Congenital gastrointestinal stromal tumour is morphologically indistinguishable from the adult form, but does not express CD117 and carries a favourable prognosis

Neonatal Gastrointestinal Stromal Tumor of the Sigmoid Colon: A Case Report and Review of Literature

ABSTACTBackground: Gastrointestinal stromal tumors (GIST) are the most common mesenchymal neoplasms of the digestive tract. They are believed to originate from the interstitial cells of Cajal or their precursors. Case Report: A 10-day-old boy presented with intestinal obstruction. He was operated upon and a mass was found at the sigmoid colon, which was resected and divided colostomy was performed. The diagnosis of neonatal GIST was confirmed by histologic and immunohistochemical studies. Conclusion: This is the ninth case of neonatal GIST that arose from the intestine and the first reported to arise from the sigmoid colon. Colonic GIST can occur in the neonatal age group.

Gastrointestinal stromal tumor in a newborn diagnosed in prenatal period: a case report and review of literature

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Only 1.5% to 2% of all GISTs are observed in children and adolescents. Most of the pediatric cases are between 10 and 18 years of age, with a median age of 13 years. GIST is extremely rare in the newborn period. We could find only 5 reports on the neonatal cases. Herein, we have reported a case with abdominal tumor that was identified by prenatal ultrasonography and magnetic resonance imaging, and diagnosed as GIST on the seventh day of life. We have also reviewed the neonatal GIST cases reported in the English literature.

Soft tissue tumors of uncertain origin

Many soft tissue tumors of childhood lack obvious differentiation toward a defined mesenchymal tissue type or have a phenotype that does not correspond to any defined normal tissue. These challenging tumors are currently regarded as neoplasms of uncertain differentiation. Nonetheless, there have been great strides in the understanding of their pathologic and genetic features and biologic underpinnings. The application of new genetic information to the pathologic diagnosis among this group of tumors is an emerging area in diagnostic pediatric pathology. This article reviews the clinicopathologic features of tumors of uncertain and/or miscellaneous origin, with an emphasis on the unique aspects of these neoplasms in children and adolescents, use of diagnostic adjuncts, and differential diagnosis.

A rare cause of intestinal obstruction: neonatal gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are rare in the childhood period. The authors reported a case who was admitted to the neonatal intensive care unit (NICU) on a suspicion of intestinal obstruction. She was operated and a mass in a size of 6 x 4.5 x 4 cm was resected from the ileum. Histologic and immunohistochemical studies showed a GIST. CD34, small muscle actin (SMA), and desmin were positive. The baby was discharged on the 13th day after operation.

Gastrointestinal stromal tumors of the small intestine in pediatric populations: a case report and literature review

An 18-year-old girl presented with abdominal pain and a tumor was subsequently detected in the jejunum. We therefore carried out a wedge resection of the jejunum. The diagnosis of GIST was confirmed histologically, and a mutation in exon 9 of the c-kit gene was observed. GISTs are rare in pediatric populations and pediatric GISTs occur predominantly in females and are characterized by a multifocal gastric location and a wild-type phenotype for the c-kit genes. The features of pediatric GISTs of the small intestine have not yet been categorized, and to date, only 11 cases in patients younger than 18 years have been reported. These cases did not occur primarily in females and tended to present as single tumors with mutations in the c-kit gene. This suggests that these cases do not have the same features as pediatric gastric GISTs, but instead are similar to adult GISTs. In pediatric populations, GISTs of the small intestine were expected to show a better response to imatinib treatment than gastric GISTs because of the alterations in the c-kit gene.

Gastrointestinal stromal tumors (GIST) in children and adolescents: A comprehensive review of the current literature

Standards for the management of gastrointestinal stromal tumors (GIST) in children do presently not exist. Thus a systematic review and summary of the current literature was conducted serving as a basis for the further development of optimal management strategies for childhood GIST within a cooperative network. Presently 21 cases with familial GIST, and more than 100 pediatric cases each with Carney triad or sporadic GIST have been published so far. An international prospective registration based on national registries has recently started to acquire more clinical and molecular data and to develop appropriate management strategies for children and adolescents with GIST.

Pediatric gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) rarely occur in pediatric patients, but increased recognition of adult GIST has led to better awareness of the existence of this entity in the pediatric population. GIST occurring in pediatric patients has a unique biology and clinical behavior and warrants discussion as an independent entity. The generally accepted definition of pediatric GIST is a tumor that is diagnosed at the age of 18 years or younger. This review highlights the clinical features, molecular biology, and clinical management of this rare pediatric entity.

[Gastrointestinal stromal tumors: definition, histological, immunohistochemical, and molecular features, and diagnostic strategy]

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract. Major advances in their definition and classification and the understanding of their molecular mechanisms have recently been made. These advances have resulted in the delineation of a treatment that has become a model of targeted therapy in oncology. GISTs are defined as tumors of the gastrointestinal tract, but also of the mesentery and peritoneum, constituted by a proliferation of usually spindle-shaped, rarely epithelioid cells, usually, but not consistently expressing the KIT protein. Most GISTs are associated with molecular abnormalities in two target genes: KIT (which encodes the KIT protein) and PDGFRA (which encodes the A chain of the PDGF receptor). The diagnosis of GIST relies on histological arguments (proliferation of spindle-shaped cells in 70% of cases, of epithelioid cells in 20%; histological variants are rare and sometimes misleading) and on immunohistochemical arguments (expression of KIT in 95%, usually associated with CD34 expression in 60%-70% of cases). The demonstration of mutations in target genes is required only in cases that are histologically suggestive but KIT-negative; beyond this indication, this is only undertaken in research protocols. The differential diagnosis of GIST includes the other mesenchymal tumors of the gastrointestinal tract, such as leiomyomas and leiomyosarcomas, and the digestive locations of some sarcomas; it relies on both histological and immunohistochemical arguments. The evaluation of the prognosis is essential. According to the current concept, every GIST carries a risk of malignancy, which may vary from very low to very high. Prognosis is based on a simple algorithm using two histoprognostic parameters, i.e., tumor size and mitotic index. The treatment of localized GIST is surgical resection, which must be complete; that of advanced or unresectable GIST is based on the use of a targeted therapy, imatinib, which is a pharmacological antagonist of the KIT protein. Proper understanding and utilisation of the diagnostic criteria and classification of GIST by pathologists are essential for good patient management.

Advanced-stage gastrointestinal stromal tumor treated with imatinib in a 12-year-old girl with a unique mutation of PDGFRA

A 12-year-old girl presented with a large abdominal tumor. At surgery, a huge pedunculated extraluminal tumor was found arising from the greater curvature of the stomach and invading the surrounding structures, and there were also a submucosal tumor measuring 5 x 4 x 4 cm and multiple intramural nodules beside the main tumor. These lesions, which were removed with 1.0-cm surgical margins, were immunohistochemically positive for c-kit (CD117) and CD34. A diagnosis of gastrointestinal stromal tumor (GIST) was made. The huge size of the tumor (3.6 kg in weight and 36 x 25 x 25 cm in diameter), the invasion of the surrounding structures, and the increased mitotic figures indicated the GIST had malignant potential. Sequence analysis of the polymerase chain reaction product of RNAs from the tumor cells revealed a novel platelet-derived growth factor receptor alpha (PDGFRA) mutation, which would exhibit biologic consequences similar to those of the c-kit mutation. The patient underwent a 3-month course of imatinib mesylate as adjuvant chemotherapy because of the possible risk for tumor recurrence. She is now doing well without any evidence of recurrence or metastasis 25 months after the surgery. Only 9 cases of GIST have been reported in children, and a review of those cases revealed GISTs in children would be associated with a better prognosis than in adults and that one third of pediatric GISTs presented with intestinal obstruction in the newborn period.

Gastrointestinal stromal tumors in children and young adults: a clinicopathologic, molecular, and genomic study of 15 cases and review of the literature

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the intestinal tract that typically occur in adults over the age of 40 years. GISTs in younger patients are rare and not well characterized. The objective was to define the characteristics of GISTs in children and young adults (<30 years old). Clinicopathologic and molecular features, including KIT/PDGFRA genotype, in GISTs from 5 children and 10 young adults were analyzed. Gene expression analysis was performed on 5 gastric tumor samples from 2 children, 2 gastric tumors from young adults, and 10 gastric GISTs from older adults using an U133A Affymetrix platform (22,000 genes). All five pediatric GISTs occurred in girls, involved the stomach as multiple nodules, showed predominantly an epithelioid morphology, often involved lymph nodes, and lacked KIT or PDGFRA mutations. Although all five patients developed recurrence (four in the liver, three in the peritoneum, and two in both sites), four are still alive with disease. Of the 10 GISTs in young adults, half occurred in the small bowel and had spindle cell morphology, and one case had lymph node metastasis. KIT mutations were identified in seven cases, four in exon 11 and three in exon 9. Seven patients developed recurrence, and at last follow-up two patients had died of disease. Gene expression analysis showed high expression of PHKA1, FZD2, NLGN4, IGF1R, and ANK3 in the pediatric and young adult versus older adult cases. GISTs that occur in children are a separate clinicopathologic and molecular subset with predilection for girls, multifocal gastric tumors, and wild-type KIT/PDGFRA genotype. In contrast, GISTs in young adults are a more heterogeneous group, including cases that resemble either the pediatric or the older adult-type tumors. The distinct gene expression profile suggests avenues for investigation of pathogenesis and potential therapeutic strategies.

Neonatal gastrointestinal stromal tumor. Report of a case and review of literature

Gastrointestinal stromal tumor (GIST) is very rare in infancy. Most of the reported cases in the literature are in adults; some are in children but there are a few reported cases in the literature. The present case is a 6-day-old female neonate presenting with lethargy, poor feeding, constipation, abdominal distention, and rectal bleeding. She was operated on with the impression of intestinal obstruction, and right hemicolectomy was performed on her. Surgical specimen showed a well-defined and round 3-cm mass in the cecal area. Diagnosis was made by histologic and immunohistochemical studies which showed a GIST. The tumor showed positive vimentin and c-kit but negative for all other markers (desmin, actin, S100, NSE, and CD-34). So the case was an undifferentiated GIST. After 1 year of follow-up the patient was completely normal.

Tumeur stromale gastro-intestinale chez l’enfant

Stromal gastrointestinal tumors or GIST are undifferentiated mesenchymal tumors of gastrointestinal tract that showed characteristic c-kit expression. GIST are very rare in children and only 21 cases are reported in literature. The authors present a GIST arising in the stomach of a 7-year-old girl and revealed by severe anaemia. The patient underwent surgical resection and chemotherapy because of high-risk markers. Positive diagnosis and prognosis of paediatric GIST are discussed with literature data.

Pediatric gastrointestinal stromal tumors and leiomyosarcoma

BACKGROUND

With the introduction of molecularly targeted therapy for gastrointestinal stromal tumors (GISTs), it became important to distinguish GISTs from leiomyosarcomas (LMSs). The authors sought to characterize the clinicopathologic features of these tumors in pediatric patients.

METHODS

The authors reviewed the medical records of 11 patients for whom GIST or LMS was diagnosed between March 1962 and July 2002 at St. Jude Children's Research Hospital and reclassified the tumors according to current histologic and immunophenotypic criteria. The authors also reviewed the literature pertaining to pediatric GISTs and LMSs.

RESULTS

Seven patients had GISTs, and four had LMS. The median age of the patients at diagnosis was 11.5 years. At diagnosis, metastases were present in one patient with GISTs and in another with LMS. Unlike the focal distribution of CD117 (KIT) in LMS, diffuse and strong immunostaining was observed in GISTs. Only GISTs expressed CD34. Six patients underwent complete resection (four with GISTs and two with LMS), four patients underwent incomplete resection (three with GISTs and one with LMS), and one patient (with LMS) underwent a biopsy only. Radiotherapy or chemotherapy was used to treat one patient with GISTs and three patients with LMS. One patient with a high-risk GIST (largest dimension of 32 cm and high mitotic count) was treated with adjuvant imatinib mesylate outside the preferred setting of a clinical trial, due to concerns regarding the high risk of tumor recurrence. Four patients with GISTs and two with LMS survived median disease-free a median of 10.4 years and 4.3 years after diagnosis, respectively. Tumors in all but one survivor were completely resected.

CONCLUSIONS

KIT staining helped to distinguish GISTs from LMSs. Surgery was the treatment of choice for both entities, and tumor resectability was a key prognostic factor.

Malignant stromal tumor of the colon in an infant: diagnostic difficulties and differential diagnosis

Gastrointestinal stromal tumor is a rare pathology in childhood. It may occur anywhere along the alimentary tract and represents with a wide spectrum of signs and symptoms according to location. An infant with malignant colonic stromal tumor that has presented with a huge abdominal mass and lower gastrointestinal bleeding is reported to discuss the difficulties in diagnosis and differential diagnosis of this unusual tumor.

Epithelioid gastrointestinal stromal tumor of the stomach with liver metastases in a 12-year-old girl: aspiration cytology and molecular study

Gastrointestinal stromal tumor (GIST), a stromal tumor of the gastrointestinal tract defined as CD117 (c-kit)-positive neoplasm, occurs primarily in adults. GIST with CD117 (c-kit) mutation and certain cytogenetic abnormalities is associated with malignancy, though a definite relationship between prognosis and molecular alterations remains to be elucidated. We report the cytologic features of an epithelioid GIST arising in the stomach of a child and metastatic to the liver, and the molecular mutational analysis of both the primary gastric tumor and the liver metastasis. Literature of pediatric GISTs was also reviewed. Fine needle aspiration of the liver metastasis, processed by Ultrafast Papanicolaou stain, showed fragments of cohesive small epithelioid cells with bland oval nuclei and unipolar cytoplasm transected by capillaries. Immunohistochemically, all nodules in the stomach and liver expressed CD117 (c-kit). Interestingly, some of the gastric tumor clusters were uniformly CD34 positive, whereas others were uniformly CD34 negative, suggesting heterogeneity of tumor clones. The presence of neurosecretory granules further subtyped the tumor into gastric autonomic nerve tumor (GANT). Molecular mutational analysis, performed in both the gastric tumor and the liver metastasis, showed no sequence abnormality in exons 9, 11, and 13 of CD117 (c-kit). Cytogenetic study revealed normal karyotype. These features might suggest a different molecular mechanism leading to malignancy in certain GISTs arising in children.