Mesenchymal Tumors MESENCHYMAL TUMORS OF Focus on Vascular Tumors - PowerPoint PPT Presentation

5/23/2014 Mesenchymal Tumors MESENCHYMAL TUMORS OF Focus on Vascular Tumors THE LIVER: � Benign and the “Probably Benign” WHAT’S NEW AND UNUSUAL � Newly-described and variant lesions (MY PERSPECTIVE) � Malignant � Distinction of benign/low grade lesions from Angiosarcoma � What is NOT Angiosarcoma CURRENT ISSUES IN ANATOMIC Focus on Angiomyolipoma: Problem PATHOLOGY variants that still lead to diagnostic errors MAY 23, 2014 � Epithelioid, inflammatory, trabecular Linda Ferrell, MD, UCSF VASCULAR TUMORS Cavernous Hemangioma Variants The Benign and Probably Benign HEMANGIOMA VARIANTS VASCULAR MALFORMATIONS 1

5/23/2014 Cavernous Hemangioma (CH) Cavernous Hemangioma Incidental (Autopsy Giant CH, with organized Not true arterial finding thrombosis and sclerosis or venous architecture No organized muscle bundles No elastic laminas Not capillary-like Cavernous Hemangioma: Sclerosis within Cavernous Hemangioma What is often “not seen”…. Sclerosis of � Hemangioma-like vessels (HLV) in thrombosed, adjacent liver commonly seen with giant ischemic zones CH with scar formation. � Ref: Kim GE, Thung SN, Tsui WMS, Ferrell LD. Hepatic Cavernous Hemangioma: Under-Recognized Associated Histologic Features. Liver Int'l, 26:334-38, 2006. “Neo-vessels” � Low mitotic/proliferative rate <5% Recanalized � Present in almost 80% (16/19) of CH >5 cm channels � Retain composition of vascular walls in CH 2

5/23/2014 Cavernous Hemangioma-like vessels in Giant Cavernous Hemangioma adjacent liver Giant Cavernous Hemangioma Giant Cavernous Hemangioma Explant, right Left Lobe: lobe Smaller, irregularly 38 yr old shaped CHs and woman, in liver transitional areas failure. with HLVs admixed with liver 3

5/23/2014 “Metatastatic” and “Invasive” Giant Cavernous Hemangioma Cavernous Hemangioma Lesion extending into hilum around Omental Lesion Right Lobe CH Left lobe HLV arteries, nerves and ducts Nerve Duct Artery Cavernous Hemangioma Variant Vascular Malformations Diagnoses: Giant Cavernous Hemangioma and � Hereditary Hemorrhagic Telangiectasia Cavernous Hemangiomatosis (HHT) arterial-venous malformations � CH-like vessels throughout liver, involving � also known as Osler-Weber-Rendu hilum � Lung, spleen, omentum involved with CH-like lesions � Other Arterial and Venous Malformations with similar features Problematic cavernous hemangioma variants and other benign mimics: A Mattis, S Fischer, H Makhlouf, W Tsui, S Cho, L Ferrell. Poster at � (may or may not be HHT) USCAP Mar 2010, published Mod Pathol Supple 1, 2010. 4

5/23/2014 Vascular Malformations Vascular Malformations Contributors and co-authors of 2 abstracts : Early or mild lesions can look Spectrum: � Cho S, Paradis V, Pai R, Bioulac-Sage P , Alves V, Souza T, much different than advanced or Makhlouf H, Schirmacher P , Evason K, Ferrell L. Early, mild Histopathologic Features of Extensive Hepatic Vascular severe lesions probably primarily Malformations. Mod Path 23 (Supple 1):352A, 2010. To due to thrombosis and ischemic Late, severe effects � Cho S, Wanless I, Sempoux C, Paradis V, Pai R, Thung S, Bioulac-Sage P , Balabaud C, Makhlouf H, Schirmacher P Alves V, Souza T, Evason K, Ferrell L. FNH-Like Lesions and Glutamine Synthetase Expression in the Liver in Hereditary Hemorrhagic Telangiectasia. Mod Path, 24 (Supple 1):358A, 2011. Vascular Malformations: Vascular Malformations: Early Lesions or Mild Involvement More Severe or Advanced Lesions Periportal fibrosis, Elastochrome Periductal fibrosis (as early Thrombosis within vessels and Extension of lesions into sinusoids stain ischemic lesion) sinusoids 5

5/23/2014 Vascular Malformations: Vascular Malformations More Severe or Advanced Lesions Severe sinusoidal changes Hemangioma-like changes, Cavernous hemangioma-like extensive sinusoidal dilation transformationn Small Vessel Hemangioma Small Vessel Hemangioma Small channels, thin walls, � Small vascular channels with thin Only focal fibrotic areas Rare bland nuclei walls (no wide walls as in CH) � Bland endothelial cells with low proliferative rate <10% (CH <5%) Newly described � Intermediate tumor cell density � Irregular “infiltrative” growth pattern at border � abnormal liver architecture mimics HCC � scaffolding effect mimics angiosarcoma 6

5/23/2014 Small Vessel Hemangioma Small Vessel Hemangioma Center of lesion, bland Edge of lesion, with Small channels with thin walls, no Low Mib1 (Ki-67) rate organized muscle endothelial cells altered cell plate width Small Vessel Hemangioma Small Vessel Hemangioma � Small vessel hepatic hemangioma (SVH): Exact outcome not Edge of lesion, trichrome Edge of lesion, reticulin definitive, so now recommending excision and followup. � Differentiation from angiosarcoma: AS has higher proliferative rate (>15%) and subset + for P53 and GLUT1, but negative in small vessel hemangioma References � Gill R, Sempoux C, Makhlouf H, Thung S, Alves V, Ferrell L. Small Vessel Hepatic Hemangioma Variant in Adult Liver. Mod Pathol 25(Supple 2): 413A, 2012. � Gill R, et al. GLUT-1 expression in adult hepatic vascular neoplasms. Mod Pathol 26(Supple 2): 2013. 7

5/23/2014 Epithelioid Hemangioendothelioma Malignant Vascular Tumors Epithelioid Hemangioendothelioma Epithelioid Hemangioendothelioma Epithelioid Hemangioendothelioma Elastochrome stain*, Angiosarcoma- like pattern of scaffolding growth Central vein invasion central vein invasion *Elastochrome: trichrome plus EVG stain; highlights vein wall elastic fibers 8

5/23/2014 Angiosarcoma � Most aggressive form of vascular Angiosarcoma malignancy � Highest proliferative rate � Epithelioid or spindle cell forms � Cystic and/or solid � Known for the typical feature of “scaffolding” growth pattern Angiosarcoma Angiosarcoma Epithelioid pattern High MiB1 (Ki-67) rate 9

5/23/2014 Angiosarcoma Angiosarcoma Scaffolding growth pattern CD34 and expanded Cystic change along sinusoids sinusoidal growth Congestion Necrosis Sinusoidal growth Angiosarcoma (higher magnification) Angiosarcoma Scaffolding Cystic change pattern of (upper right) growth Congestion surrounds hepatocytes Necrosis Sinusoidal growth 10

5/23/2014 Angiosarcoma Angiosarcoma Scaffolding Scaffolding pattern of pattern of growth growth with surrounds fibrosis of cell hepatocytes plate areas Angiosarcoma Angiosarcoma: Highlights � High proliferative rate and cytologic atypia Sinusoidal growth � - Early pattern of growth typically along sinusoids results in (scaffold-like); Atypical endothelial cells, dilated anastomosing channels and sinusoids pseudopapillary � - Later pattern of growth can be pseudopapillary to pattern solid; irregularly-shaped blood filled spaces � - Lacks the stromal prominence of epithelioid hemangioendothelioma, but overlapping cases may be seen 11

5/23/2014 Undifferentiated (Embryonal) Sarcoma Typically younger patients; tumor of uncertain etiology What else is NOT angiosarcoma Can be cystic due to necrosis/degeneration with irregular edges!! (Pattern similar to angiosarcoma scaffolding) Immunohistochemistry Undifferentiated (Embryonal) � Reactive with alpha-1-antitrypsin, alpha-1- antichymotrypsin, vimentin Sarcoma of the Liver � Occasional cytokeratin positivity � Some CD10 and p53 positivity � Negative hepatocyte-Ab, muscle, S-100 and CD34 � Ref: Kiani B, Ferrell LD, Qualman S, Frankel WL. Immunohistochemical Analysis of Embryonal Sarcoma of the Liver. Applied Immunohistochem Mol Morphol 14:193-7, 2006. � Glypican-3 can be positive in giant cells (personal observation) Undifferentiated (Embryonal) Sarcoma Undifferentiated (Embryonal) Sarcoma Cystic areas common Related to extensive necrosis (right upper area) 12

5/23/2014 Undifferentiated sarcoma, tumor edge Undifferentiated Embryonal Sarcoma with growth along sinusoids Problem with Literature Search PASD + globules Also Alpha-1-antitrypsin + � Int J Surg Pathol. 2012 Jun;20(3):297-300. Embryonal (undifferentiated) sarcoma of the liver with peripheral angiosarcoma differentiation…. � THIS IS NOT THE CORRECT DIAGNOSIS as per three expert consultants � Authors got confused about peripheral growth Problem Case Angiomyolipoma � 37-year-old woman � 11 cm pedunculated Problem variants mass Epithelioid, Trabecular, and � No cirrhosis or other Inflammatory risk factors for HCC � Mass noted during routine gynecologic exam, no symptoms 13

5/23/2014 Reticulin Stain HCA, HCC? Reticulin Stain: too much loss for HCA HCC or Not? 14

5/23/2014 Keratin and HMB-45 Angiomyolipoma, epithelioid variant Ref: Tsui WMS, et al. Hepatic Angiomyolipoma: Delineation of Unusual Morphological Variants. Amer J Surg Pathol, 23:34-48, 1999. Angiomyolipoma Angiomyolipoma Epithelioid Cells Spindle Cells Classic features: Fat, Epithelioid, Spindle cells 15

5/23/2014 Problem Case: Angiomyolipoma Trabecular Angiomyolipoma HMB-45: stains stronger SMA: usually stains HMB-45 on epithelioid cells spindle cells Problem case: Problem case: Angiomyolipoma Inflammatory Angiomyolipoma Inflammatory and Trabecular Focal dense to scattered diffuse T-cell infiltrate Case with both inflammatory and “trabecular” background 16