Inflammatory Pseudotumor of the Spleen:Report of a Case with an Immunohistochemical Study

Abstract

A 81‐year‐ old Japanese man with a splenic inflammatory pseudotumor is described. The pseudotumor was un changed in size after one year of observation. Macro‐scopically, the lesion was a firm well‐circumscribed 5.5X 5×5cm mass showing a yellowish‐white cut surface. Histologically, it was composed of abundant mixed inflammatory infiltrates, predominantly UCHL‐1(+) T and L26(+) B lymphocytes, plasma cells containing various immunoglobulin subtypes, and S 100 protein(+), and lysozyme and NCA(+) histiocytes, with a sclerotic stroma. Small numbers of eosinophils, neutrophils and foamy macrophages were admixed. The patient has remained disease‐free for 14 months after splenectomy. Only ten splenic inflammatory pseudotumors have been reported in the literature. This paper adds an additional case, together with details of immunohistochemical polyclonality of each inflammatory cell population, confirming that this disease is a nonspecific inflammatory change. Acta Pathol Jpn 42:376–381, 1992.

Inflammatory myofibroblastic tumour of the spleen: A case report and literature review

“…PSL as a lymphoma usually involves the spleen and splenic hilar lymph nodes 20,21 . Similar to IMT, PSL tends to be asymptomatic and present as a large mass within the spleen on radiology 22,23 . From a review of the literature, it seems that the initial diagnosis of PSL and IMT are made only occasionally at splenectomy 24 …”

“…20,21 Similar to IMT, PSL tends to be asymptomatic and present as a large mass within the spleen on radiology. 22,23 From a review of the literature, it seems that the initial diagnosis of PSL and IMT are made only occasionally at splenectomy. 24 Microscopically, three basic histological patterns are recognized: (i) myxoid, vascular and inflammatory areas resembling nodular fasciitis; (ii) compact spindle cells with intermingled inflammatory cells (lymphocytes, plasma cells, eosinophils) resembling fibrous histiocytoma; and (iii) dense plate-like collagen resembling a desmoid or scar.…”