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A diagnostic immunohistochemical panel for yolk sac (primitive endodermal) tumours based on an immunohistochemical comparison with the human yolk sac
Author(s) -
Nogales Francisco F,
Quiñonez Enoe,
LópezMarín Laura,
Dulcey Isabel,
Preda Ovidiu
Publication year - 2014
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12373
Subject(s) - yolk sac , immunophenotyping , pathology , immunohistochemistry , biology , endoderm , villin , anatomy , embryo , microbiology and biotechnology , medicine , cellular differentiation , genetics , flow cytometry , actin , gene
Aims To establish a diagnostic immunohistochemical panel for various histotypes of yolk sac (primitive endodermal) tumours ( YST s) by comparison with the human yolk sac ( HYS ) immunophenotype. Methods and results Twenty‐five YST s showing either classical patterns ( CP s) of histology (microcystic/reticular, n = 14; polyvesicular, n = 1; and hepatoid, n = 1) or somatic glandular patterns ( SGP s; n = 9) were analysed for expression of α‐fetoprotein ( AFP ), glypican‐3 ( GPC 3), villin, hepatocyte paraffin‐1 ( H ep P ar‐1), CDX 2, SALL 4 and LIN 28. AFP expression was constantly heterogeneous in CP s but tended to be focal/absent in SGP s. GPC 3 was diffuse in CP s but heterogeneous (seven cases) or focal/absent (two cases) in SGP s. HepPar‐1 expression was focal in all but three cases (diffuse in one CP ‐hepatoid and two SGP s). CDX 2 positivity was focal in CP s but heterogeneous (seven cases) or diffuse (two cases) in SGP s. Villin, SALL 4 and LIN 28 were diffusely positive in nearly all cases. Conclusions CP s reproduce the immunophenotype of HYS and early endoderm with variable expression of both AFP and markers of early gut or hepatic differentiation. SGP s with intestinal differentiation often have incomplete immunophenotypes. A differential diagnosis panel, including both markers of pluripotentiality ( SALL 4 and/or LIN 28) and endoderm ( AFP , GPC 3 and villin), is proposed. It identifies overlapping multidifferentiation of primitive and somatic immunophenotypes, supporting the recently proposed term of primitive endodermal tumours.