Malignant gastrointestinal neuroectodermal tumor: A case report and review of the literature

Abstract

Malignant gastrointestinal neuroectodermal tumor (GNET) is a rare soft tissue sarcoma, previously referred to as clear cell sarcoma-like gastrointestinal tumor (CCSLGT) and also commonly reported in the literature as clear cell sarcoma of the gastrointestinal tract (CCS-GI). The current study reports a case of GNET arising in the stomach of a 17-year-old male, who presented with symptoms of fatigue, anemia and low temperature. Examination with positron emission tomography-computed tomography revealed a soft tissue mass in the gastric antrum. Subsequently, radical distal gastric resection was performed, and the mass measured 6.0×4.0×3.5 cm3. Histopathological analysis revealed that the tumor cells were arranged in nests and focally formed fascicular, pseudopapillary, pseudoalveolar and rosette-like growth patterns. Osteoclast-like giant cells were also observed. Immunohistochemically, the tumor cells were positive for S-100 protein, vimentin and BCL-2, and negative for HMB45, Melan-A, CD117, CD34 and CD99. Additionally, the osteoclast-like giant cells were positive for CD68. Fluorescence in situ hybridization demonstrated EWSR1 gene rearrangement. After 10 months of follow-up, no evidence of recurrence or metastasis was observed. As GNET is currently classified differently and under various names in the literature, the information provided by this case study and review is predicted to be useful towards the accurate diagnosis, treatment and prognosis of this rare tumor type.

Malignant gastrointestinal neuroectodermal tumour of the oesophagus with pulmonary metastasis and protracted survival

“…The distinctive morphology and positivity for S100 and focal neuroendocrine markers in the absence of expression of specific markers of melanocytic differentiation are typical of the relatively recently described GNET . These neoplasms characteristically have rearrangements of the EWSR1 gene, with t(12;22)(q13;q12) EWSR1–ATF1 or t(2;22)(q34;q12) EWSR1–CREB1 fusions, similar to those of clear cell sarcoma (CCS) of tendons and aponeuroses .…”

“…GNET, a very rare neoplasm that occurs predominantly in young adults, has been described predominantly in the small bowel, stomach, and colon. It has been reputed to be an aggressive tumour with a propensity for local recurrence and for lymph node and liver metastasis . Historically, GNET has been classified under the designation CCS, owing to similarities in their morphological, immunophenotypic and genetic profile .…”

Indolent Gastrointestinal Neuroectodermal Tumor (GNET) of the Colon: A New Entity?

“…As a general rule, GNET follows aggressive clinical behavior with death from disease in the majority of patients. Indeed, about half of the patients already have lymph node involvement, and some also metastatic disease (liver or lung), at the time of diagnosis [12]. GNET affects both young and old patients with no gender preference.…”

“…With less than 50 cases reported in the English language literature, GNET is now recognized as a rare neoplasm that predominantly arises from the small intestine [10,11], followed by the stomach [12], esophagus [13], and the colon [14]. Patients commonly complain of abdominal pain and weight loss, and some also experience fever, anemia, and melena [7,12]. GNET is usually treated by surgical excision, followed by chemotherapy if metastatic disease is present [11].…”

“…GNET is usually treated by surgical excision, followed by chemotherapy if metastatic disease is present [11]. Indeed, almost half of the patients showed lymph node involvement at the time of diagnosis, and many had metastatic liver disease [12]. For esophageal GNET, pulmonary metastasis was also reported [15].…”