A Huge Pelvic-Abdominal Malignant GIST Tumour in a Patient with Neurofibromatosis Type 1: Case Report and Literature Review

Abstract

Gastrointestinal stromal tumours are rare tumours of the gastrointestinal tract (GIT) accounting for 0.1%–3% of all gastrointestinal tumours. The most common location is the stomach (55%) followed by the small bowel (31.8%), colon (6%), other various locations (5.5%), and the oesophagus (0.7%). They may also occur in extraintestinal locations. The signs and symptoms of GIST depend on the tumour’s location and size. Gastrointestinal bleeding is one of the most common symptoms. Other signs and symptoms include abdominal discomfort, pain or distention; intestinal obstruction, and weight loss. The association between the development of GISTs and neurofibromatosis 1 (NF1) has been established. NF1-associated GISTs tend to have a distinct phenotype, and the absence of KIT/PDGRFα mutations in turn has implications on further management when they do not respond well to imatinib treatment. Here, we present one of the largest GISTs reported in the literature with a total volume of 25.3×20×14 cm+27.9×23×8 cm and an overall weight of 7.3 kg, which developed in a 43-year-old female patient with NF1 and was resected on an emergency basis due to the rapid deterioration and development of abdominal compartment syndrome. Pathology assessment showed a malignant GIST composed of spindle cells with elongated nuclei with necrosis, marked pleomorphism and numerous giant cell. The mitotic count was >15/50 HPF, Ki 67 was 80%, and the lymphovascular invasion was clear. Immunohistochemistry investigations showed that Vimentin, CD117, and DOG1 were positive, while BCL-2 and CD99 were focal positives. Pan-CK, S-100, CD34, Desmin, SMA, and HMB-45 were negatives.

Neurofibromatosis type 1-associated gastrointestinal stromal tumor: A case report and review of the literature

“…Although the common indolent behavior of NF1-GIST, there are potentially aggressive forms, more frequent in larger tumors (>10 cm) with high cellularity and mitotic rate >10/50 HPF and coagulative necrosis. In these cases metastasis occurs mostly in the liver and peritoneum, and less frequently to the bone and lung [9].…”

A diagnostic challenge; pelvic solitary fibrous tumor (SFT) mimicking Peri‐Anal gastrointestinal stromal tumor (GIST): A case report

“…8,9 Mesentery and omentum could be also noted as the unusual areas for GIST development. 10 Most GISTs have spindle-cell type configuration that SFTs should be considered as a notable differential diagnosis for spindle-cell type GISTs. 11 Although radiologic assessments (like computed tomography (CT) scans) are beneficial tools for detecting both GISTs and SFTs, they have some diagnostic limitations because GISTs and SFTs overlap in some of their characteristics like anatomic location.…”

“…The Anorectum region is responsible for 5% of GIST cases in which the anal canal contains about 2%–8% of them 8,9 . Mesentery and omentum could be also noted as the unusual areas for GIST development 10 …”

Do you get the GIST? Successful resection of a giant 3.5 kg gastrointestinal stromal tumour

“…Interestingly, a recent meta‐analysis demonstrated similar short and long‐term surgical and oncological outcomes for laparoscopic and open approaches to large gastric GISTs greater than 5 cm, thus suggesting the former approach should be used when able for larger tumours. 5 However, there exists a relative paucity of evidence around the best management of giant GISTs and most of the literature pertaining to such large tumours consists of case reports describing en‐bloc resection, as undertaken here 6 , 7 , 8 , 9 , 10 (see Table 1 ). The present case contributes to this small body of literature and along with Table 1 demonstrates that these massive tumours can indeed be removed, en‐bloc , with a high degree of safety.…”