Ch 10 Tumors and Tumor-Like Lesions of Infancy and Childhood

Question 1

neruoblastoma

Answer 1

most common extracranial solid tumor o childhood and most frequently diagnosed tumor of infancy

Question 2

neruoblastoma - morphology

Answer 2

40% arise in the adrenal medulla
insitu lesions can regress leaving only fibrosis or calcification
soft gray tan tissue w/ areas of necrosis

Question 3

neuroblastoma - clinical courses

Answer 3

young - large abdominal masses, fever, weight loss
older - bone pain, respiratory symptoms, GI
multiple cutaneous metastases that cause deep blue discoloration of the skin

Question 4

neuroblastoma - prognostic factors

Answer 4

age and stage are the most important determinants of outcome
age of 18 mo
amplification of MYCN

Question 5

WAGR syndrome

Answer 5

characterized by Wilms tumor, aniridia, genital anomalies, and mental retardation
Constitutional deletion of 11p13
WT1 and PAX6 - loss of PAX6 will not lead to Wilms Tumor
1st hit is the germline deletion
2nd hit is frameshift mutation

Question 6

Denys-Drash syndrome

Answer 6

Characterized by gonadal dysgenesis (male pseudohermaphroditism) and early-onset nephropathy leading to renal failure
Characteristic glomerular lesion in these patients is a diffuse mesangial sclerosis
Dominant negative missense mutation in zinc finger region of WT1 can only lead to GU abnormalities
Must have biallelic inactivation of WT1
Increased risk of gonadoblastoma
WT1 protein is critical for normal renal and gonadal development

Question 7

beckwith-weidemann syndrome

Answer 7

characterized by enlargement of body organs (organomegaly), macroglossia, hemihypertrophy, omphalocele, and abnormal large cells in the adrenal cortex (adrenal cytomegaly)
11p15.5 (WT2)
IGF-2 is normally expressed solely from the paternal allele
Loss of imprinting can lead to overexpression of IGF-2 protein
Embryonal growth factor
CDKN1C (p57) - cell cycle regulator
At lower risk for developing tumor
BWS are also at increased risk for developing hepatoblastoma, pancreatoblastoma, adrenocortical tumors, and rhabdomyosarcomas

Question 8

morphology - wilms tumor

Answer 8

The classic triphasic combination of blastemal, stromal, and epithelial cell types is observed in the vast majority of lesions

Question 9

clinical features - wilms tumor

Answer 9

Present with a large abdominal mass that may be unilateral or, when very large, may extend across the midline and down into the pelvis
Pulmonary metastases are present at the time of primary diagnosis
Increased survival has lead to increased risk of developing second primary tumors
bone and soft-tissue sarcomas, leukemia and lymphomas, and breast cancers
Treated by radiation