Gastrointestinal Stromal Tumors: A Review of the Literature

Abstract

Gastrointestinal stromal tumors are mesenchymal neoplasms with a spectrum of histologic appearances and biologic activity. The morphologic classification of these lesions has evolved over time, and molecular analysis has led to a better understanding of their nature. The histologic differential diagnosis for these lesions is broad and includes many spindle cell lesions of the gastrointestinal tract, including neoplasms of true smooth muscle and neural origin, proliferating fibrous lesions, metastatic neoplasms, and primary sarcomas of vascular and adipose origin. Immunohistochemical studies that include CD117 have become invaluable in the classification of mesenchymal lesions arising in the gastrointestinal tract. Treatment of gastrointestinal stromal tumors has historically been involved surgery, but the use of the chemotherapeutic agent imatinib mesylate for advanced disease has made accurate classification even more important. The molecular features have not only allowed us to understand the pathogenesis of these tumors but also have proven to be associated with response to kinase inhibitors.

Primary Adrenal Gastrointestinal Stromal Tumor (GIST): a Rarest Incidentaloma and Diagnostic Challenge

“…Gastrointestinal stromal tumors (GISTs) are known to arise from interstitial cells of Cajal which are specialized cells in the autonomic nervous system of the intestine [3]. Commonly, GISTs are seen within the stomach although they can be present anywhere along the gastrointestinal tract.…”

Gastrointestinal Stromal Tumor

“…En la actualidad, el diagnóstico y estadificación de estos tumores se realiza por estudio ultraestructural e inmunohistoquímico (18) , ya que desde el punto de vista histológico se debe hacer un diagnóstico diferencial con otros tumores no epiteliales del tracto gastrointestinal, como tumores del músculo liso, tumores desmoides, schwannomas, tumores fibrosos solitarios, pólipos inflamatorios, tumores metastásicos y sarcomas primarios, como melanoma maligno, angiosarcoma y el liposarcoma (19,20) . Se ha determinado, con el uso de anticuerpos monoclonales, que aproximadamente 95% de los TEG expresan la proteína CD117, también denominada proteína KIT, mientras que la expresión de CD34 ocurre en 60 a 70% de estos tumores.…”

“…Aproximadamente 30% de los TEG son positivos para actina de músculo liso (SMA) y un porcentaje menor lo es para desmina. También pueden resultar positivos para nestina y vimentina, aunque son negativos para la proteína acídica fibrilar glial, lo que los diferencia de los schwannomas (20)(21)(22)(23) . La muestra tomada en el presente caso resultó fuertemente positiva para CD117, CD34 y vimentina, con lo cual se confirmó el diagnóstico de TEG.…”

Gastrointestinal Stromal Tumor – An Overview

“…Some tumors are predominantly extramural and extremely large tumors may even extend to or infiltrate into the adjacent organs. On cut sections, the tumors are gray-white and solid with a fleshy appearance and often show hemorrhage, necrosis, or cystic change [25] • Microscopic features -GI stromal tumors are very cellular lesions, with 70% of cases composed of spindle cells, 20% of epithelioid cells, and the remainder having a mixed cellular composition. Depending on the cytological features including cellularity, nuclear atypia, mitosis, and necrosis, they can be further categorized into potentially benign and malignant GIST.…”