Tumors of Early Childhood Flashcards
What is the most common death in children?
Accidents (40%) Cancer only accounts for 11%
What is the most common malignancy in children?
Leukemia
What is the biggest difference in type of tumors in the pediatric vs adult population?
Carcinoma (epithelial-derived tumors) are not uncommon in adults while they are VERY rare in children
What is a neuroblastoma?
Neuroendocrine tumor arising from any neural crest element of the sympathetic nervous system -2nd most common malignancy in childhood
What is the median age of diagnosis of a neuroblastoma?
22 months
What is the most common site of a neuroblastoma?
Adrenal glands
Two clinical presentations of a neuroblastoma
Often fever w/ (a) palpable abdominal mass- often of the adrenals (b) Elevated urine catecholamine metabolites 90% of neuroblastomas secrete catecholamines
Differentiate neuroblastomas from ganglioneuromas
Depends on the percentage of Schwannian development 50% Schwannian development = Ganglioneuroma
Describe the staging of neuroblastomas
Typical stages I-IV I- tumor confined to structure of origin III- LN IV- distant mets Special Stage IV-S = stage I or II tumor w/ remote disease in the liver, skin, or bon marrow -very good prognosis -must be
What is distinct about Stage IV-S
Stage 4-S is a distinct stage of neuroblastoma where the primary tumor is of stage I-II, but there is remote disease in the liver, skin, or bone marrow -very good prognosis despite distant mets -must be an infant (
Better prognosis for children over of under 1 year of age dx w/ neuroblastoma
Better prognosis for those
What gene is amplified in many cases of neuroblastoma?
N-myc -amplification of N-myc oncogene is a common finding in neuroblastoma and is associated w/ bad prognosis
What tumor contains pseudo-rosettes on histology?
25-30% of neuroblastomas show pseudo-rosettes
Describe the classic histological appearance of a neuroblastoma
Presence of neuropil (stromal background) within a small round blue cell tumor -neuropil = fine, fibrilliary, eosinophilic material
What is a Wilm’s tumor?
= Nephroblastoma -malignant neoplasm derived from nephrogenic blastema -most common renal tumor of childhood
Median age of diagnosis of Wilm’s tumors
3-4 yoa
What percent of Wilm’s tumors are syndromic? What gene is commonly mutated in syndromic Wilm’s tumors?
10% of Wilm’s tumors are syndromic, due to mutation in WT-1 gene -WAGR syndrome = deletion of WT1 -Denys-Drash syndrome = missense mutation in WT1 Beckwith-Wiedemann syndrome = WT2 disruption
Which childhood tumor do you not want to biopsy?
Wilm’s tumor -don’t want to biopsy b/c any rupture of the encapsulation puts the patient at risk of hemorrhage age peritoneal dissemination -so pre-surgical biopsy is rarely (if ever) indicated b/c it will result in automatic upstaging of the tumor
What is the most common presentation of a Wilm’s tumor?
Enlarged abdomen -usually due to mass
What is the most important histological feature for predicting prognosis and response to treatment of a Wilm’s tumor?
Absence or presence of anaplasia Anaplasia defined by mitotic figures and nuclear enlargement
Describe what it means to be a triphasic tumor?
Triphasic = comprises 3 elements, one from each of the categories (a) Blastema- cells that can grow/regenerate into organs or body parts (b) Mesenchyme- derivative of CT (c) Epithelium
What is an Ewing/PNET (Primitive neuroectodermal tumor)
Malignant (cancerous) neural crest tumor, cells aren’t fully developed into neurons => called primitive
Tumor that diffusely stains for CD-99 on immunohistochemistry
Ewing/PNET
What is the genetic etiology of Ewing/PNET?
Translocations- most common is the EWS/FLI-1 fusion gene -EWS-FLI-1 fusion gene due to reciprocal translocation. Transcription factor that upregulates FLI-1 expression
