Cytopathological Findings of Secretory Carcinoma of the Salivary Gland and the Diagnostic Utility of Giemsa Staining

Abstract

Secretory carcinoma is a salivary gland neoplasm first described as a mammary analogue secretory carcinoma by Skalova et al. in 2010 and redesignated as a secretory carcinoma in the 2017 World Health Organization Classification of Head and Neck Tumors. Secretory carcinoma diagnosis is reliant on specific cytological and histological findings and the detection of an ETV6-NTRK3 fusion gene. Here, we examined the clinical and cytopathological features of four cases of secretory carcinoma occurring in three males and a female, aged between 39 and 74 years. All four tumors involved the parotid gland, and were found to have the ETV6-NTRK3 fusion gene. Fine-needle aspiration-based cytology smears of all tumors displayed papillary and/or dendritic pattern clusters, some of which were associated with blood vessels. The neoplastic cells displayed enlarged nuclei with fine chromatin and small, distinct, single nucleoli. Furthermore, several neoplastic cells with a characteristic vacuolated cytoplasm were identified in each specimen. Giemsa staining revealed cytoplasmic vacuolation, intracytoplasmic metachromatic secretions and/or various sized metachromatic granules, and a background of metachromatic mucin in all four specimens. Given this, we conclude that these cytological findings, especially those of the Giemsa staining, might be helpful in the diagnosis of secretory carcinoma.

Secretory carcinoma of salivary gland: A rare tumor masquerading as acinic cell carcinoma on cytology

“…It usually presents as a painless, slow-growing mass in the parotid followed by submandibular, or minor salivary glands. 3 The minority presented with more rapid growth, aggressive involvement of deep structures, or pain. The present case presented with a swelling in the sub-mandibular region for 8 months.…”

Pleural metastasis from parotid secretory carcinoma: First report of morphology on effusion cytology, and role of pan‐TRK immunohistochemistry

“…With increasing access to genetic testing, clinical outcomes of molecularly confirmed SC cases are better documented. Lymph node metastases occur in 5%–25% of cases, but distant metastases are rare, as summarized in Table 2 1,3–16 . Fifteen patients (68%) had metastasis to lungs and/or pleura.…”

“…Lymph node metastases occur in 5%-25% of cases, but distant metastases are rare, as summarized in Table 2. 1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16] Fifteen patients (68%) had metastasis to lungs and/or pleura. Ten (48%) patients died of disease, while 4 (19%) had no evidence of disease at last follow-up; three of the latter had resectable lung metastases.…”

“…Local radiation is administered for large tumors, positive margins or perineural invasion. Regional lymph node metastasis has been described in 5%-25%, [3][4][5][6] while distant metastasis has been documented in 23 patients (Table 1) 1,[3][4][5][6][7][8][9][10][11][12][13][14][15][16] ; systemic chemotherapy may be implemented in these settings. 7,8 ETV6::NTRK3 rearrangement results in overexpression of tropomyosin receptor kinase C encoded by NTRK3.…”

Fine Needle Aspiration Cytology of Secretory Carcinoma of the Parotid Gland in a Young Patient

“…The tumor cells may form macro/microcytic, solid, papillary, micropapillary, and tubular structures. [8][9][10][11] The tumor cells usually tend to have eosinophilic to vacuolated or "soap-like" cytoplasm and vesicular nuclei with a small prominent nucleolus. The recognition of intraluminal located eosinophilic secretions that are periodic acid-Schiff (PAS) positive and diastase resistant in smears is also crucial to a correct diagnosis.…”