chemotherapy for mediastinal diffuse large B-cell lymphoma (DLBCL). A 70-year-old man presented with airway compression caused by a large mediastinal tumor. After airway stabilization with a Dumon Y stent and subsequent R-CHOP chemotherapy, the tumor markedly regressed. Following stent removal, a fistula developed in the anterior tracheal wall, communicating with a necrotic mediastinal space. Because no clinical or laboratory signs of mediastinitis were observed, conservative management without antibiotics or invasive intervention was adopted. The fistula gradually decreased in size and closed completely within 10 weeks. This case suggests that tracheomediastinal fistulas without mediastinitis may be managed conservatively under careful observation. Treatment strategies should be individualized based on anatomical location and the presence or absence of infection.