Spleen findings in generalized mastocytosis. A clinicopathologic study

Abstract

Background. Little information regarding the morphologic findings of the spleen in generalized mastocytosis (GM) is available and no comprehensive review of the literature on this subject has been published. Methods. The authors reviewed their records to study the macroscopic and microscopic features of the spleen in 53 patients; the authors also studied these features in 135 patients reported in the literature. Thus, a total of 188 patients with GM were studied. Results. Splenomegaly was noted in 72% of the patients, including 71% of the patients from the authors' files and 73% of the patients reported in the literature. The spleen weight, recorded in 39 of the patients, ranged from 160 g to 2300 g; in 29 (80%) patients the spleen weighed more than 500 g and in 4 (10%) patients, more than 2000 g. However, mast cell (MC) infiltration of the spleen was recorded in only 65 (34%) patients (patients from authors' records, 39%; patients reported in literature, 32%). The following combinations were extremely rare: splenomegaly without evidence of MC infiltration (n = 1); and histologic evidence of MC infiltration in the absence of splenomegaly (n = 2). The histologic findings of the spleen could be assessed in nine of the patients from the authors' files, eight of whom had MC infiltration. In four patients, infiltration was diffuse and confined mainly to the red pulp; in the other four patients, it was more focal and involved mainly the white pulp. Spleen plasmacytosis was found in eight patients, eosinophilia in five, hemosiderosis in seven, and fibrosis in six. Concurrent acute nonlymphoblastic leukemia was diagnosed in four patients, none of whom had the skin lesions of urticaria pigmentosa. Conclusions. The authors' findings show that (1) splenomegaly is a common finding in GM and often is pronounced; (2) MC infiltration probably is the most important factor in the pathogenesis of splenomegaly in this disease; and (3) two different patterns of MC infiltration (diffuse and focal) can be identified in GM. Cancer 1992; 70:459–468.

Ultrasonographic findings in abdominal mast cell disease: a retrospective study of 19 patients

“…Splenomegaly was found in 72% of 188 human patients with systemic mast cell disease. The most important factor contributing to splenomegaly was infiltration by mast cells 29 . Splenic fibrosis, thickened capsule, and extramedullary hematopoiesis are also seen 30 .…”

KIT mutation analysis in mast cell neoplasms: recommendations of the European Competence Network on Mastocytosis

“…{Valent, 2014 #1529} In addition, other visceral organs, such as the spleen, liver, GI tract or lymph nodes, may be affected in SM. {Travis, 1988 #1470;Diebold, 1991 #1469;Metcalfe, 1991 #637;Horny, 1992 #281;Mican, 1995 #645;Horny, 1997 #272;Smith, 1999 #1468;Jensen, 2000 #527} However, we do not recommend routine screening of these organs for the presence of KIT mutations. Involvement of a single extramedullary (visceral) organ in SM in the absence of BM involvement is an extremely rare condition.…”

Systemic mastocytosis associated with acute myeloid leukaemia: report of two cases and detection of the c‐kit mutation Asp‐816 to Val

“…Indolent SM usually presents with UP‐like skin lesions and bone marrow (BM) infiltrates, but no organ impairment. However, in malignant SM, an extensive and progressive infiltration of visceral organs by neoplastic MC may lead to organ impairment or even organ failure ( Lennert & Parwaresch, 1979; Horny et al , 1985 , 1992a, b; Horny & Kaiserling, 1988 ; Travis et al , 1988a ). Mast cell leukaemia is a rare disease characterized by the presence of circulating MC and a very unfavourable prognosis ( Coser et al , 1980 ; Dalton et al , 1986 ; Travis et al , 1986 ).…”