Unique case report of a chromomycosis and Listeria in soft tissue and cerebellar abscesses after kidney transplantation

Abstract

Background: Chromomycosis is a rare mycotic infection encountered in tropical and subtropical regions. The disease presents as a slowly-evolving nodule that can become infected with bacteria. Here, we describe a unique association of abscesses caused by a chromomycosis and Listeria monocytogenes in a kidney transplant recipient, and didactically expose how the appropriate diagnosis was reached.

Case presentation: A 49-year old male originating from the Caribbean presented a scalp lesion which was surgically removed in his hometown where it was misdiagnosed as a sporotrichosis on histology, 3 years after he received a kidney transplant. He received no additional treatment and the scalp lesion healed. One year later, an abscess of each thigh due to both F. pedrosoi and L. monocytogenes was diagnosed in our institution. A contemporary asymptomatic cerebellar abscess was also found by systematic MRI. An association of amoxicillin and posaconazole allowed a complete cure of the patient without recurring to surgery. Histological slides from the scalp lesion were re-examined in our institution and we retrospectively concluded to a first localisation of the chromomycosis. We discuss the possible pathophysiology of this very unusual association.

Conclusion: In this case of disseminated listeriosis and chromomycosis, complete cure of the patients could be reached with oral anti-infectious treatment only.

Keywords: Antifungal therapy; Case report; Fonsecaea; Kidney transplantation; Listeria; Tropical pathology.

Fig. 1

CT scan views of the thigh abscesses. The infection presents as an isodense image located within the muscles with a small necrotic centre. a: coronal view of the left thigh abscess. b: axial view of the left and right abscesses. The presence of air in the right thigh abscess is due to a wick that was left to ensure drainage of the abscess

Fig. 2

Direct examination of the pus drawn from the right thigh abscess. The microscopic examination showed fungal element called fumagoid cells (also called muriform cells or sclerotic bodies), which are indicative of chromoblastomycosis. Fumagoid cells are rounded brown pigmented septated structures with internal inclusions (optical microscopy, 40 X magnification)

Fig. 3

Microscopic examination of the fungal culture collected from the right thigh lesion. Conidiophore indicative of Fonsecae sp. are visible (optical microscopy, 40 X magnification)

Fig. 4

MRI of the central nervous system at diagnosis. Gadolinium enhanced T1 axial (a), and coronal (b) views. The images show an isolated left posterior cerebellar lesion consistent with an abscess

Fig. 5

MRI of the central nervous system 3 months after amoxicillin treatment and posaconazole initiation. The imaging shows total regression of the cerebellar lesion