Surgical pathology criteria use browser back button to return hibernoma definition tumor of cells with features of brown fat diagnostic criteria circumscribed, lobulated mass grossly yellow-brown cellular features of brown fat numerous small cytoplasmic vacuoles pale to intensely eosinophilic granular cytoplasm normal fat cells may be admixed 7% of cases are predominantly mature fat cytologically bland small central nuclei prominent nucleoli mitotic figures and cytologic atypia rare no clinical significance if present may have myxoid stroma (9% of cases) rarely combined with spindle cell lipoma same clinical features and distribution as usual spindle cell lipoma malignant neoplasms with brown fat differentiation are controversial may represent pleomorphic or myxoid liposarcoma robert v rouse md department of pathology stanford university school of medicine stanford ca 94305-5342 original posting : july 29, 2007 updates: may 25, 2009 supplemental studies immunohistology s100 85%, may be focal cd68 positive cd34 negative unless combined with spindle cell lipoma immunohistochemistry of lipomatous tumors   mdm2 cdk4 p16 atypical lipomatous tumor 45-100% 84-92% 78-97% dedifferentiated liposarcoma 55-95 90-100 90 myxoid / round cell liposarcoma 0-4 0-4 0 pleomorphic liposarcoma 0 0 0 lipoma 0-4 0-2 0 spindle cell and pleomorphic lipoma 0-25 0-6 20 angiomyolipoma 0 0   hibernoma 0 0 positive, variable lipoblastoma 0 (1 case) 0 (1 case) positive (1 case) genetic study frequent rearrangements of 11q13-21 region differential diagnosis fat necrosis lipoblastoma atypical lipomatous tumor myxoid liposarcoma fat necrosis hibernoma poorly circumscribed circumscribed foamy cytoplasm, few vacuoles multiple small vacuoles variable pattern from normal fat to necrotic fat to histiocytes uniform pattern lipoblastoma hibernoma restricted to children at presentation rare in children immature cells and lipoblasts microvesicular brown fat 18q11-13 abnormalities 11q13 abnormalities hibernoma with predominant mature fat atypical lipomatous tumor small, central bland nuclei in vacuolated cells lipoblasts, if present, have atypical nuclei lacks atypical nuclei contains atypical nuclei frequently superifcial rarely superficial mdm2, cdk4, p16 negative mdm2, cdk4, p16 most positive myxoid liposarcoma hibernoma with myxoid stroma rarely superficial frequently superficial prominent "chicken wire" vascular pattern lacks "chicken wire" vascular pattern t(12;16) or t(12;22) 11q13 rearrangement clinical predominantly young adults range 2-. buy cheap viagra online uk canadian pharmacy viagra no prescription cheap generic viagra cheap viagra pills online viagra drug information buy viagra online cheap free shipping where can i buy viagra Male viagra safe women viagra vs. viagra cheap generic viagra Viagra coverage health insurance viagra vs. viagra is prescription required for viagra in canada viagra long acting Viagra expiration safe buy generic viagra viagra samples professionals viagra jovenes yahoo cheap generic viagra viagra vs. viagra viagra used by young men viagra use in children where can i buy viagra over the counter in canada viagra 4 hours viagra generico in farmacia in italia