Gastrointestinal stromal tumors (GISTs) are rare in pregnancy, with only 11 reported cases. Adjuvant imatinib therapy, which targets the most common driver mutations in GIST (KIT and PDGFRA), is recommended for patients with high-risk GIST, but it has known teratogenicity in the first trimester. A 34-year-old G3P2 woman underwent exploratory laparotomy at 16 weeks' gestation for a presumed adnexal mass. Surgical findings included normal adnexa and a 14-cm solid small bowel mass. The mass was resected en bloc with a segment of jejunum followed by a primary anastomosis. Histopathology and genomic analyses demonstrated a GIST with high-risk features but lack of KIT/PDGFRA mutations and identified the presence of a previously unreported, pathogenic PRKAR1B-BRAF gene fusion. Given her tumor profile, adjuvant therapy with imatinib was not recommended. GIST is rare in pregnancy, but can masquerade as an adnexal mass in women of childbearing age. Because neoadjuvant/adjuvant imatinib has risks of teratogenicity, tumor molecular profiling is critical as we identified a previously unreported gene fusion of PRKAR1B with BRAF that is predicted to be imatinib-resistant. In this case, testing provided the rationale for not offering adjuvant imatinib to avoid unnecessary toxicity to the patient and fetus.
Lindsey M. Charo, Adam M. Burgoyne, Paul T. Fanta, Hitendra Patel, Juliann Chmielecki, Jason K. Sicklick and Michael T. McHale
Al B. Benson III, Alan P. Venook, Mahmoud M. Al-Hawary, Mustafa A. Arain, Yi-Jen Chen, Kristen K. Ciombor, Stacey A. Cohen, Harry S. Cooper, Dustin A. Deming, Ignacio Garrido-Laguna, Jean L. Grem, Sarah E. Hoffe, Joleen Hubbard, Steven Hunt, Ahmed Kamel, Natalie Kirilcuk, Smitha Krishnamurthi, Wells A. Messersmith, Jeffrey Meyerhardt, Eric D. Miller, Mary F. Mulcahy, Steven Nurkin, Michael J. Overman, Aparna Parikh, Hitendra Patel, Katrina S. Pedersen, Leonard B. Saltz, Charles Schneider, David Shibata, John M. Skibber, Constantinos T. Sofocleous, Elena M. Stoffel, Eden Stotsky-Himelfarb, Christopher G. Willett, Alyse Johnson-Chilla, Kristina M. Gregory and Lisa A. Gurski
Small bowel adenocarcinoma (SBA) is a rare malignancy of the gastrointestinal tract that has increased in incidence across recent years. Often diagnosed at an advanced stage, outcomes for SBA are worse on average than for other related malignancies, including colorectal cancer. Due to the rarity of this disease, few studies have been done to direct optimal treatment, although recent data have shown that SBA responds to treatment differently than colorectal cancer, necessitating a separate approach to treatment. The NCCN Guidelines for Small Bowel Adenocarcinoma were created to establish an evidence-based standard of care for patients with SBA. These guidelines provide recommendations on the workup of suspected SBA, primary treatment options, adjuvant treatment, surveillance, and systemic therapy for metastatic disease. Additionally, principles of imaging and endoscopy, pathologic review, surgery, radiation therapy, and survivorship are described.