Malignant Tumors of the Gastrointestinal Tract, Liver, and Endocrine System



Malignant Tumors of the Gastrointestinal Tract, Liver, and Endocrine System


Victor A. Lewis

Douglas R. Strother



Whereas metastases from pediatric tumors to sites within gastrointestinal (GI) tract are relatively common, primary GI neoplasms are exceedingly rare in children. Because of this rarity, their treatment has been adapted from that of adults with similar tumors.


HEPATIC NEOPLASMS

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common hepatic malignant diseases. Much less commonly, undifferentiated sarcoma of the liver (known also as embryonal sarcoma or malignant mesenchymoma of the liver), hemangiosarcoma, and cholangiocarcinoma may occur. Rhabdomyosarcoma and undifferentiated sarcomas arising from the biliary tract are discussed elsewhere.

HB and HCC occur as a right upper quadrant mass. Both diseases are associated with a male preponderance, whereas HB clearly occurs in younger children, with a median age of 16 months at diagnosis. Associations with overgrowth syndromes, such as the Beckwith-Wiedemann syndrome, and with hemihypertrophy and isosexual precocity have been described with HB. Patients may present with thrombocytosis and anemia. Although osteopenia occurs commonly with HB, it is not indicative of metastatic disease. Alpha-Fetoprotein is a tumor marker for HB that is usually elevated at diagnosis. Patients with HCC generally are older, with a median age of onset of 12 years, and they appear more ill at diagnosis. They commonly present with nausea, vomiting, fever, and abdominal pain. Multifocal liver involvement with metastasis to extrahepatic sites is common at diagnosis. HCC is associated with hepatitis B, but cirrhosis may or may not be present.

Ultrasound examination of the abdomen is useful in identifying both types of hepatic tumors. Computed tomography, or, for better detail, magnetic resonance imaging, is necessary to define the intrahepatic extent of disease; both are useful for surgical management of disease. Computed tomography and nuclear medicine imaging are used to identify extrahepatic metastases.

Although complete removal of primary HB and HCC is necessary for cure, this can be accomplished in only in one-half of HB and one-third of HCC cases. Neoadjuvant chemotherapy can help to decrease the size of HB to allow later complete excision. Postsurgical chemotherapy is not required after complete excision of HB with purely fetal histology. In cases of embryonal, anaplastic, and macrotrabecular HB, postsurgical chemotherapy reduces the risk of recurrence. Cisplatin, vincristine, doxorubicin, and 5-fluorouracil are among the most active drugs for HB.

Metastatic disease at time of diagnosis diminishes ultimate survival rates. Repeat operations are warranted for children with advanced or recurrent disease. If surgical excision of the primary tumor is achieved, metastatic disease can be controlled with chemotherapy. Surgical control of metastatic disease has also contributed to long-term survival.

Although HCC is sensitive to chemotherapy, responses are less durable than in patients with HB. Platinum compounds, cyclophosphamide, doxorubicin, etoposide, and 5-fluorouracil have shown activity against HCC. Chances of survival are increased with adjuvant chemotherapy after complete resection
of HCC. Residual or metastatic disease carries an extremely poor prognosis. Radiation therapy only helps to control microscopic residual disease.

The role of stem cell rescue after high-dose chemotherapy is controversial, and newer drugs, such as irinotecan, are being tested actively in recurrent and high-risk cases.


OTHER TUMORS OF THE GASTROINTESTINAL TRACT


Oropharyngeal Tumors

Carcinoma of the oropharynx has been observed in older children. These tumors are primarily mucoepidermoid carcinomas involving the salivary glands. Rare cases of squamous cell carcinoma of the lip or tongue in childhood also have been reported. Esophageal carcinoma has been found in patients as young as 15 years.


Gastric Tumors

Malignant gastric tumors in children are usually lymphomas or sarcomas, but gastric adenocarcinomas have been documented. Most primary tumors found in the stomach are benign, and surgical resection is curative. For malignant gastric disease, surgery is the initial therapy, with postoperative radiation therapy or chemotherapy as indicated.

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Jul 24, 2016 | Posted by in ORTHOPEDIC | Comments Off on Malignant Tumors of the Gastrointestinal Tract, Liver, and Endocrine System
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