A Case of KIT-Negative Extra-Gastrointestinal Stromal Tumor of the Lesser Omentum

Abstract

We report the unique case of a 69-year-old man with an extra-gastrointestinal stromal tumor (EGIST) in the lesser omentum. Based on the location of the tumor and the radiological findings, we made a provisional diagnosis of hepatic cavernous hemangioma in the lateral segment. However, after 5 years of follow-up, tumor growth was noted and the patient underwent a laparotomy. The tumor was located in the lesser omentum and resected en bloc with its fused lesser omentum and an adherent portion of the liver. The pathology results indicated an EGIST with microscopic proliferation of epithelioid cells in the lesser omentum; the tumor was immunohistochemically negative for KIT staining and positive for CD34 and PKC theta. Because of the rarity of mitotic figures and the low Ki-67 labeling, the tumor was diagnosed as a KIT-negative EGIST with a low malignant potential. The patient was followed up without receiving imatinib mesylate treatment and has remained free of any signs of recurrence for 26 months. The present case report describes a very rare lesser omental KIT-negative EGIST.

Clinicopathological features and prognosis of omental gastrointestinal stromal tumor: evaluation of a pooled case series

“…Literature search of MEDLINE was performed for all articles in English published from 1998 through 2015. MEDLINE search resulted in 47 case reports 8 9 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 including 57 patients and 6 case series 61 62 63 64 65 66 including 40 cases. As a result, a total of 99 omental GISTs patients were identified.…”

Extragastrointestinal stromal tumor of lesser omentum: a challenging radiological and histological diagnosis

“…Recently, Ogawa et al [8] have reported a case of EGIST of the lesser omentum, which was initially classified as a benign liver tumor (hemangioma or INF); at histological examination it was, curiously as in our case, an epithelioid subtype, with CD117 negative. These facts could suggest a possible correlation between uncommon pathological features and atypical radiological appearances that, in our opinion, should be investigated.…”

Gastrointestinal stromal tumor of the lesser omentum: a case report and review of the literature

“…[5]22MGIST of the stomach27SpindleUnknownOgawa et al . [6]69MHepatic hemangioma80EpithelioidNoneSkandalos et al . [10]79FTumor of the pancreas110SpindleNoneTrombatore et al .…”