Inflammatory pseudotumour associated with chronic persistent Eikenella corrodens infection: a case report and brief review

Abstract

Inflammatory pseudotumour is an uncommon mass forming lesion, representing the histological expression of an infective or reactive/reparative process (pseudotumour) in most cases, and a bona fide neoplasm (for example, inflammatory myofibroblastic tumour) in a minority of cases. This report describes the case of an inflammatory pseudotumour with a pathology that unveiled proliferative CD68 positive and actin negative spindle shaped cells, with a mild mixed inflammatory infiltrate, and a culture that yielded an uncommon fastidious bacillus, Eikenella corrodens. The clinical course was indolent but protracted, with insidious progression to multifocal non-contiguous lesions, involving the lungs, liver, spleen, left kidney, and deep neck tissue, all of which responded to medical treatment with appropriate antibiotics. It is of paramount importance that clinicians search for an infective cause of an inflammatory pseudotumour, to ensure appropriate treatment.

Figure 1

The upper panel shows a computerised tomography (CT) scan revealing a heterogeneously enhancing hepatic mass in the right lobe, and a smaller lesion with irregular rim enhancement in the spleen. The lower panel shows a follow up CT scan three months later, which reveals nearly total resolution of the lesions.

Figure 2

Proliferation of spindle shaped cells in a vaguely fascicular pattern with focal entrapment of a bile ductule in the hepatic inflammatory pseudotumour (haematoxylin and eosin stained; original magnification, ×200).