A Disseminated Mycobacterium Abscessus Infection in a Patient Affected by Pulmonary Graft versus Host Disease: Case Report with a Revision of Literature

Abstract

Mycobacterium abscessus complex, hereinafter Mab, is a taxonomic group of rapidly growing, nontuberculous mycobacteria (NTM). Despite major advances in understanding virulence, pathogenicity and mechanism of antibiotic resistance, Mab remains a significant cause of pulmonary and extra-pulmonary disease. Herein, we describe a disseminated, macrolide-resistant, Mab subspecies abscessus infection occurring in a severely immune-compromised 34-year-old allotransplanted female patient affected by pulmonary chronic graft versus host disease (cGVHD). The infection was characterized by hematogenous spread, and besides lungs, it involved skin, and soft tissues, resulting in a highly debilitating, painful, and finally fatal disease. Our case describes the severe impact of Mab infections in the setting of allogeneic hematopoietic stem cells transplant (alloHSCT) and related complications. It also highlights the unmet need of preventive and surveillance measures together with the urgency of developing effective vaccines and drugs against emerging NTM. The scarce literature regarding Mab infections in alloHSCT patients is also reviewed.

Keywords: Mycobacterium abscessus complex; haploidentical hematopoietic stem cell transplant; nontuberculous mycobacteria; pulmonary chronic graft versus host disease.

Figure 1

Chest HRCT showing pulmonary cavitated lesions with thick walls (arrows) and nodules in the upper lobes (A), and extensive ground-glass opacities in the lower lobes (B).

Figure 2

Overview of leg skin lesions with a detail of nodules on the right thigh (A), and photographic enlargement of abscessed lesions (B); histological analysis of skin biopsy evidencing a diffuse nodular suppurative inflammation with pseudocystic spaces involving the dermis and subcutis (Hematoxylin-eosin, original magnification ×8) (C), and abundant microorganisms (arrow) identifiable within the pseudocystic spaces by Ziehl-Neelsen staining (original magnification ×400) (D); FDG-CT/PET images showing an increased uptake at skin and soft tissues levels, with those of the right tight and sacrum presenting the maximum value (SUV 5.4) (E), and an increased uptake (arrow) in correspondence of lung lesions (F).