Lysozyme Expression Can be Useful to Distinguish Mammary Analog Secretory Carcinoma from Acinic Cell Carcinoma of Salivary Glands

Abstract

Lysozyme is an enzymatic marker of acinar and intercalated duct cells of normal salivary glands. The aim of this study was to verify whether lysozyme expression could be useful to distinguish acinic cell carcinoma (ACC) from its main mimic, mammary analog secretory carcinoma (MASC). For comparison, DOG1 expression was analyzed as well. Seventeen cases of ACC, 15 MASC, and 125 other salivary tumors were studied. Lysozyme expression was found in tumor cells as well as in secreted material of MASC (86.6 % of cases) and in ductal cells of epithelial-myoepithelial carcinoma (EMC-53.8 %), pleomorphic adenoma (PA-29.1 %) and polymorphous lowgrade adenocarcinoma (PLGA-23.8 %). However, in ACC, lysozyme was not expressed. Three patterns of DOG1 staining were seen: apical-luminal, cytoplasmic, and mixed cytoplasmic/membranous. The apical-luminal pattern was detected in ductal cells of ACC (58.8 % of cases), EMC (38.4 %), adenoid-cystic carcinoma (AdCC-35.3 %), PA (8.3 %), and PLGA (4.8 %). These tumors also showed mixed membranous/cytoplasmic staining for DOG1. MASC, mucoepidermoid, and salivary duct carcinomas exhibited only DOG1 cytoplasmic staining. In conclusion, lysozyme cannot be used as a marker of acinar differentiation in salivary tumors. However, lysozyme expression can be helpful to distinguish MASC from ACC due to its high frequency in the former and absence in ACC. It is likely that in MASC, lysozyme expression may reflect a lactational-like secretory differentiation since lysozyme belongs to breast milk proteins. Regarding DOG1 expression, the apical-luminal pattern is related to acinar and intercalated duct differentiation whereas the cytoplasmic staining does not seem to be associated with a specific cellular phenotype.

Development and Validation of a 9-Gene Prognostic Signature in Patients With Multiple Myeloma

“…Chen et al demonstrated that PRC1 could promote early recurrence of patients with hepatocellular carcinoma by regulating the expression of FANCI (43). Mariano FV et al demonstrated that the expression of LYZ could be used to differentiate mammary analog secretory carcinoma from acinic cell carcinoma of salivary glands (44). Wu et al demonstrated that the expression of HMGN5 was increased in bladder cancer cells and high expression of HMGN5 was associated with poor prognosis of patients with bladder cancer (45).…”

Ancillary testing in salivary gland cytology: A practical guide

“…The differential diagnosis includes acinic cell carcinoma, mucoepidermoid carcinoma, and adenocarcinoma (primary or metastatic); the majority of cases can be resolved by immunohistochemistry and ETV6 FISH on cell block material. As discussed above, canalicular staining for DOG1 is a feature of acinic cell carcinoma and negative or nonspecific cytoplasmic staining may occur in secretory carcinoma . Acinic cell carcinoma typically is negative for S100 and mammaglobin, although focal staining for either marker may be observed .…”

“…48,49 In contrast, its most frequent mimic, secretory carcinoma, often demonstrates mammaglobin and S100 staining, and usually is DOG1 negative (or may demonstrate nonspecific cytoplasmic staining). 47,[50][51][52][53] Some authors also have reported that carbonic anhydrase VI positivity can distinguish acinic cell carcinoma from secretory carcinoma. 54 Acinic cell carcinoma also is negative for p63, which helps distinguish it from mucoepidermoid carcinoma.…”

“…As discussed above, canalicular staining for DOG1 is a feature of acinic cell carcinoma and negative or nonspecific cytoplasmic staining may occur in secretory carcinoma. 47,[50][51][52][53] Acinic cell carcinoma typically is negative for S100 and mammaglobin, although focal staining for either marker may be observed. 48,49 The cytoplasmic PAS-positive, diastase-resistant basophilic zymogen granules of acinic cell carcinoma are more uniform and finer in quality than the occasional globoid, PAS-positive, diastase-resistant cytoplasmic inclusions of secretory carcinoma.…”

“…Acinic cell carcinoma typically is positive for DOG1, which demonstrates a canalicular staining pattern, and the majority of cases are negative for mammaglobin and S100 . In contrast, its most frequent mimic, secretory carcinoma, often demonstrates mammaglobin and S100 staining, and usually is DOG1 negative (or may demonstrate nonspecific cytoplasmic staining) . Some authors also have reported that carbonic anhydrase VI positivity can distinguish acinic cell carcinoma from secretory carcinoma .…”