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57 Cards in this Set
- Front
- Back
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What causes defects during the first trimester?
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chromosomal abnormalities, genetic mutations
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What causes defects in the second and third trimesters?
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maternal diseases
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When do myofibromas present?
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any time, many in first two years of life
male predominance |
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How do myofibromas present in neonates?
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cutaneous or subcu masses, bright red
also as large and disfiguring |
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What is the prognosis of myofibroma?
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most are benign, rapid growth at first, spontaneous involution later
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What do myofibromas look like grossly?
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rubbery firm nodules from .5-7cm
cut surface is grey-white to tan-brown and red |
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What do myofibromas look like microscopically?
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whorls or short fascicles of myoid spindle cells, centered around thin walled vessels
myofibroblasts are spindled |
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With what can you stain myofibromas?
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muscle actin, vimentin, Pan-actin HHF-35
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With what can you not stain myofibromas?
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desmin, EMA, cytokeratin, S100
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Who gets fibrous hamartomas?
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first two years of life
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How do fibrous hamartomas of infancy present?
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fast growth at first, firm subcutaneous solitary mass, less than 5cm diameter
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Where do fibrous hamartomas commonly present?
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axilla, upper arm, shoulder, thigh, groin, back, forearm
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What is the prognosis of fibrous hamartoma of infancy?
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needs, but responds well to surgery, occasionally recur
grow rapidly in first 5 years, growth slows down |
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What does a fibrous hamartoma of infancy look like microscopically?
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fibrous septae of long, spindle cells, mature adipose tissue, whorls, islands, nests of immature spindle cells
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How does a Gardner fibroma present?
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poorly defined rubbery subcutaneous plaque
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In whom do Gardner fibromas present?
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children 3-14 years old
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Where do Gardner fibromas occur?
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subcu masses in paraspinal region or back, surround normal structures
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What does a Gardner fibroma look like microscopically?
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hypocellular band of dense collagen forming wavy strands separated by crack-like artifact
spindle cell nuclei, occasional mass cells |
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For what do Gardner fibromas stain?
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CD 34, beta-catenin over expression
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For what are Gardner fibromas negative?
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smooth muscle actin, muscle specific actin, estrogen receptor, progesterone receptor
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What is a Gardner fibroma a sign of?
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FAP, mutation in the APC gene
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How does FAP present?
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interstitial polyposis, bone and soft tissue lesions: osteomas, epidermal inclusion cysts, lipomas, fibromas, desmoid tumors
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What is the most common extracranial neoplasm in the first two years of life?
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neuroblastoma
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When do neuroblastomas usually arise?
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before age 2
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How do neuroblastomas present?
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large abdominal mass, elevated catecholamine levels
can have blueberry muffin rash or paraneoplastic syndrome |
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With what tumor is the blueberry muffin rash associated?
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neuroblastoma
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What does a neuroblastoma look like grossly?
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well circumscirbed, can be maroon and soft to tan-pink and firm
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What does a neuroblastoma look like microscopically?
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poorly differentiated blue round cells with high N/C ration, no stroma, interstitial hemorrhage to neural differentiation with rosettes
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What do well differentiated neuroblastomas look like microscopically?
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Schwannian stroma with differentiating neuroblasts, differentiated ganglion-like cells
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What scale is used to determine prognosis of neuroblastomas?
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Shimada classification
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What are the most important prognostic indicators of neuroblastomas?
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MYCN amplification, age of patient and stage of lesion
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What oncogene is common in neuroblastomas?
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MYCN
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What other factors affect neuroblastoma prognosis?
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catecholamine level, histology, deletion of 1p36.2-3, ploidy
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What is the most common renal tumor in children?
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Wilms tumor
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How does Wilms tumor present?
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around 3 years, rarely multifocal or bilateral
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What is WAGR syndrome?
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Wilms tumor, aniridia, genital anomalies, mental retardation, germline deletion of 11p13
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What is Denys-Drash syndrome?
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gonadal dysgenesis, early onset nephropathy, gonadoblastomas, germline mutation in WT1
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What is Beckwith-Wiedemann syndrome?
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macroglossia, hemihypertrophy, omphalocele, adrenal cytomegaly, tumors
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What is the defect of Beckwith-Wiedemann syndrome?
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11p15.5
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What do you see grossly with Wilms tumor?
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large renal mass, soft, cystic, hemorrhagic, necrotic changes
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What does Wilms tumor look like histologically?
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small round blue cells, tubules or rosettes, mesenchymal spindle cell part, mitoses
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What are unfavorable histologic signs in Wilms tumor?
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atypical mitoses, large hyperchromatic nuclei
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What is the most common soft tissue sarcoma in kids?
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rhabdomyosarcoma
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What makes up rhabdomyosarcomas?
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cells with early skeletal muscle differentiation, can arise from primitive mesenchyme in places not commonly skeletal muscle
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What are the most common sites of rhabdomyosarcoma?
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head and neck, GU, limbs
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With what syndromes are rhabdomyosarcomas associated?
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neurofibromatosis type 1, FAP, Beckwith-Wiedemann syndrome, Gorlin nevoid basal cell carcinoma syndrome
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What are the types of rhabdomyosarcomas?
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embryonal, alveolar, pelomorphic
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What is the typical genetic abnormality of alveolar rhabdomyosarcoma?
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PAX3-FKHR, PAX7-FKHR
t(2;13), t(1;13) |
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What is the common genetic abnormality of embryonal rhabdomyosarcoma?
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loss of heterozygosity at 11p15.5
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Which rhabdomyosarcomas have the best prognosis?
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embryonal NOS
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What type of rhabdomyosarcoma has a bad prognosis?
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alveolar rhabdomyosarcoma
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What is the most common type of rhabdomyosarcoma?
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embryonal
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Where do embryonal rhambdomyosarcomas present?
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head and neck region, then GU tract
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What does a rhabdomyosarcoma look like in histo?
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small blue round cells, round, oval, spindle, or polygonal nuclei
sheet-like arrangements, fascicles |
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Where does alveolar rhabdomyosarcoma involve?
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extremities, head and neck
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What do alveolar rhabdomyosarcomas look like?
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pale-yellow to white, frequent soft/hemorrhagic areas
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What is the microscopic appearance of alveolar rhabdomyosarcoma?
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larger cells with more pleomorphic nuclei
adhesive to fibrous septae, less cohesive |
