GIST gástrico complicado. Una forma de presentación inusual / Complicated gastric GIST. An unusual presentation

RESUMEN Los tumores GIST son un motivo de consulta cada vez más frecuente en las entrevistas de cirugía gastroenterológica. Suelen ser derivados como hallazgos incidentales o por presentar síntomas derivados de su crecimiento. Se presenta el caso clínico de una paciente que requirió internación de urgencia por síndrome anémico agudo. Se comenta su algoritmo diagnóstico y su resolución quirúrgica. Asimismo se comentan los estándares de diagnóstico y tratamiento actuales con especial foco en la estrategia quirúrgica, la cual debe ser individualizada según cada caso.

ABSTRACT Gastrointestinal stromal tumors (GISTs) are becoming an increasingly common reason for consultation in gastroenterology surgery interviews. Patients are usually referred for surgery due to an incidental finding or symptoms associated with tumor growth. We report the case of a female patient who required urgent hospitalization due to acute anemic syndrome. The diagnostic algorithm and surgical approach are described. The current standards of diagnosis and treatment are also discussed, with special focus on the surgical strategy, which must be tailored to each case.

Desarrollo de resistencia secundaria a imatinib y tratamiento quirúrgico de un GIST gástrico maligno / Secondary imatinib resistance and surgical treatment of a malignant gastric GIST

Introduction. Gastrointestinal stromal tumors (GIST) constitute a pathological condition whose treatment require the interaction of surgical and pharmacological procedures in primary, recurrent, and metastatic disease. Herein, we discuss the case of a patient operated for malignant primary GIST who suffered recurrence of his disease secondary to the development of imatinib resistance. Case report: A male patient was operated on March 2007 because of a malignant gastric GIST, with wedge resection of the tumor. In June 2008, a computerized abdominal tomography scan (CT) showed the presence of nodules over the porta hepatis, mesocolon, greater omentum and gastric antrum; at this moment imatinib 400 mg/day was initiated. A new CT in June 2010, showed a cystic tumor in the right lower abdominal quadrant besides the previously described peritoneal implants, and surgical treatment was proposed. The surgical findings consisted on a big cystic GIST implanted over the greater omentum, and multiple epiploic nodules over the gallbladder and gastric antrum. All visible tumors were resected including the gallbladder and gastric antrum. A positron emission tomography taken on December 2010, described 2 small hypermetabolic peritoneal nodules. The imatinib dose was increased to 800 mg/day, and at the last control, one year after the last surgery, the CT did not show disease progression. Discussion: This case report illustrates the GIST’s malignant potential. The tumor developed imatinib resistance after an initial period of good response to the drug. To control the disease, a new surgical intervention and an increase in the dose of imatinib was required.

Introducción. Los tumores del estroma gastrointestinal (GIST) constituyen una condición patológica cuyo tratamiento requiere la interacción de procedimientos terapéuticos y farmacológicos en los tumores primarios, recurrencias y metástasis. Reportamos el caso de un paciente operado por un GIST primario que sufrió recurrencia secundaria a desarrollo de resistencia al imatinib. Caso clínico: Paciente que se operó en marzo de 2007 por un GIST gástrico maligno, realizándose resección en cuña del tumor. En junio de 2008, como parte del seguimiento, se tomó una tomografía abdominal que informó la presencia de nódulos en el hilio porta, mesocolon, epiplón mayor y antro gástrico, iniciándose tratamiento con imatinib 400 mg diarios. La tomografía realizada en junio de 2010 demostró en el hemiabdomen derecho un tumor quístico, además de los implantes previamente descritos. Con estos antecedentes se decidió el tratamiento quirúrgico. Los hallazgos consistieron en un GIST del epiplón mayor, múltiples lesiones epiploicas, vesiculares y del antro gástrico. Se decidió resecar todas las lesiones visibles, la vesícula biliar y el antro gástrico. Una tomografía por emisión de positrones de diciembre de 2010 describe 2 pequeños nódulos hipermetabólicos peritoneales. Se aumentó la dosis de imatinib a 800 mg diarios y en el último control a 1 año de la última cirugía, la tomografía no demostró progresión de la enfermedad. Discusión: El presente caso ilustra el potencial maligno de los GIST. El tumor desarrolló resistencia al imatinib después de un período inicial con buena respuesta. Para controlar la enfermedad se requirió una nueva intervención quirúrgica y aumento de la dosis de imatinib.

Effect of Imatinib Mesylate in Recurrent Gastric GIST

PURPOSE: Gastrointestinal stromal tumor (GIST) is the designation for c-kit signal driven mesenchymal tumor. A great majority of these tumors occur in the stomach and small intestine, and rarely in the colon, rectum and esophagus. Metastatic or recurrent GIST must be resected surgically because it is resistant to conventional cytotoxic chemotherapy. Following recent evidence for the dramatic effect of Imatinib mesylate (Glivec), Glivec has become available in our country since June 2001 without insurance coverage. Although some doubt remained, we applied Glivec to recurrent GIST patients with great expectation. METHODS: A retrospective analysis was made for 16 GIST patients who were resected during 2001. Follow up duration was 19 to 29 months. All pathologic slides were reexamined immunohistochemically by an experienced pathologist. Clinicopathologic comparison between the recurred and non-recurred groups was summarized into the tables. The therapeutic and side effects of Glivec were surveyed. CT scan files were reviewed to decided tumor regression or progression. RESULTS: Fifteen GISTs were resected in 2001. Seven cases recurred during 19 to 29 months of follow up. The recurred group was characterized by huge tumor size (mean 14 cm), serosal invasion and more than 10 mitosis in 50 HPF. A daily dose of 400 mg of Glivec was prescribed to every recurred GIST patients and CT scan was followed serially. The therapeutic effect of Glivec effect was drastic but variable; complete tumor remission (n=3), rebounded tumor growth at the same location after remission (n=1), and recurrence at another location after complete remission (n=2). CONCLUSION: Glivec drastically reduced the size of recurrent gastric GIST initially. However, it is not clear how long Glivec should be taken at a great expense in fear of rebounded growth after abstaining. It appears that reoperation is necessary without delay when tumor remission slows down.