Disseminated mucormycosis with cerebellum involvement due to Rhizomucor pusillus in a patient with multiple myeloma and secondary myelodysplastic syndrome: A case report

Abstract

Mucormycosis is an angioinvasive fungal infection with a high mortality rate. Patients with hematological malignancies following voriconazole therapy are at high risk from mucormycosis. Here, the present study reports on a 68-year-old man diagnosed with multiple myeloma and secondary myelodysplastic syndrome, who was infected with disseminated mucormycosis with cerebellum involvement confirmed by mycological culture and histopathological examination. For patients with hematological malignancies who are receiving antifungal therapy, an opportunistic infection of mucormycosis should be considered if a 'breakthrough' infection occurs in the predilection sites (such as the sinuses, lungs, skin, brain and gastrointestinal tract). It is difficult to diagnose mucormycosis because of the limited reliable detection methods, and because mucormycosis often presents with an acute onset and progresses rapidly, particularly in immunocompromised patients. Antifungal therapy with amphotericin B or posaconazole should be started as soon as possible considering the empirical diagnosis.

Keywords: Rhizomucor pusillus; autopsy; hematological malignancies; mucormycosis; mycological culture; voriconazole.

Figure 1.

Imaging findings. (A) Pulmonary CT scans showing acute pneumonia in the right middle lung (23.10.2017). (B) Pulmonary CT scans showing acute pneumonia in the right middle lung (23.10.2017). (C) Pulmonary CT scans for mucormycosis in the right lower lung (December 25, 2017). (D) Pulmonary CT scans for mucormycosis in the right lower lung (December 25, 2017). (E) MRI of the cerebellum (December 28, 2017). (F) MRI of the cerebellum (December 28, 2017). (G) MRI of the cerebellum (December 28, 2017).

Figure 2.

Histological analysis of a brain sample showing broad-based non-septate hyphae consistent with Mucor species following silver staining. Magnification, ×400.

Figure 3.

Colonial and microscopic feature of the fungus, and ITS region sequencing. (A) Rhizomucor pusillus in blood agar. (B) ITS sequence peak maps. (C) Lactophenol cotton blue mount preparations. Magnification, ×400. ITS, internal transcribed spacer.