Childhood intestinal tumors

Dr. Zahoor Ahmad

Pediatric GIST•Extremely rare tumors•Predilection for girls•multifocal location•Usually familial disease but sporadic cases have been reported.• lack oncogenic mutations in KIT/PDGFRA genes (present in adulthood).

all pediatric GISTs show consistent biochemical activation and overexpression by immunehistochemistry of the KIT receptor tyrosine kinase.

Morphologically the tumors have either a predominantly epithelioid or mixed epithelioid-spindle cell appearance.

In contrast with adult GIST, pediatric tumors tend to have a multinodular growth, with partial excisions being often followed by local recurrence at the stump.

Another important distinction from the adult counterpart is their indolent clinical behavior, even in the presence of loco-regional or distant metastatic disease.

•Imitinib is effective in GIST but surgery is preffered.•broad-based, kinase inhibitors, such as sunitinib, has been questioned as the first-line therapy in metastatic pediatric GIST

imatinib-alternative drugs, such as nilotinib, sorafenib and dasatinib are being tested for their efficacy in an in vitro murine Ba/F3 cell system expressing the wild-type

There is some role of radiotherapy in treatment of GIST.

Myofibromatosis

Infantile myofibromatosis is a mesenchymal tumor that can arise in the skin, muscle, bone, subcutaneous tissue, or viscera. It is the most common fibrous tumor of infancy.

Myofibromatosis presents with either solitary or generalized lesions, with or without visceral involvement. Most lesions spontaneously regress; however, extensive intestinal myofibromatosis is associated with significant morbidity and mortality.

Various chemotherapeutic interventions have demonstrated limited efficacy, significant treatment toxicity, and long-term morbidity. However, the combination of low-dose chemotherapy and long-term total parental nutrition for life-threatening infantile myofibromatosis can provide symptomatic relief and inhibit disease progression.

Carcinoid tumorsCarcinoid tumors originate from neuroendocrine cells within the GI tract. These neoplasms derive from GI epithelial and subepithelial endocrine progenitor cells that function as part of the amine precursor uptake and decarboxylation (APUD) system.

Pediatric carcinoid tumors typically occur in the GI tract—stomach, small intestine, appendix (most common), and rectum. Carcinoid tumors of the appendix occur with an estimated incidence of 1 case per million children per year, with a slight female predominance

Colorecta carcinomaAdenocarcinoma of the colon and rectum is the most common cancer of the GI tract. The lifetime risk of developing colorectal cancer in the general population is 1 in 19. However, colorectal cancer in children is rare, with an estimated incidence of 0.3 to 1.5 cases per million. Although reported as early as 9 months of age, the median age at diagnosis for pediatric cases is 15 to 19 months. Pediatric colorectal cancer accounts for 2% of malignancies in adolescents.

Inflammatory pseudotumors• Inflammatory myofibroblastic tumour, plasma cell granuloma, and inflammatory fibrosarcoma. • Inflammatory myofibroblastic tumours are characterized by a mix of inflammatory cells, e.g. plasma cells, lymphocytes and eosinophils, and spindle cells without nuclear atypia. These tumours may have necrosis, hemorrhage, focal calcification and mitotic activity.

LeiomyomaLeiomyoma (plural leiomyomas or leiomyomata) (leio- + myo- + -oma, "smooth-muscle tumor") is a benign smooth muscle neoplasm that is very rarely (0.1%) premalignant. They can occur in any organ, but the most common forms occur in the small bowel and the esophagus.

LymphomaGastrointestinal tract is the most common extranodal site involved by lymphoma with the majority being non-Hodgkin type. Although lymphoma can involve any part of the gastrointestinal tract, the most frequent sites in order of its occurrence are the stomach followed by small intestine and ileocecal region.

Gastrointestinal tract lymphoma is usually secondary to the widespread nodal diseases and primary gastrointestinal tract lymphoma is relatively rare. Gastrointestinal lymphomas are usually not clinically specific and indistinguishable from other benign and malignant conditions

Diffuse large B-cell lymphoma is the most common pathological type of gastrointestinal lymphoma in essentially all sites of the gastrointestinal tract, although recently the frequency of other forms has also increased in certain regions of the world.

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