Inflammatory pseudotumor of spleen. Report of two cases and literature review.

OBJECTIVE: We report two new cases of inflammatory pseudotumor of the spleen and review the cases reported to date. We discuss the diagnostic value of the clinical manifestations, the modern image technics and the laboratory data and conclude that only pathological and immunohistochemical studies allow a reliable diagnosis of this disease. DATA SOURCES: We have obtained the cases for the review through a computer search with the system SilverPlatter 3.11 (SilverPlatter Software Copyright NU 1992). The new cases have been obtained from our files. DATA SYNTHESIS: 53% were random findings (47% in the workup of another disease and 5% at autopsy). In the remaining cases, the clinical signs were not specific and none of the image technics could establish diagnosis. Neither fine needle aspiration nor laboratory data rendered conclusive results. Only pathological and immunohistochemical study after splenectomy allowed diagnosis. The clinical signs disappeared in all the cases following splenectomy and none of the patients have had recurrences. CONCLUSIONS: Inflammatory pseudotumor is a benign disease of unknown etiology and pathogenesis. It consists of solitary or multiple tumors that can affect virtually any organ. Clinical signs are non-specific. This lesion can render diagnostic problems with neoplasms of the lymphoreticular system. Splenectomy is diagnostic and curative.

Gastrointestinal autonomic nerve tumours and their separation from other gastrointestinal stromal tumours: an ultrastructural and immunohistochemical study of seven cases.

Gastrointestinal stromal tumours (GIST) represent a heterogeneous group whose classification frequently requires ultrastructural and immunohistochemical studies. In a retrospective study of the ultrastructural findings of 24 gastrointestinal stromal tumours, whose light microscopic study has yielded ambiguous results and in which accurate diagnosis had required ultrastructural support, seven were found to have the characteristics of gastrointestinal autonomic nerve (GAN) tumours. In all of them the diagnosis was based on the presence of dendritic processes with dense neuroendocrine granules. Immunohistochemically, the seven tumours were negative for smooth-muscle markers. All stained positively for vimentin. NSE, chromogranin, and synaptophysin were positive in most of them, while S-100 protein was positive only in two cases. We present the ultrastructural and immunohistochemical features of seven GANT against the background of the GISTs of our series. We conclude that GAN tumours cannot be diagnosed by light microscopy alone but this tumour group displays characteristic electron microscopic and immunohistochemical features and appears to represent a distinct type of GIST.