Gastrointestinal Stromal Tumors, Intramural Leiomyomas, and Leiomyosarcomas in the Duodenum: A Clinicopathologic, Immunohistochemical, and Molecular Genetic Study of 167 Cases

Abstract

In this study we analyzed the clinicopathologic features of duodenal smooth muscle or stromal tumors, including 156 GISTs, 6 leiomyomas (LMs), and 5 leiomyosarcomas (LMSs) from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki. GISTs were documented as KIT positive (n = 109); 47 tumors were also included because of their histologic identity to KIT-positive cases. GIST-specific c-kit gene mutations were documented in exon 11 in 9 of 30 cases (30%) and exon 9 in 4 of 30 cases (13%). The GISTs occurred in patients with an age range of 10-88 years (median 56 years); 54% were male. Ten patients had neurofibromatosis type I; six of them had multiple GISTs. The GISTs ranged from small asymptomatic intramural or external nodules to large masses that extended into the retroperitoneum (median size 4.5 cm). They were mostly spindle cell tumors; three malignant GISTs had an epithelioid morphology, and 81 cases had skeinoid fibers. The tumors often coexpressed CD34 and KIT (54%) and were variably positive for smooth muscle actin (39%) and S-100 protein (20%) but never for desmin. A total of 86% of patients with tumors >5 cm with >5 mitoses/50 high power fields (HPF) (n = 21) died of disease, whereas no tumor <2 cm with <5 mitoses/50 HPF (n = 12) recurred or caused death. Long latency was common between primary operation and recurrences or metastases; either one occurred in 49 of 140 patients with follow-up (35%). No formula could accurately predict metastases, which occasionally developed even if mitotic activity was <5/50 HPF and size <5 cm. Metastases were in the abdominal cavity, liver, and rarely in bones and lungs but never in lymph nodes. Four actin- and desmin-positive and KIT-negative benign intramural LMs were similar to those more often seen in the esophagus. There were five LMSs, one of which formed a polypoid intraluminal mass; all were actin positive and KIT negative. The great majority of duodenal mesenchymal tumors are GISTs, which have a spectrum from small indolent tumors to overt sarcomas. LMs and LMSs are rare.

Gastrointestinal stromal tumors: what do we know now?

“…Unfortunately, our knowledge of these additional mutations remains limited, and current recommendations for assessing prognosis are based on three simple parameters: tumor size, tumor location, and mitotic index (mitoses/5 mm 2 ). A number of risk assessment schemes have been published; the most widely used scheme was developed at the Armed Forces Institute of Pathology by Miettinen et al [117][118][119] , whose considerable efforts in studying the outcome of patients before the advent TKIs have provided the most complete data available (Table 3). It should be noted that tumor rupture, either before or during surgery, is another important negative prognostic factor.…”

Laparoscopic Resection of a Gastric Glomus Tumor

“…They are mesenchymal tumors composed of smooth muscle cells representing the neoplastic complement to perivascular glomus bodies which help regulate arteriolar blood flow. The majority of glomus tumors occur in the distal extremities, classically in the subungual areas [1]. Kay and colleagues were the first to report glomus tumors in the stomach in 1951 [2].…”

“…Kay and colleagues were the first to report glomus tumors in the stomach in 1951 [2]. They are most commonly found in the antrum and have a predilection for the greater curve [1]. Patients can present with symptoms of gastrointestinal bleeding or ulcer-like epigastric pain; however, a significant number are found incidentally on endoscopy [3].…”

“…They are almost always benign, but there is one reported cases of malignant behavior, in a tumor greater than 5 cm [1]. Their benign nature and small size make them well suited for laparoscopic resection [6].…”

Gastrointestinal tract spindle cell lesions—just like real estate, it's all about location

“…They are rare in the GI tract and arise more commonly in the skin. The largest series of GIT glomus tumors (from the Armed Forces Institute of Pathology (AFIP) 1 ) showed a female predominance and a median age at presentation of 55 years. A smaller Korean series limited to gastric glomus tumors showed a male predominance.…”