Cladosporium cladosporioides Fungemia in a Patient with Non-Hodgkin Lymphoma: An Extremely Rare Case and Review of the Literature

<b>Background and Clinical Significance</b>: <i>Cladosporium cladosporioides</i> is a ubiquitous dematiaceous mold that is rarely implicated in invasive human diseases and often considered a saprophyte and plant pathogen. <b>Case Presentation</b>: We report an extremely rare case of <i>C. cladosporioides</i> fungemia in a 61-year-old man with mantle cell lymphoma undergoing chemotherapy. The patient developed fever, dry cough and cavitary pulmonary lesions in the setting of profound immunosuppression. Blood cultures yielded slow-growing dark pigmented mold after prolonged incubation and species identification was achieved using MALDI-TOF mass spectrometry with an alternative fungal database, supported by microscopic morphology. Serum 1,3-β-D-glucan levels were markedly elevated, while galactomannan antigen testing was negative. Antifungal susceptibility testing demonstrated activity of triazoles and targeted therapy with voriconazole led to clinical improvement. A review of the literature identified only five previously reported cases of invasive <i>C. cladosporioides</i> infections worldwide, involving primarily pulmonary and central nervous system disease. <b>Conclusions</b>: To the best of our knowledge, this is the first documented case of fungemia caused by this species. The current report highlights the pathogenic potential of <i>C. cladosporioides</i> in immunocompromised hosts, the diagnostic challenges posed by slow-growing dematiaceous fungi, the importance of prolonged culture incubation, fungal biomarkers and advanced identification techniques for timely diagnosis and management.