Granuloblastomas of the Stomach (So-Called Eosinophilic Granulomas) — A Variant of Fibrous’ Histiocytomas?

Activating PDGFRA mutations in inflammatory fibroid polyps occur in exons 12, 14 and 18 and are associated with tumour localization

“…For a long time IFP were considered as reactive and benign lesions, 3–5 until recognition of a familial occurrence suggested a genetic background 6 . Indeed, recent studies revealed that IFP harbour activating mutations in the PDGFRA gene involving exons 12 or 18.…”

Fibroid polyps of intestinal tract are inflammatory‐reactive proliferations of CD34‐positive perivascular cells

“…They arise in the submucosa or the deeper portion of the lamina propria of the mucosa and are a poorly circumscribed mass of loose mesenchymal tissue, mainly composed of spindle cells often arranged in a very characteristic onion-like pattern around blood vessels and sometimes also around mucosal glands. Formerly FP were though to be tumours and regarded as haemangiopericytomas 1 , haemangioendotheliomas 2 , fibromas 3 , fibrous histiocytomas 4,5 , or neurogenic tumours 6 . Today it is well accepted that they are reactive, and not neoplastic, which is strongly supported by the fact that their growth is self-limiting and that neither recurrences nor metastases have been observed 7,8 .…”

Inflammatory myofibrohistiocytic proliferation presenting as giant gastric pseudotumor

“…IMP is the current designation for a poorly understood entity consisting of mass-like accumulation of myofibroblasts and inflammatory cells [1]. The le- sion is most common in the lung, but can occur in the stomach, small intestine, mesentery, liver, pancreas, kidney, retroperitoneal space, lymph nodes, and even the brain and meninges [1][2][3][4][5][6]. It is uncertain whether the lesion is neoplastic or inflammatory in nature.…”

“…The term inflammatory myofibrohistiocytic proliferation (IMP) has been recently coined to encompass an array of benign soft tissue lesions previously designated as plasma cell granuloma, granuloblastoma, inflammatory pseudotumor, fibrohistiocytoma, inflammatory fibroid polyp, lymphoid hamartoma, eosinophilic granuloma, and xanthomatous pseudotumor [1,2]. This lesion is a benign proliferation of myofibroblasts and inflammatory cells, and is most often found in the lungs of young adults [1,3].…”

“…This lesion is a benign proliferation of myofibroblasts and inflammatory cells, and is most often found in the lungs of young adults [1,3]. Intraabdominal involvement by IMP can occur with lesions involving the wall of the stomach, duodenum and ileum, or the mesentery or retroperitoneum [1][2][3][4][5][6].…”