General & Alternative Medicine Blog

Featured Articles

Tumors And Tumor Like Lesions Of Infancy And Childhood

10:53 am by Admin in Cancer

Only 2% of all malignant tumors occur in infancy and childhood; nonetheless, cancer (including leukemia) is the leading cause of death from disease in the United States in children over the age of 4 and up to 14 years of age. Neoplastic disease accounts for approximately 9% of all deaths in this cohort; only accidents cause significantly more deaths. Benign tumors are even more common than cancers. Most benign tumors are of little concern, but on occasion they cause serious disease by virtue of their location or rapid increase in size. It is sometimes difficult to segregate, on morphologic grounds, true tumors or tissues that are present in abnormal locations. Examples of heterotopias include a rest of pancreatic tissue found in the wall of the stomach or small intestine or a small mass of adrenal cells found in the kidney, lungs, ovaries, or elsewhere. The heterotopic rests are usually of little significance, but they can be confused clinically with neoplasms. Rarely, they are sites of origin of true neoplasms, producing the paradox of an adrenal carcinoma arising in the overy.

The term hamartoma refers to an excessive but focal overgrowth of cells and tissues native to the organ in which it occurs. Although the cellular elements are mature and identical to those found in the remainder of the organ they do not reproduce the normal architecture of the surrounding tissue. Hamartomas can be thought of as the linkage between malformations and neoplasms the line of demarcation between a hamartoma and a benign neoplasm is frequently tenous and is variously interpreted. Hemangiomas; lymphagiomas; rhabdomyomas of the heart; adenomas of the liver; and developmental cysts with the kidneys, lungs, or pancreas are interpreted by some as hamartomas and by others as true neoplasms. The frequency of these lesions in infancy and childhood and their clinical behaviour give credence to the belief that many are developmental aberrations. Their unequivocally benign histology, however, does not preclude bothersome and rarely life-threatening clinical problems in some cases.

Benign tumors and tumor-like lesions

Reference has already been made to the difficulty in distinguishing benign tumors from hamartomas. Benign neoplasms are far more common in infancy and childhood than are cancers. Virtually any tumor may be encountered but within this wide array hemangiomas, lymphangiomas, fibrous lesions, and teratomas deserve special mention.

Hemangiomas

Hemangiomas are the most common tumors of infancy. Architecturally, they do not differ from those encountered in elder age. In children most are located in the skin, particularly on the face and scalp, where they produce flat-to-elevated, irregular, redblue masses; some of the flat, larger lesions(considered by some to represent vascular ectasias) are referred to as port-wine stains. Hemangiomas may enlarge along with the growth of the child, but in many instances they spontaneously regress. In addition to their cosmetic significance, they can represent one facet of the hereditarydisorder, von Hippel-Lindau disease. Rarely, vascular tumors, particularly those in the liver and soft tissues, become malignant.

Lympatic tumors

A wide variety of lesions are of lympatic origin. Some of them- lymphangiomas are hamartomatous or neoplastic in origin whereas other appear to represent abnormal dilations of preexisting lymph channels known as lymphangiectasis. The lymphangiomas are usually characterized by cystic and cavernous spaces. Lesions of this nature may occur on the skin but, more important are encountered in the deeper regions of the neck, axilla, mediastinum, tetroperitoneal tissue, and elsewhere. Although histologically benign they tend to increase in size after birt, both by the collection of fluid and by the budding of preexisting spaces. In this manner, they may encroach on vital structures, such as those in the mediastinum or nerve trunks in the axilla, to constitute clinical problems. Lymphangiectasis, in contrast , usually presents as a diffuse swelling of part or all of an extremity; considerable distortion and deformation may result as a consequence of the spongy, dilated subcutaneous and deeper lymphatics. The lesion is not progressive, however, and does not extend its original location. Nonetheless, it give rise to difficult corrective cosmetic problems.

Fibrous tumors

Fibrous tumors occuring in infants and children range from sparsely cellular proliferations of spindle-shaped cells (designated as fibromatosis) to richly cellular lesions indistinguishable from fibrosacomas occuring in elders. Biologic behavior cannot be predicted based on histology alone, however, because some of the lesions (including the cellular fibromatoses or infintile fibrosarcomas) may spontaneously regress. In some of these soft tissue fibrous lesions, a variable proportion of the cells acquire a moderate amount of pink cytoplasm and express muscle specific action. These myofibromatoses present in infants and younger children and although usually solitay they may be multifocal involving any organ. Solitary lesions are benign, but multifocal lesions may result in significant morbidity and mortality when they involve vital organs.

Teratomas

Teratomas illustrate the relationship of histologic maturity to biologic behavior. They may occur as benign, well-differentiated cystic lesions or as solid malignant (immature) teratomas. They exhibit two peaks in incidence: the first at approximately 2 years of age and the second in late adolescence or growing stage. Sacrococcygeal teratomas occur in 1 in 20,000 to 40,000 live births, four times more frequently in girls than in boys. Occasionally diagnosed by prenatal imaging studies, these tumors may be associated with nonimmune hydrops fetails or polyhydraminos and depending on their size, may necessiate cesarean section delivery. In view of the overlap in the mechanisms underlying teratogenesis and oncogenesis it is interesting that approximately 10% of sacrococcgeal teratomas are associated with congenital anomalies, primarily defects of the hindgut and cloacal region and other midline defects (meningocele, spina bifida) not believed to be due to the local effects of the tumor. Approximately 75% of these tumors are histologically mature with a benign course and about 12% are unmistakably malignant ( containing endodermal sinus tumor) and lethal. The remainder are designated as immature teratomas, and their malignant potential correlates with the amount of immature tissue elements present. Most of the benign teratomas are encountered in younger infants

For more information about disease and treatment visit www.medicalhealthcenter.net

No Comments »

No comments yet.

RSS feed for comments on this post. TrackBack URL

Leave a comment