Diagnosis of leukemic lung infiltration mimicking fungal infection by transbronchial lung cryobiopsy: the first case report.

Background: We here report the first case of leukemic lung infiltration diagnosed by transbronchial lung cryobiopsy (TBLC). TBLC is likely to be a superior method to transbronchial forceps biopsy because TBLC can get larger specimens, resulting in a higher chance of containing the leukemic cells infiltrated tissues. TBLC is generally considered a superior diagnostic method compared to transbronchial lung forceps biopsy (TBLB) because it utilizes cryotechnology to obtain larger specimens, increasing the likelihood of capturing tissues infiltrated with leukemic cells.

Case presentation: A 69-year-old male patient with acute myeloid leukemia presented with a fever. His initial chest CT scans revealed consolidative lesions, raising suspicion of fungal infection such as angioinvasive aspergillosis or mucormycosis. TBLC and TBLB were conducted to achieve a precise diagnosis, and eventually, leukemic lung infiltration was identified exclusively in the tissues obtained from TBLC. Two cycles of chemotherapy was administrated to patient, showing improvements in symptoms and chest CT findings.

Conclusions: TBLC has greater potential as a differential diagnostic method for pulmonary lesions than TBLB in leukemia patients facing therapeutic challenges due to its higher diagnostic yield.