Among less commonly used antibodies, reactivity to mesothelin was found in 28 of 30 cases (93%); HBME1, 28 of 30 (93%); WT1, 22 of 27 (81%); D2-40, 20 of 22 (91%); and cytokeratin 5, 18 of 18 (100%).
Malignant mesothelioma cells also express podoplanin (D2-40) (e), HBME1 (f), and mesothelin (g) as markers of the mesothelial lineage, whereas there is no reactivity to carcinoembryonic antigen (CEA) (h), thyroid transcription factor 1 (TTF-1, absent brown nuclear staining) (i), or Napsin A (red) (i).
Abbreviations: CITED1, CREB-binding protein/ p300-interacting transactivator with Asp/Glu-rich C-terminal domain 1; CK19, cytokeratin 19; FA, follicular adenoma; FC, follicular carcinoma; FTUMP, follicular tumor of undetermined malignant potential; FVPTC, follicular variant of papillary thyroid carcinoma; Galectin-3, galactoside-binding lectin soluble 3;
HBME1, Hector Battifora mesothelial 1; IMP3, insulin-like growth factor II messenger RNA binding protein 3; PTC, papillary thyroid carcinoma.
Reduced
HBME1 immunoreactivity of papillary thyroid carcinoma and papillary thyroid carcinoma-related neoplastic lesions with Hurthle cell and/or apocrine-like changes.
Cytokeratin 19 expression was cytoplasmic, CITED1 expression was nuclear and cytoplasmic, and HBME1 expression was membranous, apical, and cytoplasmic (Figure 2, A through D).
High-Density TMA.--Only 4 follicular adenomas (of 26) and 1 goiter (of 27) were positive for HBME1 on the TMA (5 of 80), whereas the corresponding whole section immunohistochemistry showed positive expression in 9 cases (1 of 8 FTCs, 4 of 26 adenomas, and 4 of 27 goiters).
The cumulative core loss for CK 19, HBME1, and CITED1 was 10% in HD-TMA and 13% in LD-TMA.