Pediatric neoplasms

TABLE 17.1 Key Pathologic, Immunohistochemical, and Genetic Features of Selected Pediatric Neoplasms ... 

Different neoplasms of brain predominate in adults and in children. More pediatric neoplasms occur in the posterior fossa than in the anterior fossa, and the opposite is true of adult neoplasms. 

Patients with preexisting tumors or growth hormone deficiency secondary to an intracranial lesion should be examined routinely for progression or recurrence of the underlying disease process. In pediatric patients, clinical literature has revealed no relationship between somatropin replacement therapy and central nervous system (CNS) turmor recurrence or new extrracranial tumors. However, in childhood cancer survivors, an increased risk of a second neoplasm has been reported in patients treated with somatropin after their first neoplasm. Intracranial tumors, in particular meningiomas, in patients treated with radiation to the head for their first neoplasm, were the most common of these second neoplasms. In adults, it is unknown whether there is any relationship between somatropin replacement therapy and CNS tumor recurrence... 

Metabolic bone disease in children receiving parenteral nutrition manifests primarily as osteopenia and, on occasion, fractures (5). The etiology is multifactorial calcium and phosphate deficiency play a major role in the preterm infant but the part played by aluminium toxicity in this population is unknown. Lack of reference values of bone histomorphometry in the premature infant, as well as lack of reference data for biochemical markers of bone turnover in these patients, contributes to the uncertainty. Other factors that may play a role in the pathogenesis of bone disease associated with parenteral nutrition include lack of periodic enteral feeding underljdng intestinal disease, including malabsorption and inflammation the presence of neoplasms and drug-induced alterations in calcium and bone metabohsm. However, the true incidence and prevalence of parenteral nutrition-associated bone abnormalities in pediatric patients are unknown. 

Hematopoietic neoplasms only rarely present as soft tissue masses, and this phenomenon is particularly unusual in pediatric patients in whom other forms of small round cell tumors are most common. Because of the virtually ubiquitous presence of CD45 in hematopoietic cells and its extremely high degree of specificity, that marker is very valuable in this context. Not all antibodies raised against CD45 identify determinants that survive routine tissue processing, but the monoclonal antibody cocktail PD7/26 2B11 (see Table 4.3) is indeed active in paraffin sections. 

Vedrine PO, Coffinet L, Temam S, et al. Mucoepidermoid carcinoma of salivary glands in the pediatric age group 18 clinical cases, including 11 second malignant neoplasms. Head Neck. 2006 28(9) 827-833. 

Argani P, Hawkins A, Griffin CA, et al. A distinctive pediatric renal neoplasm characterized by epithelioid morphology, basement membrane production, focal HMB45 immunoreactiv-ity, and t(6 ll)(p21.1 ql2) chromosome translocation. Am J Pathol. 2001 158(6) 2089-2096. 

Many different antibodies are used for the immunohistochemical evaluation of pediatric solid neoplasms. The more generally used antibodies are discussed in other... 

WT, or nephroblastoma, is the most common pediatric renal neoplasm. Ninety-eight percent occur before 10 years of age, and there is no sex predilection. It is derived from nephrogenic blastemal cells and thus can exhibit a wide range of histologic appearances that replicate the developing kidney and display divergent differentiation. Most WT are unicentric, but 7% are multicentric and 5%... 

Judkins AR, Mauger J, Ht A, et al. Immunohistochemical analysis of hSNF5/INIl in pediatric GNS neoplasms. Am J Surg Pathol. 2004 28 644-650. 

The common non-epithelial neoplasms that cause malignant effusions include malignant melanomas, lymphomas, sarcomas, germ cell tumors, and some pediatric malignant tumors. The determination of origin of non-epithelial malignancies on purely cytomorphologic... 

Germ cell neoplasms are common in pediatric patients as well as young adults. Seminomas are occasionally found in malignant effusions in pleura, peritoneum, and hydrocele sac." Dysgerminoma is the female counterpart of the seminoma and rarely presents in effusions. These tumors can occur as pure tumors or as mixed tumors with other germ cell tumors, and they have potential to metastasize. Cell blocks have been proven to be a useful tool in the immunohistochemical studies performed to diagnose and differentiate components of mixed germ cell tumors. 

It is, however, pertinent to mention here that the active form of the drug is its respective metabolite, prednisolone. Prednisone remarkably exhibits 3 to 5 folds the glucocorticoid activity in comparison to hydrocortisone, whereas it distinctly shows somewhat reduced mineralocorticoid activity nevertheless, it may cause noticeable sodium retention and potassium depletion. It enjoys the reputation of being the glucocorticoid of choice for use in cancer chemo-therapy both profusely and predominantly, but preferentially along with other drugs. It also finds its abundant usage in pediatrics for the treatment of nephrosis, rheumatic carditis, neoplasms, leukemias, and tuberculosis. 

Undifferentiated embryonal sarcoma (UES) is a rare and highly malignant hepatic neoplasm, affecting almost exclusively the pediatric population. A total of 63% of patients are between 6-10 years of age, and it commonly occurs in the first two decades of life. It has a survival rate of 40% at 3 years (O Sullivan et al. 2001 Lack et al. 1991). 

Helmberger TK (1999) Pediatric liver neoplasms a radiologic - pathologic correlation. Eur Radiol 9 1339-1347 Hinds R, Davenport M, Mieli-Vergani G et al (2004) Antenatal presentation of biliary atresia. J Pediatr 144 43-46 Hirohashi S, Hirohashi R, Uchida H et al (1997) Pancreatitis evaluation with MR cholangiopancreatography in children. Radiology 203 411-415... 

Fitch S, Parvey LS, Wiliams J et al (1985) Developmental cystic renal neoplasms in children Diagnostic imaging characteristics. Comput Radiol 9 149-158 Fredericks BJ, de-Campo M, Chow CW et al (1989) Glomerulocystic renal disease ultrasound appearances. Pediatr Radiol 19 184-186... 

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