Gastrointestinal Stromal Tumors Mimicking Gynecologic Disease: Clinicopathological Analysis of 20 Cases

Abstract

Diagnosis of pelvic gastrointestinal stromal tumors (GISTs) can be challenging because of their nonspecific presentation and similarity to gynecological neoplasms. In this series, we describe the clinicopathological features of 20 GIST cases: 18 patients presented with pelvic mass and/or abdominal pain concerning gynecological disease; 2 patients presented with a posterior rectovaginal mass or an anorectal mass. Total abdominal hysterectomy and/or salpingo-oophorectomy (unilateral or bilateral) were performed in 13 cases. Gross and histological examination revealed that the ovary/ovaries were involved in three cases, the uterus in two cases, the vagina in two cases and the broad ligament in one case. Immunohistochemically, all tumors (20/20, 100%) were diffusely immunoreactive for c-KIT. The tumor cells were also diffusely positive for DOG-1 (10/10, 100%) and displayed focal to diffuse positivity for CD34 (11/12, 92%). Desmin was focally and weakly expressed in 1 of the 14 tested tumors (1/14, 7%), whereas 2 of 8 tumors (2/8, 25%) showed focal SMA positivity. At the molecular level, 7 of 8 (87.5%) GISTs with molecular analysis contained c-KIT mutations with the second and third c-KIT mutations detected in some recurrent tumors. In addition to c-KIT mutation, a pathogenic RB1 mutation was detected in two cases. We extensively discussed these cases focusing on their differential diagnosis described by the submitting pathologists during consultation. Our study emphasizes the importance of precision diagnosis of GISTs. Alertness to this entity in unusual locations, in combination with clinical history, morphological features as well as immunophenotype, is crucial in leading to a definitive classification.

Gross architecture of ovarian specimens from a southwest Nigerian tertiary healthcare facility

“…13 There have been rare reports of GIST metastasizing to the ovary. [14][15][16][17] From our study, we found a case of metastasis of GIST to the left ovary. This was in a 54-year-old woman.…”

Primary Extra Gastrointestinal Stromal Tumors of Vagina: A Rare Case Report without Gastroenterology Manifestations

“…Another study showed that 56.2% (9/16) of incidentally found GISTs in gynecological surgery were located in the stomach wall, cecum, omentum and mesentery [9]. These cases also presented with GI symptoms, such as abdominal pain [7]. This case is unique as the patient only complained vaginal bleeding without any GI symptoms.…”

“…The majority of the EGISTs cases in the pelvic involved the GI tracts, as shown in a 10-year retrospect pelvic GISTs study where 65% (13/20) cases originated from small bowel, 15% (3/20) originated from rectum, 15% (3/20) originated from stomach and 1 had unavailable primary site information [7]. Another study showed that 56.2% (9/16) of incidentally found GISTs in gynecological surgery were located in the stomach wall, cecum, omentum and mesentery [9].…”

“…CD117 (C-kit) and GOG-1 have the most diagnostic value in GISTs, and CD117 is not expressed in all non-GIST tumors. One study showed that 100% (20/20) tumor were immunoreactive for c-kit and 100% (10/10) for DOG-1 [7], and another large cohort of population showed that 96.5% (798/27) cases of GISTs exhibited KIT gene mutations [8]. However, a small percentage (5-7%) of GISTs may show negative expression of CD117.…”

Uterine MEIS1::NCOA2 Fusion Sarcoma With Lung Metastasis: A Case Report and Review of the Literature

“…For this reason, high-grade endometrial stromal sarcoma entered the differential diagnosis despite focal/nondiffuse positivity of cyclin D1 and negative BCOR staining. Although CD117 was diffusely positive, a gastrointestinal stromal tumor was not included in the differential diagnosis because of a negative DOG-1 immunostaining and location 16 . The mechanism which drives CD117 expression is unclear since c-KIT mutation or amplification was not detected in this tumor.…”