Gastrointestinal stromal tumor of the rectum with scapular metastasis: a case report

A rectal gastrointestinal stromal tumor case accompanied by elevated CEA mimicking rectal carcinoma on 18F-FDG PET/CT

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm arising from gastrointestinal tract and can be benign or malignant. Rectal GISTs are rare and have poor prognosis. We here reported an older male who presented with features of distending discomfort in the rectum and pain in the anus due to a large rectal tumor. Physical examinations detected a mass in the rectum without blood staining on the gloved finger. Carcinoembryonic antigen (CEA) was found to be slightly elevated and the prostate-specific antigen level was normal. ¹⁸F-FDG PET/CT showed a soft tissue density mass at the bottom of the pelvic, with an unclear boundary to the surroundings with the significantly increased FDG uptake (SUVmax 17.5). Although a rectal carcinoma was suspected based on the finding of PET/CT and CEA, the histopathological examination confirmed the diagnosis of the malignant GIST of the rectum. The patient was then treated with imatinib and on follow-up regularly. In this case, ¹⁸F-FDG PET/CT shows the advantage of visualizing both primary and metastatic lesions and provides valuable information for the diagnosis, staging, evaluation, and prognosis of GIST.

Bone Metastases of Gastrointestinal Stromal Tumor: A Review of Published Literature

Background

With the occurrence and improvement of immunohistochemistry and other pathological diagnostic techniques, gastrointestinal stromal tumor (GIST) has been gradually recognized. With the prolonged survival of patients with GISTs, reports about the bone metastasis of GIST increased. However, the knowledge of GISTs is rather limited due to its very low incidence.

Methods

Cochrane and Medline database (via PubMed) were searched in July 2019 with related keywords to acquire the literature related to the bone metastasis of GIST. Then, the literature was reviewed and references were also scanned to identify the possible related reports. Study data comprising age, sex, primary location, metastasis interval time, immunohistochemistry index, management and prognosis were recorded and analyzed.

Results

Forty-five patients with bone metastases of GIST, with a mean age of 61.09 years, were included. The small intestine and stomach were the most common primary sites, followed by the rectum. Patients with small intestine primary sites had bone metastases that occurred earlier than the bone metastases stomach and rectum primary sites. The spine was the most common site of bony metastases. The mean survival time after GIST diagnosis was more than 64.02 months. Patients younger than 60 years old had a worse prognosis than those older than 60 years old. Furthermore, patients with spinal involvement had a worse prognosis than those without spinal involvement. Surgical interventions combined with targeted therapies guaranteed a better prognosis.

Conclusion

Bone metastasis of GIST, which mainly occurs in the spine, is rather rare. Patients with GISTs of the small intestine and stomach suffered from bone metastasis more frequently and earlier than patients with GISTs in other primary sites. Age, sex, primary tumor location, treatment mode for the primary lesions and metastases, and spine involvement may be potential factors that affect the prognosis of GIST patients with bone metastases.

Long-Term Survival After Multidisciplinary Treatment Including Surgery for Metachronous Metastases of Small Intestinal Gastrointestinal Stromal Tumors after Curative Resection: A Case Report

Patient: Male, 56-year-old

Final Diagnosis: Metachronous metastases of small intestinal gastrointestinal stromal tumors

Symptoms: Abdominal and/or epigastric pain

Medication: —

Clinical Procedure: Operation • chemotharapy

Specialty: Gastroenterology and Hepatology

Clinical and pathological characteristics of gastrointestinal stromal tumor (GIST) metastatic to bone

Our aim in this study was to describe the clinical, morphological, and molecular profile of gastrointestinal stromal tumor (GIST) metastatic to bone. We analyzed the morphological, phenotypic, and molecular characteristics of seven cases, and in addition reviewed 17 cases from literature. Sequence analysis of KIT and PDGFRA genes was possible for six cases. For the GIST cases with bone metastasis, the most common primaries were small intestine (29%), stomach (25%), and rectum (21%). Sites of bone metastases were vertebrae (11), pelvis (8), femur (8), ribs (6), humerus (5), skull (3), scapula (1), and mandible (1). The size ranged from 1.5 to 13 cm (median, 3.8 cm). Bone metastases without involvement of any other organ were seen in 17% of the cases and were solitary in 14 (58%). Adjacent soft tissue involvement was present in nearly half of the patients. Bone metastasis was either manifest at the time of diagnosis (28%) or occurred after a mean period of 4.7 years (3 months-20 years). Morphologically, neoplastic cells were spindle in 67%, epithelioid in 13%, and mixed epithelioid and spindle in 20%. CD117, DOG1, and CD34 were positive in 88, 86, and 85% of the cases, respectively. KIT Exon 11 mutations were the most frequent gene alteration (78%), followed by KIT Exon 13 mutations. Of 17 of the cases with available follow-up information, 7 (41%) patients developed bone metastasis under imatinib therapy. Five patients (29%) died of disease within a mean of 17 months. Bone metastases from GIST are usually found in patients with advanced disease and typically present as lytic masses with occasional soft tissue involvement. We could not identify any KIT or PDGFRA alterations predisposing to bone metastasis.

Gastrointestinal Stromal Tumour with Synchronous Bone Metastases: A Case Report and Literature Review

Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours of the digestive tract, derived from Cajal interstitial cells. Bone metastases are very rare, and there is no consensus regarding their treatment. Here, we present the unusual case of a 66-year-old man with a gastric GIST with synchronous bone and liver metastases, fully documented at the pathological and molecular levels with a KIT exon 11 mutation. After 9 months of imatinib, the scanner showed a 33% partial response of target lesions. We also review the literature and describe the characteristics, treatment, and outcome of all cases previously reported.

Bone metastasis in gastrointestinal stromal tumors preferentially occurs in patients with original tumors in sites other than the stomach

Bone metastases are rare in gastrointestinal stromal tumors (GISTs) and data on the clinicopathological profiles are lacking. The purpose of this report was to identify the clinicopathological profiles of this rare clinical setting by evaluating 23 cases, four of which were our own and the additional 19 were from the relevant English literature. In 18 cases, the primary GISTs occurred in sites other than the stomach, although a high proportion of these tumors do arise in the stomach. All tumors at the disease presentation had more than a low risk of recurrence, with most tumors either at a high risk or initially malignant with liver metastasis. In four cases, bone metastasis was the primary metastatic manifestation. Although rare in GISTs, bone metastasis should be considered in patients with primary tumors at a high risk for recurrence or in initially malignant tumors with liver metastasis, especially with primary tumors in sites other than the stomach.

Bone metastasis of a gastrointestinal stromal tumor: A report of two cases

Gastrointestinal stromal tumors (GISTs) are the most frequently diagnosed mesenchymal tumors of the GI tract. GISTs usually arise from the stomach, followed by the small intestine, rectum and other locations in the GI tract. The most common metastatic sites are the liver and peritoneum, whereas GISTs rarely metastasize to the bone. Although a small number of previous studies have described bone metastases originating from GISTs, the true prevalence is yet to be elucidated. The present study describes two cases of bone metastasis in patients with GISTs and reviews the relevant literature. Case one was of a 78-year-old male who presented with bone metastasis to the femoral neck five years after the resection of a GIST. The metastasis was completely resected and the patient remains alive nine years after the initial diagnosis of the GIST. Case 2 was of a 41-year-old male who presented with bone metastases to the ribs following resection of GISTs seven and 17 years earlier. The metastases were completely resected and the patient remains alive 17 years after the initial diagnosis. In total, only 10 cases of GISTs with metastases to the bone have been reported in the English literature. The possibility of bone metastases originating from a GIST should be considered during clinical follow-up, particularly in the presence of liver metastases. If feasible, bone metastases should be completely surgically excised.