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NBME 20 Answers

nbme20/Block 2/Question#36
A 31-year-old man has a large, yellow, soft ...
Liposarcoma🔍

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 +5  upvote downvote
submitted by thomas(-2),

Lipomas/Liposarcomas are the commonest soft-tissue tumors in adults. The high mitotic index & infiltrative nature indicate that the mass is malignant.




 +3  upvote downvote
submitted by hayayah(883),

Benign tumors are usually well-differentiated and well-demarcated, with low mitotic activity, no metastases, and no necrosis.

Malignant tumors (cancers) may show poor differentiation, erratic growth, local invasion, metastasis, and apoptosis. High mitotic activity.

Fat tumors:

  • Lipoma: benign, low mitotic activity
  • Liposarcoma: malignant, increased mitotic activity
whossayin  why can't it be a rhabdomyosarcoma? +  
charcot_bouchard  Because of histology and gross appearance... very graphic description of fat cell tumor there +4  
dr_cruceta  because the question said irregular vacuolated cells, describing fat cells. Rhabdomyosarcoma comes from skeletal muscle. +1  



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