A Rare Giant Gastrointestinal Stromal Tumor in an Elderly Patient

Abstract

Although gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract, they are the most common mesenchymal tumors of the gastrointestinal tract. The majority of these tumors occur in the stomach, but they could be found anywhere along the gastrointestinal tract. A 72-year-old man presented with a large intra-abdominal mass. A Tru cut biopsy revealed features of a GIST. He underwent a resection of the intra-abdominal mass along with a partial gastrectomy and splenectomy. His postoperative course was uneventful.

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are benign tumors of the gastrointestinal tract accounting for 0.1%–3% of all gastrointestinal tumors.[1] They were initially misclassified as leiomyomas, but further research has shown that they originate from the interstitial cells of Cajal, an intestinal pacemaker.[2,3,4] Most of these tumors arise as a result of mutations in KIT, a regulator of tyrosine kinase.[2,4]

Our patient presented with 1 year of progressively increasing intra-abdominal mass. This article discusses the patient’s presentation, comorbidities, treatment, and postoperative course to highlight the possibility of performing a resection on an elderly patient.

CASE REPORT

We present a 72-year-old man with a 1-year history of progressively increasing intra-abdominal mass. There was no associated abdominal pain, vomiting, hematemesis, or rectal bleeding. He, however, had a history of early satiety and weight loss.

The patient is a known hypertensive on amlodipine and a known diabetic on metformin.

A general physical examination revealed an elderly man, afebrile, pale, anicteric, not cyanosed, in no obvious distress, and with bilateral pitting edema up to the knees. Abdominal examination revealed a large firm mass measuring 22 cm × 20 cm × 16 cm extending from the left hypochondria to the right iliac fossa.

A preoperative computed tomography (CT) scan revealed a 22.5 cm × 19.4 cm × 16 cm mass abutting and dislocating the stomach to the right side of the abdomen. A Tru cut biopsy revealed features suggestive of a GIST.

He was scheduled for an exploratory laparotomy and had a retroperitoneal tumor resection + partial gastrectomy + splenectomy through a chevron incision. Intraoperative findings revealed a large retroperitoneal tumor attached to the spleen and the stomach. The feeding vessels were identified and ligated with the tumor resected along with a partial gastrectomy and splenectomy.

Macroscopically, the tumor was irregularly shaped, multilobulated, and partially encapsulated, weighing about 4.595 kg and measuring 30 cm × 19 cm × 12 cm. The cut surface showed variegated solid and partially cystic surfaces.

The histology of tumor samples showed spindle-shaped cells disposed in sheets, whorls, and fascicles. The nuclei were hyperchromatic and pleomorphic. There was 7/10 hpf mitosis.

His postoperative course was uneventful and he was discharged on the 10^th day postoperation. He has been recovering well since his discharge 5 months ago.

DISCUSSION

Gastrointestinal tumors are uncommon tumors of the gastrointestinal tract.[1] The exact incidence in Nigeria is not well documented, but various studies estimate the incidence to be between 0.1% and 3% of all gastrointestinal tumors.[1] Most of these tumors affect the stomach followed by the small intestine and other parts of the gastrointestinal tract.[1] Cancerous variants make up about 20%–30% of all GISTs.[3,5]

Mutations in KIT genes are implicated thus tyrosine kinase inhibitors (e.g. imatinib and sunitinib) are useful for targeting these tumors.[2,3,5]

Most cases occur in individuals over 50 years of age and present with symptoms such as dysphagia, jaundice, intestinal obstruction, constipation, and gastrointestinal bleeding.[5,6]

A significant prognostic factor is the presence/absence of liver metastasis.[3]

Contrast-enhanced CT scan is the preferred imaging modality for GISTs.[1,3] These tumors frequently appear as a contrast-enhanced mass with smooth margins.[1] In patients at high risk from contrast or radiation exposure, an MRI is also a viable imaging modality.[1,3]

Definitive diagnosis is made based on histological features and immunohistochemical staining for KIT (CD 117), CD34, and DOG-1.[1,2,3,6,7]

The current gold standard for the treatment of GIST is surgery (i.e. en bloc resection) with continuous monitoring and neoadjuvant therapy with immunotherapy (e.g. imatinib) to monitor for and reduce the risk of recurrence.[2,4,8]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.