[1573] Immunohistochemical Classification of Hepatic Adenomas and Atypical Hepatocellular Neoplasms: Correlation with Clinicopathologic Characteristics and Chromosomal Abnormalities

K Evason, J Grenert, L Ferrell, S Kakar. UCSF, San Francisco, CA

Background: The distinction of hepatic adenomas(HA)from hepatocellular carcinoma(HCC)is difficult in males,elderly women,or when focal atypical features are present.These tumors can show chromosomal abnormalities(Chr Abn)typical of HCC and can recur or metastasize.Recently,HAs have been classified based on inflammatory features and β-catenin(βC)pathway abnormalities.The latter may have higher risk for progression to HCC.We examine the relationship of SAA expression and βC abnormalities with clinicopathologic features and Chr Abn.
Design: Immunohistochemistry for βC,glutamine synthetase(GS)and serum amyloid associated protein(SAA)was done in 23 HA,36 AHN and 18 well-differentiated HCC.AHN was used for HA-like tumors in men,women >50 or <15 years and/or with focal atypia(small cell change,pseudoglands,thick plates).Tumors with nuclear βC and/or diffuse GS were regarded as βC abnormal.Chromosomal gains/losses had previously been determined in 39 cases using CGH or FISH.
Results: βC and Chr Abn in AHNs were more common than HA,but were similar to HCC(table1).HAs and AHNs with abnormal βC were associated with atypical morphology(table2).Follow-up data was limited but adverse outcome was observed in 3 tumors with abnormal βC(2 recurrences,1 metastasis);in addition,transition to areas of HCC was observed in 2 cases.Chr Abn were more often seen in tumors with abnormal βC(89%vs12%,p<0.001).

	Inflammation	Telangiectasia	βC abnormal	SAA +	Chr Abn
HA	45	41	6	63	0
AHN	36	33	44	62	53
HCC	-	-	50	29	55
p value	0.17	0.19	0.003,0.21	0.58,0.03	0.007,0.3

Figures reflect percentages;p values are AHN vs HA,AHN vsHCC

	Atypical age/sex	Atypical morphology	Inflammation	Telangiectasia	Chr Abn
βcatenin abn vs normal	43 vs 30	71 vs 20	35 vs 44	35 vs 38	89 vs 12
p value	0.17	<0.001	0.2	0.23	<0.001
SAA positive vs negative	43 vs 22	33 vs 42	48 vs 26	45 vs 21	50 vs 38
p value	0.12	0.37	0.1	0.08	0.47

Conclusions: Most adenoma-like neoplasms with βC abnormalities detectable by immunohistochemistry showed atypical morphological features,and were associated with Chr Abn typical of HCC.Some of these tumors can recur and metastasize.It is likely that these tumors represent extremely well-differentiated HCC.SAA expression shows borderline significant correlation with inflammation and telangiectasia,but not with atypical morphological features or Chr Abn.
Category: Liver & Pancreas

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 223, Tuesday Morning