P1993 - Massive Intra-Abdominal Mass in a 58-Year-Old Patient

Spyridon Zouridis, MD, Muhammad Farhan Ashraf, MD, Rizwan Jattala, MD, Drinnon Hand, MD
Albany Medical Center, Albany, NY

Introduction: Intra-abdominal mass is a finding often encountered in clinical practice. The differential diagnosis of an intra-abdominal mass is very broad including traumatic lesions, vessel abnormalities, renal pathology, benign tumors, invasive malignancy, and other entities. Even though many patients are diagnosed incidentally, some will have progressed disease, leading to signs/symptoms secondary to mass burden and compression effects. Here we will present a neglected rare mesenchymal neoplasm case.

Case Description/Methods: FM, a 58-year-old man without significant medical history other than heavy smoking presented with abdominal distention, constipation, incontinence, hematochezia, rectal prolapse and progressive severe LE edema. Interestingly, 10 years ago an “abdominal mass” was detected incidentally but the patient never sought medical attention for appropriate work-up. A CT of the abdomen and pelvis revealed a large intra-abdominal mesenteric mass, 30x25x20 cm, without evidence of bowel obstruction or hydronephrosis. Biopsy of the lesion showed high grade spindle cell gastrointestinal stromal tumor (GIST), likely arising from omentum or terminal ileum. Further work-up revealed no metastatic disease and patient underwent surgical excision of the 24-pounds mass along with en-bloc mid ileum resection and left hemicolectomy. Biopsy further characterized the surgically excised mass as liposarcoma arising from colon. Post-operatively patient developed ileus, resolved with conservative management but otherwise his course was uneventful, and patient scheduled to follow up with oncology services for Imatinib therapy.

Discussion: GIST are relatively rare mesenchymal tumors. Usually, they are detected incidentally but, in some cases, they may grow causing non-specific symptoms such as early satiety and bloating, while in rare cases, tumors may grow large enough to cause severe symptoms (compression effects, pain, bowel obstruction, GI bleeding). Initial evaluation includes screening for metastatic disease with CTAP or PET, while for large tumors ( ≥2cm) chest imaging is also indicated. Assessment of mutations is also suggested by literature. Response to systemic therapy, like Imatinib, correlates with better outcomes in GIST with specific gene mutations such as KIT. Prognosis is variable depending on tumor characteristics like tumor size and mitotic index while the primary tumor location is also important to predict disease outcome.



Disclosures:


Spyridon Zouridis, MD, Muhammad Farhan Ashraf, MD, Rizwan Jattala, MD, Drinnon Hand, MD. P1993 - Massive Intra-Abdominal Mass in a 58-Year-Old Patient, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.