Flashcards in Kidney Deck (379)
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210
Nephroblastoma: Immunohistochemistry for WT1.
Blastema and undifferentiated epithelium: Diffuse expression.
Stroma: Little or no expression.
Differentiated epithelium: Variable.
211
Nephroblastoma: Distinction from other tumors of small, round, blue cells (2).
IHC: Expression of WT-1 by nephroblastoma.
EM: Variety of organelles in blastemal cells of nephroblastoma.
212
Nephroblastoma: Sites of metastasis (3).
Lymph nodes, liver, lung.
213
Nephroblastoma: Prognosis (2).
About 90% of cases get cured.
Younger patients do better.
214
Nephrogenic rest:
A. Significance.
B. State of multiplicity.
A. Increased likelihood of contralateral nephroblastoma.
B. Nephroblastomatosis.
215
Nephroblastoma: Histopathology (2).
Perilobar type: Mainly blastema and tubules; very little stroma.
Intralobar type: Rich in stroma.
216
Cystic partially differentiated nephroblastoma: Histopathology (3).
Epithelial-lined cysts or unlined cyst-like structures.
Septa may contain nephroblastomatous epithelium.
No expansile solid component.
217
Cystic partially differentiated nephroblastoma: Variant.
Pediatric cystic nephroma contains no nephroblastomatous elements.
218
Cystic partially differentiated nephroblastoma vs. Cystic nephroblastoma.
The latter has an expansile solid component.
219
Mesoblastic nephroma: Epidemiology (2).
Patients are usually no more than 3 months old.
Most frequent congenital renal neoplasm.
220
Mesoblastic nephroma: Presentation.
Abdominal mass.
221
Mesoblastic nephroma: Behavior (2).
Excellent if completely resected.
222
Mesoblastic nephroma: Location.
Renal sinus.
223
Mesoblastic nephroma: Gross pathology (2).
Classic: Small; firm; resembles leiomyoma.
Cellular: Large; soft; cystic; focally hemorrhagic and necrotic.
224
Mesoblastic nephroma: Histopathology of classic type.
Resembles benign fibromatosis.
225
Mesoblastic nephroma: Histopathology of cellular type.
Sheets or vague fascicles of densely packed, plump, mitotically active cells.
Same as infantile fibrosarcoma.
226
Mesoblastic nephroma: Immunohistochemistry (2).
Positive: SMA, vimentin.
227
Mesoblastic nephroma: Electron microscopy.
Much endoplasmic reticulum.
228
Mesoblastic nephroma: Translocation.
t(12;15)(p13;q25).
229
Mesoblastic nephroma vs. cystic nephroma.
Mesoblastic nephroma: Spindle-cell mesenchymal tumor in infants.
Cystic nephroma: Bland cysts and ovarian-type stroma; occurs mainly in women.
230
Mesoblastic nephroma vs. metanephric adenoma.
Mesoblastic nephroma: Spindle-cell mesenchymal tumor in infants.
Metanephric adenoma: Small acini consisting of small, dark cells; occurs in adults.
231
Clear-cell sarcoma: Age group.
Between 6 months and 5 years.
232
Clear-cell sarcoma: Cytology of classic type (3).
Cytoplasm: Pale.
Nucleus: Vesicular.
Nucleolus: Inconspicuous.
233
Clear-cell sarcoma: Histopathology of classic type (2).
Cells form cords that are separated by regularly spaced fibrovascular arcades.
Normal renal structures are entrapped at the periphery of the tumor.
234
Clear-cell sarcoma: Variants (3).
Myxoid, sclerosing, epithelioid, many others.
235
Clear-cell sarcoma: Immunohistochemistry (2,3).
Positive: Vimentin, nerve-growth-factor receptor.
Negative: Cytokeratins, neural markers, WT1.
236
Clear-cell sarcoma: Prognosis.
Very aggressive.
237
Rhabdoid tumor: Age at presentation.
Usually less than 2 years.
238
Rhabdoid tumor:
A. Laboratory findings.
B. Associated tumor.
A. Hypercalcemia, hematuria.
B. PNET of the posterior fossa.
239