A Rare Case of Epithelioid Variant of Duodenal Gastrointestinal Tumour

Abstract

Gastrointestinal stromal tumours (GISTs) are uncommon mesenchymal neoplasms of the digestive tract that develop from pluripotent mesenchymal stem cells. GISTs develop from interstitial cells of Cajal or their precursors that are distributed throughout the muscular wall of the gastrointestinal tract.

Rare mesenchymal neoplasms of the gastrointestinal tract called gastrointestinal stromal tumours (GISTs) are derived from pluripotent mesenchymal stem cells. The interstitial cells of Cajal or their progenitors, which are dispersed throughout the muscular wall of the gastrointestinal system, give rise to gastrointestinal stromal tumours (GISTs). At a median age of 55–60 years old, they have an incidence of 10–20/million each year.^[1-4] They develop mostly in the stomach (60%) and small intestine (35%) before developing in the rectum, oesophagus, omentum, and mesentery  more than 5%. ^[2] Only less than 5% of GISTs are duodenal.^[5] The majority of cases are sporadic, however 5% involve a family condition, such as neurofibromatosis type 1 or the Carney triad.^[2] As a result of blockage, anaemia, or gastrointestinal bleeding from a core ulceration, they typically manifest with abdominal discomfort. The discovery of small duodenal GISTs during gastroscopy is possible.

Within the GIST category, the epithelioid variant represents a distinct subtype that is less common than other variants, such as spindle cell or mixed cell types. The overall prevalence of epithelioid GISTs is relatively low compared to other subtypes. Large extragastric components may extend intraluminally or to the serosal side in larger tumours. GISTs have non-specific abdominal pain and distention as their clinical signs and symptoms; as a result, diagnosis and treatment are frequently delayed, which result in therapeutic failures and high morbidity and fatality rates. GISTs can exhibit a variety of histological subtypes under a microscope, including the spindle cell type (70%) and the epithelioid type (20–25%), as well as the combined spindle cell and epithelioid type. ^[6] The histopathological features of epithelioid GISTs have been extensively studied in the literature. One study by Pai et al. (2016) found that epithelioid GISTs had higher cellularity, higher mitotic counts, and more prominent nucleoli than other GIST subtypes. ^[7] Cytologically, the features of duodenal GIST resemble those of adenocarcinoma. Epithelioid Duodenal GIST must be differentiated from adenocarcinoma.

We are reporting the case of a 68-year-old female who complained of pain abdomen, and constipation since 1 year. Pain was associated with nausea, vomiting, not able to digest food solid>liquid and USG guided FNAC was advised. Cytological features confirmed the diagnosis of epithelioid variant of duodenal GIST.