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47 Cards in this Set
- Front
- Back
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What is the most common extracranial solid tumor in children? What percent of all childhood tumors does
this comprise? What are the most common ages of pediatric patients with neuroblastoma? What is the most median age at diagnosis? |
Neuroblastoma, 8-10% of all childhood cancers
◦ 50% occur in children younger than 2 years old ◦ 75% are diagnosed by age 4 ◦ The median age at diagnosis is 21 months |
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From which cells does neuroblastoma arise? Explain the concept of “in situ” neuroblastoma
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◦ From neural crest cells that form the adrenal medulla and sympathetic ganglia
◦ May occur anywhere along sympathetic chain within neck, thorax, retroperitoneum, pelvis or adrenal gland (75% in retroperitoneum: 50% adrenal and 25% paravertebral ganglia) ◦ Small nodules of neuroblasts found incidentally in the adrenal gland (indistinguishable from neuroblastoma). Studies have shown that these are present in all fetuses and spontaneously regress. Neuroblastoma on prenatal ultrasound therefore offers a favorable prognosis. |
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What are the important prognostic factors with respect to neuroblastoma?
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Clinical Variables:
1. Age: Children diagnosed <1yo have better prognosis 2. Site: Nonadrenal primary tumors with better prognosis 3. Stage: Stages 1, 2, and 4S have better prognosis ◦ Biologic Variables: 1. Deletion of short arm chrom. 1 (70-80% of cases) (bad prognosis) 2. Aneuploidy of tumor DNA (good prognosis) 3. Amplification of N-myc oncogene (bad prognosis) |
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Describe the histopathologic classification scheme of neuroblastoma. Does this aid in predicting
prognosis? |
◦ Shimada classification
1. Stroma Poor (poor prognosis in general) 1. Favorable (young age of diagnosis) 2. Unfavorable (older age at diagnosis) 2. Stroma Rich (favorable prognosis) 1. Nodular (least favorable of this group) 2. Intermixed 3. Well-differentiated |
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Describe the clinical findings in neuroblastoma. What percent of patients diagnosed with neuroblastoma
have metastases at the time of diagnosis? |
◦ The majority will have abdominal pain or palpable mass
◦ Many will have manifestations of metastasis (e.g. bone/joint pain, periorbital ecchymosis, cough/dyspnea, neurologic deficits from cord compression) ◦ 70% of patients will have metastases at diagnosis |
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Describe 3 paraneoplastic syndromes associated with neuroblastoma.
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◦ Catecholamine release similar to pheochromocytoma à paroxysmal HTN, palpitations, flushing,
headache ◦ Vasoactive intestinal peptide (VIP) release à watery diarrhea and hypokalemia ◦ Acute myoclonic encephalopathy à myoclonuse, opsoclonus, ataxia |
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What laboratory studies are ordered in diagnosing neuroblastoma?
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◦ Urinary catecholamine metabolites (VMA and HVA) found in 90-95%; can monitor for
decrease w/treatment ◦ CBC (to assess for anemia from bone marrow involvement) followed by bone marrow biopsy |
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What imaging studies are important when diagnosing neuroblastoma?
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◦ Plain films may demonstrate a calcified abdominal or posterior mediastinal mass
◦ Bone scintigraphy and skeletal survey to look for cortical bone metastases ◦ MIBG scintigraphy to determine extent of disease and recurrence (unclear impact on treatment) ◦ U/S, CT, or MRI to offer information about local extent of tumor |
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Japan has been screening for neuroblastoma for over 20 years and their studies show uniformly favorable
survival (>97%) in these patients. Is this evidence that we should screen our kids? |
◦ No- two prospective trials have shown no benefit (no improvement in survival). Those
diagnosed with urine screening already have a favorable prognosis and many spontaneously resolve without therapy. |
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How would you go about diagnosing pheochromocytoma in a child?
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◦ Plasma metanephrine levels
◦ CT or T2-weighted MRI will detect most lesions ◦ If extra-adrenal location, MIBG is very sensitive |
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What percent of RMS arises from the GU system? What are the most common organs affected? What is
the age of diagnosis of RMS? |
◦ 15-20% arise from GU system.
◦ Most commonly affected are the prostate, bladder, and paratesticular region ◦ Bimodal distribution (peak in first 2 years of life, and again at adolescence), 2/3 present in less than 6 years old |
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What are the three major histologic subtypes of RMS? Which Embryonal sub-type variants are associated
with excellent survival? Where does metastatic RMS usually spread? What is the best predictor of outcome for RMS? |
◦ Embryonal (most common), alveolar, and pleomorphic
◦ Sarcoma botryoides and spindle cell ◦ To the lungs ◦ Tumor stage at diagnosis |
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What familial syndrome is associated with RMS? What mutation is most commonly found?
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◦ Li-Fraumeni syndrome (association of sarcomas with mothers who have excess premenopausal
breast cancer and siblings with increased risk of cancer) ◦ p53 tumor suppressor gene mutation found in all patients |
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How does bladder and prostate RMS differ in location and gross appearance? What is the focus of
treatment of bladder and prostate RMS? How do you treat? |
◦ Bladder: intraluminal mass, usually botryoid at or near trigone; Prostate: solid mass
◦ Focus of treatment is preserving an intact bladder ◦ Treat with chemo/radiation before surgical resection and then partial cystectomy |
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How do paratesticular RMS present? What percentage of RMS is in this location? Where does it arise?
What kind of workup should be performed when diagnosing paratesticular RMS? What is current survival rate w/proper treatment of paratesticular RMS? |
◦ 7-10% of RMS arise in the paratesticular area and presents with unilateral painless scrotal
swelling or mass distinct from testis ◦ Arises from distal spermatic cord, may invade testis & surrounding structures ◦ CT abdomen/pelvis to evaluate retroperitoneal mets (occurs in 20%), although there is 14% false-negative rate ◦ With proper treatment, the current survival rate is 90% |
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What is the initial surgical treatment of paratesticular RMS? What kind of incision would you make and
why? What if a trans-scrotal procedure was performed? |
◦ Radical inguinal orchiectomy because if removed through a scrotal procedure, the risk for local
recurrence and non-regional LN spread is increased. ◦ If a trans-scrotal procedure was performed, you should go back and perform an inguinal exploration, removing the remaining spermatic cord and a partial hemiscrotectomy which includes the previous scrotal incision. |
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T/F: Wilms’ tumor is the most common extracranial solid tumor of childhood.
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◦ False, it is the most common primary malignant renal tumor of childhood
◦ Accounts for 6-7% of all childhood cancers, incidence 7-10 cases/million ◦ Neuroblastoma is the most common extracranial tumor of childhhod |
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What is the typical age for Wilms’ Tumor? What percentage have a family history of Wilms’ tumor?
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◦ Greater than 80% occur in patients less than 5 years old; median age is 3.5 years old
◦ Occurs earlier in male patients and those with bilateral disease ◦ 1-2% have a family history of Wilms’ tumor |
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What syndromes are associated with increased incidence of Wilms’ Tumor and how common are they?
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◦ GU anomalies (hypospadias and/or cryptorchidism)- in 4.5% of Wilms’ cases
◦ Denys-Drash syndrome (male pseudohermaphroditism, renal mesangial sclerosis, and nephroblastoma) ◦ Aniridia- found in 1.1% of Wilms’ cases- especially in WAGR syndrome (Wilms’, Aniridia, Genital anomalies, mental Retardation) ◦ Horseshoe kidney: 7-fold increased risk of Wilms’ ◦ Beckwith-Wiedemann syndrome: excess growth at cellular, organ (macroglossia, nephro/ hepatomegaly) or body segment (hemihypertrophy) levels, confers 4-10% risk of nephroblastoma with 20% bilateral |
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Which children should be screened for Wilms’ tumor, and how/when should this be done?
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◦ Those with aniridia, hemihypertrophy, and BWS (screen with serial renal ultrasound at 3-4
month intervals) |
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What are the two genes that have been associated with Wilms’ tumor and on what chromosomes are they
located? What associations do they have? |
◦ WT1 (chromosome 11p13): associated with WAGR (inactivated WT1 protein) & Denys-
Drash syndrome (dysfunctional WT1 protein) ◦ WT2 (chromosome 11p15): associated with BWS |
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Describe the histopathology of Wilms’ tumor and why this affects prognosis.
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◦ “Classic” Wilms’ is Triphasic: islands of compact, undifferentiated blastemal cells, variable
epithelial cells and stromal cells ◦ Predominant blastemal pathology is highly aggressive whereas epithelial predominant is least aggressive |
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What patients are more commonly associated with anaplastic histology of Wilms’?
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◦ Patients older than 5 year old
◦ Associated with resistance to chemo (which is source of aggressiveness) |
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If a patient is known to have nephrogenic rests as well as Wilms’, what do you worry about?
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◦ Contralateral disease- so annual surveillance is necessary
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What are the common presenting symptoms associated with Wilms’ tumor?
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◦ Palpable smooth abdominal mass
◦ Abdominal pain, gross hematuria, fever ◦ Acute abdomen (if tumor ruptures) ◦ HTN (in 25% of cases) |
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What imaging modality provides a definitive diagnosis of Wilms’ tumor? What diagnostic study should be
performed first in suspected Wilms’ tumor? |
◦ None. All solid renal tumors of childhood have the same radiographic appearance.
◦ Renal ultrasound (to determine solid nature of lesion) and doppler to exclude intracaval extension (occurring in 4% of patients) |
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What are the pitfalls of CT/MRI in staging Wilms’ tumor? What is the purpose of thin slice CT/MRI in
the setting of Wilms’ tumor? |
◦ Regional adenopathy may indicate nodal involvement or normal benign enlargement common in
children; detection of extension into perirenal fat and adjacent structures is difficult to analyze because it is usually the result of compression, not frank invasion ◦ Thin slice imaging can define extent of lesion including nodal involvement, can assess the contralateral kidney for evidence of Wilms’, can rule out pulmonary metastasis (most common site; if these are present, one would consider chemotherapy before surgery) |
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What is the initial therapy for most Wilms’ tumor?
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◦ Radical nephrectomy via transperitoneal approach. It is up to the SURGEON to determine tumor
extent. |
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What are the 3 main indications for preoperative chemotherapy versus immediate nephrectomy?
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◦ Bilateral tumors
◦ Inoperative tumors at time of surgical exploration ◦ Tumor extension into vena cava above hepatic veins |
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What is the treatment protocol for bilateral Wilms’ tumors?
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◦ Biopsy first
◦ Preoperative chemotherapy x 4-6 weeks ◦ Re-exploration with partial nephrectomies |
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What percent of primary testicular tumors in prepubertal children are benign?
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◦ 74%
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True/False: Patients with intersex disorders have an increased incidence of gonadal tumors.
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◦ True. These include androgen insensitivity syndrome and gonadal dysgenesis (the latter with a
risk that is increased in the presence of a Y chromosome- 10% incidence of tumor development by 20yo) |
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What is the characteristic histopathology associated with yolk sac tumor?
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◦ Schiller-Duval bodies
◦ AFP present via staining ◦ Mixture of epithelial and mesenchymal cells in organoid pattern |
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What is the pathognomonic histologic feature of Leydig cell tumor?
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◦ Reinke’s crystals (present in only 40% of these tumors)
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Is there an association between cryptorchidism and development of CIS?
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Yes- CIS incidence is 1.7% in adults who previously underwent orchiopexy
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What sonographic features distinguish benign and malignant testicular tumors in children?
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◦ None really but anechoic cystic lesions can suggest a benign lesion.
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What are the unique sonographic findings of an epidermoid cyst?
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Heterogenous intratesticular mass with concentric rings of alternating hypoechoic and
hyperechoic layers (“onion skin” appearance) |
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What lab test may help identify tumors amenable to testis-sparing procedure?
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◦ AFP (YSTs always produce AFP and all AFP+ tumors have yolk sac components
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When do AFP levels reach adult levels? What is the ½ life of AFP? Of beta-HCG?
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◦ At 8 months of age. Until then, AFP levels may be normally elevated in infant boys and do not
necessarily indicate malignant disease ◦ 5 days ◦ 24 hours |
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What is the most common prepubertal testis tumor in children? How does this differ from adults?
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◦ Teratoma, immature has much more benign course than those in adults
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How are testicular teratomas managed?
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◦ Testis-sparing procedure via inguinal incision (no radical orchiectomy)
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What is the initial treatment for YST? What is the most common site of distant metastasis in YSTs?
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◦ Radical inguinal orchiectomy (routine RPLND and chemo NOT indicated)
◦ Follow with chest xray/CT/MRI monthly x 3 months, q3mos, then q6mo for 36 months ◦ Lung and retroperiteonal LN |
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What is the most common sex cord tumor and what is the peak age incidence?
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◦ Leydig cell tumor (4-5 yo)
◦ Sertoli cell tumors occur earlier in age |
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What substances are produced by Leydig cell tumors?
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◦ Testosterone (causing precocious puberty), corticosteroids, progesterone, estrogens
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What is the differential diagnosis of precocious puberty?
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◦ Leydig cell tumors
◦ Pituitary lesions ◦ Large cell Sertoli cell tumors ◦ Hyperplastic testicular nodules from CAH |
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What is the treatment for Leydig cell and Sertoli cell tumors?
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◦ Inguinal orchiectomy although testis-sparing surgery now reported
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Children with mixed gonadal dysgenesis have what % risk for Gonadoblastoma formation?
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◦ 25% (and incidence increases with age)
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