A challenging diagnosis of mammary analogue secretory carcinoma (MASC) on fine needle aspiration cytology and cell block: A cytopathologist's perspective

Salivary Gland Secretory Carcinoma; Review of 13 Years World-Wide Experience and Meta-Analysis

OBJECTIVES

Secretory Carcinoma is a malignant salivary gland tumor, initially described in 2010. This rare tumor is associated with the translocation t(12;15) (p13;q25), resulting in the fusion gene ETV6-NTRK3. Since this tumor is quite rare, most publications describe only small cohorts of patients. We aimed to investigate the clinical, pathological, and prognostic features of this newly defined malignant entity.

DATA SOURCES

Pubmed, Google Scholar, and Web of Science databases.

REVIEW METHODS

All published articles between 2010 and 2023 were reviewed. Search terms included the terms "Mammary Analogue Secretory Carcinoma" and "Secretory Carcinoma". All articles published in English reporting on Secretory Carcinoma of salivary glands were retrieved.

RESULTS

One-hundred and 12 retrospective articles reporting a total of 674 patients were included, with 52% males and a mean age of 44.9 ± 18.9. The event rate for patients with advanced-stage disease (Stage 3/4) at presentation was 24.1% (95% CI 17.6%-31.9%, I2  = 9.2%), 14.6% for regional metastases (95% CI 10.5%-20%, I2  = 12%), and the event rate of distant metastasis was 8.4% (95% CI 5.5%-12.7%, I2  = 4.2%). Adjuvant radiotherapy was administered for 30.3% of patients (95% CI 24.1%-37.2%, I2  = 21.5%). The recurrence rate was 19% (95% CI 15.1%-23.8%, I2  = 5%). Survival outcomes showed a 17.2% death of disease rate for Secretory Carcinoma patients (95% CI 13.5%-21.8%, I2  = 7.3%).

CONCLUSIONS

Secretory Carcinoma is a rare and relatively newly defined entity arising in the parotid gland most commonly. Characterized as a low-grade tumor, the majority of patients are diagnosed at an early stage, without regional or distant disease, and the prognosis is relatively good.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1716-1724, 2024.

Acinic Cell Carcinoma of the Breast: A Case Report and Review of Literature

Acinic cell carcinoma (ACC) is an exceedingly rare type of triple-negative breast cancer (TNBC). We are reporting a case of a 46-year-old female patient who presented with a palpable lump in her left breast not associated with pain, pruritis, or change of skin color. An open biopsy revealed a mass of about 20 x 25 mm of fleshy, white tan with a lobular configuration and necrosis. The histopathological examination revealed cells with cytoplasmic granularity arranged in a microglandular pattern and a solid pattern, and the case was initially reported as ACC. The most remarkable feature was the presence of small and large, brightly eosinophilic cytoplasmic granules, and some cells are clear or multivacuolated, resembling lipoblasts. Cellular pleomorphism and anaplasia are very mild, and the mitotic activity was very low. The tumor showed a scant and vascularized stroma in the area of hyalinization. Small clusters of lymphoid infiltration in the stroma were seen. Histochemical stains revealed that the acinar cells in ACC contain abundant diastase-resistant, periodic acid Schiff (PAS)-positive cytoplasmic granules. Mucicarmine and Alcian blue were negative. The immunohistochemistry workup revealed that the case was positive for discovered on gastrointestinal stromal tumors-1 (DOG-1) and the positivity pattern ranged from apical membranous, cytoplasmic, and complete membranous. In addition, the tumor cells were positive for low-molecular-weight cytokeratin, carcinoembryonic antigen (CEA), and epithelial membrane antigen (EMA). The FISH workup for the ETV6-NTRK3 fusion was negative, arguing against secretory carcinoma (SC). A diagnosis of acinar cell carcinoma of the breast is very rare, and the presence of cytoplasmic granules is helpful for its diagnosis. In the absence of these granules, the diagnosis is very difficult, and other diagnoses will be put in the differential diagnosis, particularly SC, lactating adenosis, and microglandular adenosis. Immunohistochemical and histochemical stains and genetic workups will support the diagnosis of ACC.