Comparison of p63/p40 Expression With Myoepithelial Markers in Minor Salivary Gland Tumors

Abstract

The present study aimed to compare the expression of p63/p40 with smooth muscle actin (SMA) and vimentin (VIM) by myoepithelial cells in minor salivary gland tumors. Fifty-two formalin-fixed paraffin-embedded samples of minor salivary gland tumors derived from intercalated duct (pleomorphic adenoma [PA], adenoid cystic carcinoma [ACC], epithelialmyoepithelial carcinoma [EMC], polymorphous adenocarcinoma [PAC], and secretory carcinoma [SC]) and 3 samples of minor salivary gland tumors derived from excretory duct (mucoepidermoid carcinoma [MEC]) were evaluated by means of immunohistochemistry. The data were analyzed qualitatively. The results indicated that p63 and p40 expression were detected in myoepithelial cells present in PA, ACC, and EMC. However, both proteins were also observed in squamous areas of PA and all cases of MEC. SMA were noticed in some myoepithelial cells of PA, ACC, and EMC. Expression of SMA was negative in the other salivary gland tumors evaluated. VIM was constantly expressed by myoepithelial cells in PA, ACC, and EMC. VIM was also observed in cells of PAC and SC, but not in squamous areas of PA and MEC. In conclusion, p63 expression is almost comparable with VIM in detecting myoepithelial cells, an immunolabeling pattern not followed by p40, and consequently, caution has to be taken during the interpretation of salivary gland tumor exhibiting an p63/p40 phenotype in order to avoid a misdiagnosis.

Epithelial–myoepithelial carcinoma of the nasopharynx: A case report and review of the literature

“…Compared with the low specificity of radiologic imaging, immunohistochemistry is useful for distinguishing EMCa, as it can depict the characteristic biphasic epithelialmyoepithelial phenotype and the differential staining of markers in each layer; thus, it plays a major role in the final diagnosis (2,10). IHC staining of glandular epithelial markers such as CK, epithelial membrane antigen (EMA), and CD117 (11) and myoepithelial markers such as SMA, S-100 protein, Actin, VIM, CK14, GFAP and Calponin, and P63 is observed (45)(46)(47). Kawahara et al suggested that P63 is an especially useful marker of myoepithelial cells with naked nuclei in EMCa (48).…”

Pulmonary sialadenoma papilliferum and its mimics: what you need to know

“…The different immunophenotype of the abluminal cells may simply represent two different differentiations from ductal progenitor cells. Moreover, although SMA is a sensitive marker for myoepithelial differentiation it should not be the sole myoepithelial marker, because any cell with substantial expression of actin can be positive for SMA due to its low specificity 15 . To date, only one case has shown SMA staining in abluminal cells, and further research is necessary to characterise these cells in pulmonary SP.…”

“…Moreover, although SMA is a sensitive marker for myoepithelial differentiation it should not be the sole myoepithelial marker, because any cell with substantial expression of actin can be positive for SMA due to its low specificity. 15 To date, only one case has shown SMA staining in abluminal cells, and further research is necessary to characterise these cells in pulmonary SP. SOX10 was strongly expressed in both luminal and basal cells in all five cases with staining (100%) (Figure 2D).…”