CHILDHOOD Flashcards
What is the most common primary childhood malignant renal tumor?
Wilm’s tumor (nephroblastoma)
What is the second most common malignant abdominal tumor in childhood?
Wilm’s tumor
What percentage of childhood malignancies does Wilm’s tumor comprise in the Philippines?
4.5% among 1–14 yrs old
What are the common sites of metastasis for Wilm’s tumor?
Lungs , regional lymph nodes, liver
What are the tumor suppressor genes involved in Wilm’s tumor?
WT1 & WT2 on chromosome 11p
What is the inheritance pattern of WT1 mutation in Wilm’s tumor?
Autosomal dominant
What percentage of Wilm’s tumors involve homozygous WT1 mutation?
10–15%
What is the most common clinical presentation of Wilm’s tumor?
Abdominal mass (60%)
What percentage of Wilm’s tumor cases present with abdominal pain?
40%
What percentage of Wilm’s tumor cases present with hypertension?
25%
What percentage of Wilm’s tumor cases present with gross painless hematuria?
15%
What imaging modality can help delineate an abdominal mass in Wilm’s tumor?
Abdominal x-ray
What are definitive imaging techniques for Wilm’s tumor diagnosis?
Renal ultrasound , CT scan, MRI
What lab findings may be seen in Wilm’s tumor?
Polycythemia or anemia , hematuria, pyuria, altered kidney/liver function tests
What are the treatment modalities for Wilm’s tumor?
Surgical resection , chemotherapy, radiotherapy
What is Stage I Wilm’s tumor?
Tumor confined to the kidney and completely resected
What is Stage II Wilm’s tumor?
Tumor extends beyond kidney but completely resected with negative margins
What is Stage III Wilm’s tumor?
Residual tumor after surgery confined to abdomen or tumor spillage
What is Stage IV Wilm’s tumor?
Hematogenous or distant lymph node metastases
What is Stage V Wilm’s tumor?
Bilateral renal involvement
What is the 3rd most common childhood malignancy?
Neuroblastoma
Where does neuroblastoma originate from?
Neural crest cells of the adrenal medulla and sympathetic nervous system
What proto-oncogene is amplified in aggressive neuroblastoma?
MYCN on chromosome 2
What is the median age at diagnosis for neuroblastoma?
17 months
What is the most common presenting symptom of neuroblastoma?
Abdominal mass and symptoms
What are signs of orbital metastases in neuroblastoma?
Periorbital ecchymosis (raccoon eyes)
What paraneoplastic syndromes are associated with neuroblastoma?
Secretory diarrhea , sweating, opsomyoclonus
What sites are common for neuroblastoma metastasis?
Liver , bone, bone marrow, lymph nodes
What is unique about Stage MS neuroblastoma?
Occurs in infants <18 months , metastases to skin, liver, or bone marrow with favorable prognosis
What histologic finding is characteristic of neuroblastoma?
Homer-Wright pseudorosettes
What percentage of neuroblastomas produce catecholamines?
About 90%
What are used to detect catecholamines in neuroblastoma?
Vanillylmandelic acid (VMA) and homovanillic acid (HVA) in urine
What is required for definitive diagnosis of neuroblastoma?
Tissue biopsy and genetic testing
What treatments are used for neuroblastoma?
Surgery , chemotherapy, radiotherapy
What is the most common intraocular childhood malignancy?
Retinoblastoma
What gene is mutated in hereditary retinoblastoma?
RB1 gene on chromosome 13q14
What is the difference between hereditary and sporadic retinoblastoma?
Hereditary is bilateral/multifocal , sporadic is unilateral/unifocal
What is the characteristic histologic finding in retinoblastoma?
Flexner-Wintersteiner rosettes
What is the most common clinical sign of retinoblastoma?
Leukocoria (white pupillary reflex)
What are other clinical signs of retinoblastoma?
Strabismus , decreased vision, hyphema, pupillary irregularity
What is the primary goal of retinoblastoma treatment?
Cure
What is the secondary goal of retinoblastoma treatment?
Preserve vision and decrease risk of late side effects
What are treatment options for retinoblastoma?
Cryotherapy , laser photoablation, enucleation, chemotherapy, radiation
What are histiocytosis syndromes characterized by?
Proliferation or accumulation of monocyte-macrophage system cells of bone marrow origin
What are histiocytes?
A form of white blood cell
What is the most well-known childhood histiocytosis?
Langerhans Cell Histiocytosis (LCH)
What is the hallmark of Langerhans Cell Histiocytosis?
Clonal proliferation of monocyte lineage cells containing Birbeck granules
What are Birbeck granules?
Tennis-racket shaped bilamellar granules diagnostic of LCH
What cells are CD1a-positive and CD207-positive with Birbeck granules?
Langerhans cells
Which disease is also called Histiocytosis X?
Langerhans Cell Histiocytosis
What are the three clinical entities under Histiocytosis X?
Hand-Schuller-Christian disease. Letterer-Siwe disease. Eosinophilic granuloma
Where are Langerhans cells located in the skin?
All layers of epidermis except the stratum corneum
What percentage of LCH cases have skeletal involvement?
LCH 80%
What bone sites are most often affected in LCH?
Skull. pelvis. femur. maxilla. mandible
What symptom results from destruction of mastoids in LCH?
Chronically-draining infected ears
What results from lesions in weight-bearing bones in LCH?
Pathologic fractures
What symptom arises from vertebral body collapse in LCH?
Stooping posture or flank back
What causes the “free-floating teeth” appearance in LCH?
Destruction of mandible and maxilla
What skin symptom may occur in LCH?
Hard-to-treat seborrheic dermatitis
What other systemic manifestations may occur in LCH?
Lymphadenopathies. hepatosplenomegaly. exophthalmos. pituitary dysfunction
What is the first diagnostic step for LCH?
Tissue biopsy from skin or bone lesion
What other tests support the diagnosis of LCH?
CBC. LFTs. coagulation studies. skeletal survey. chest x-ray. urine osmolarity
What is the goal of treatment in single-system LCH?
Arrest progression and prevent permanent damage
What is the typical clinical course of LCH?
Benign with high chance of spontaneous remission
What treatments are used in localized LCH?
Curettage. steroid injection. low-dose radiation therapy
What is the treatment for multisystem LCH?
Systemic multi-agent chemotherapy
What is the cellular characteristic of LCH lesions?
Langerhans-like cells (CD1a+ & CD207+) with Birbeck granules
What is the cellular characteristic of HLH lesions?
Normal reactive macrophages with erythrophagocytosis and CD8+ T cells
What are the cellular characteristics of Juvenile xanthogranuloma?
Vacuolated histiocytes with foamy cytoplasm
What is the cellular hallmark of Rosai-Dorfman disease?
Hemophagocytic histiocytes
What characterizes malignant histiocytosis?
Neoplastic proliferation of monocyte/macrophage-like cells
What classification of leukemia is associated with histiocytosis?
Acute monocytic leukemia (M5 by FAB classification)
What are the histiocytosis types classified under the childhood histiocytoses?
LCH. HLH. Juvenile xanthogranuloma. Rosai-Dorfman disease. Malignant histiocytosis
Which histiocytosis is associated with albinism syndromes?
Hemophagocytic lymphohistiocytosis (HLH)
