Gastrointestinal Stromal Tumors: A “Benign” Tumor with Hepatic Metastasis after 11 Years

Abstract

Gastrointestinal stromal tumors (GIST) constitue the largest category of primary non-epithelial neoplasms of the stomach and small bowel. They are characterized by a remarkable cellular variability and their malignant potential is sometimes difficult to predict. Very recent studies, using mitotic count and tumor size as the best determinants of biological behavior, divide GISTs into three groups: benign, borderline and malignant tumors. We report on a male patient who underwent a right hepatectomy for a large metastasis 11 years after the surgical treatment of an antral-pyloric gastric neoplasm, histologically defined as leiomyoblastoma and with clinical, morphological and immunohistochemical features of benignity (low mitotic count, tumor size < 5 cm, low cellular proliferation index). Histological and immunohistochemical analysis of the hepatic metastasis showed the cellular proliferation index (Ki-67) to be positive in 25% of neoplastic cells, as opposed to the primary gastric tumor in which Ki-67 was positive in only 5% of neoplastic cells. In conclusion, although modern immunohistochemical techniques are now available to obtain useful prognostic information, the malignant potential of GISTs is sometimes difficult to predict: neoplasms clinically and histologically defined as benign could metastasize a long time after oncologically correct surgical treatment. Therefore, benign GISTs also require consistent, long-term follow-up.

Prognostic value of KIT mutation in gastrointestinal stromal tumors

“…GISTs are the most common mesenchymal tumors of the human gastrointestinal tract which are enigmatic in terms of their line of differentiation or cell of origin and clinical behavior [5] . Recently, many studies have shown that tumor size, location, mitotic cell count, cell type, proliferative activity, presence of necrosis, presence of hemorrhage, microscopic invasion to adjacent tissues, recurrence, distant metastasis, as favorable factors of GIST.…”

Biological Significance of Chromosomal Imbalance Aberrations in Gastrointestinal Stromal Tumors

“…However, they do not always reliably predict patient outcomes. Therefore, the designation, 'uncertain malignant potential', applies to a significant number of GISTs; close follow-up is needed in such cases [1,8,18,25]. Recently, some studies suggested that the disease-free survival of patients with c-kit mutation-positive GISTs was poorer than those with c-kit mutation-negative GISTs [22,24].…”

Cutaneous Metastases from a Gastrointestinal Stromal Tumor of the Stomach: Review of Literature

“…In a study of 50 malignant GIST, the survival was 84% at 1 year, 51% at 3 years and 41% at 5 years [4]. In general, it is difficult to predict the malignant potential and recurrence rate of GIST, hence long-term follow-up is essential [13]. …”