Abstract: Cutaneous cryptococcosis, an infectious disease resulting from Cryptococcus neoformans , primarily affects immunodeficient individuals. Here, we report a case of mediastinal small cell carcinoma (MSCC) complicated with multiple skin and soft tissue infections mimicking erysipelas and cellulitis. Antibiotics for bacteria were ineffective and a culture of pus from the infected areas revealed Cryptococcus neoformans  in this patient. The absence of any evidence indicative of systemic cryptococcal infection leads to a final diagnosis of primary cutaneous cryptococcosis (PCC). Following two weeks of fluconazole at 400 mg/day and 200 mg/day for the subsequent three months, combined with incision, irrigation and drainage, the wound gradually healed. An analysis and discussion of the clinical features of this patient are presented. This case alerts clinicians as to the possibility of Cryptococcus neoformans  in patients with advanced malignant tumors complicated with multiple skin and soft tissue infections. While a timely diagnosis and treatment of PCC in this patient resulted in a favorable outcome, the patient succumbed to the malignant tumor at six months post-discharge.
Keywords: mediastinal small cell carcinoma, primary cutaneous cryptococcosis, Cryptococcus neoformans , immunodeficiency, therapy