Searching for Mammary Analog Secretory Carcinoma of Salivary Gland Among Its Mimics

Andre Pinto; Vania Nosé; Claudia Rojas; Yao-Shan Fan; Carmen Gomez-Fernandez

Disclosures

Mod Pathol. 2014;27(1):30-37. 

In This Article

Results

FISH studies confirmed ETV6-NTRK3 rearrangement in 3 of the 10 cases. These three tumors had been initially diagnosed as acinic cell carcinoma. Immunohistochemistry studies demonstrated that each was positive for S-100 and mammaglobin and negative for ANO1 (Table 2).

The ages for the three patients with tumors harboring the ETV6-NTRK3 translocation ranged from 29 to 61 years (average 47.6, median 53 years). Two of the patients were male. Grossly, the tumors were generally described as circumscribed, gray-tan cystic masses, and ranged from 1.8 cm to 3.0 cm in greatest dimension. Histologically, all cases demonstrated a mixture of micropapillary, microcystic, and solid patterns of growth with an overall lobulated architecture. The microcystic spaces contained characteristic eosinophilic bubbly secretions, whereas the micropapillary growth pattern consisted of tumor cells surrounding a fibrovascular core in a 'hobnail' pattern. The tumor cells had minimal nuclear pleomorphism with abundant eosinophilic or vacuolated cytoplasm. No necrosis, perineural, or lymphovascular invasion was identified in any of the cases in our series. Lymph node metastasis was present in one confirmed case on which node dissection was performed. No distant metastases were identified at the time of presentation in any of patients (Figure 3).

Figure 3.

Adenocarcinoma, NOS. Although this case had areas that resembled MASC-like abundant eosinophilic cytoplasm, nuclear pleomorphism and histological grade were higher than typically seen on this recently recognized entity. This case was also strongly positive for S-100 (b). a: H&E, x400 original magnification, b: x200 original magnification.

With respect to the other cases in our study subjected to FISH analysis and immunohistochemistry, one case demonstrated amplification of the ETV6 gene, and one case had deletion of ETV6. Both of these cases belonged to male patients. The remaining five cases had no cytogenetic abnormalities detected. By immunohistochemistry, the three cytogenetically confirmed cases were positive for S-100 and mammglobin and negative for DOG1. Interestingly, there was one other case with the same immunohistochemistry results, which was morphologically compatible with mammary analog secretory carcinoma, but failed to demonstrate the characteristic ETV6-NTRK3 translocation.

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