Secretory carcinoma of salivary type in a lymph node presenting as a neck cyst diagnosed by cytology: A case report

Abstract

Secretory carcinoma (SC) is a relatively recently described salivary gland adenocarcinoma characterized by ETV6‐NTRK3 gene fusion and, in most cases, indolent clinical behavior. Morphologically, the tumor shows a glandular architecture and the presence of monophasic tumor cells with vacuolated cytoplasm, low‐grade nuclear atypia, and mucin production, with possibly a tubular, papillary, or cystic arrangement. In this article, we describe a case of a 52‐year old man with SC involving a neck lymph node clinically manifesting as a slowly growing cystic neck mass without recent proof of the primary tumor, but with a history of a parotid gland “cystadenopapilloma,” which had been removed 35 years prior. A fine‐needle aspiration biopsy revealed a diagnosis of SC. Subsequent histopathological examination after lymph node dissection confirmed the diagnosis. The tumor showed typical features of SC, including immunohistochemical positivity for NTRK and NTRK3 gene rearrangement, detected using in situ hybridization. We discuss that the tumor may be a late metastasis occurring 35 years after resection of undiagnosed salivary SC or a primary SC arising from heterotopic salivary tissue within a lymph node. Differential diagnostic considerations and review of relevant literature are included.

Metastatic Mammary Carcinoma Presenting as a Large Cystic Axillary Mass: A Report of an Unusual Case

“…This occurs most frequently in lymph nodes of head and neck region, followed in decreasing frequency in inguinal, axillary, supraclavicular, and intrathoracic areas. 6,9,18 The primary tumors include papillary thyroid carcinoma, 1,2,3,4 malignant melanoma, 10 rectal adenocarcinoma, 5 pulmonary non-small cell carcinoma (squamous and adenocarcinoma), 6 salivary gland mammary-analogue secretory carcinoma, 7 tonsillar/oro/nasophanynx squamous cell carcinoma, 8,18 vulvar and other cutaneous squamous cell carcinoma, 9 and serous carcinoma of the gynecologic tract. 9 Within the literature for mammary carcinoma, only one previous report was identified.…”

“…Although uncommon, some metastatic cancers can present as cystic masses within lymph nodes. Cystic metastatic tumor deposits to lymph nodes have been described in patients with metastatic carcinoma of thyroid, 1,2,3,4 rectum, 5 lung, 6 salivary gland, 7 Waldeyer's ring, 8 and gynecologic tract origin, 9 as well as metastatic melanoma. 10 Cystic lymph node metastases of mammary carcinoma have been rarely reported.…”

What Is New in Biomarker Testing at Diagnosis of Advanced Non-Squamous Non-Small Cell Lung Carcinoma? Implications for Cytology and Liquid Biopsy

“…At the moment, most of the major studies use tissue samples for NTRK status assessment [109][110][111]. However, detection can be possible with cytological samples and even liquid biopsies [109,[112][113][114][115]. Several techniques of detection have been developed, including immunohistochemistry (IHC), molecular biology approaches (NGS and RT-PCR), and multiplex digital colorcoded barcode technology on tissue sections .…”

“…Depending on the quality and quantity of the nucleic acids extracted from the sample, false negative results can be obtained [78,81,109,119,121]. Depending on the case, these approaches could be performed with cytological samples, but only a few studies in this area have been performed to date and studies comparing cytological and tissue samples are strongly needed [109,[112][113][114][115]. The detection of NTRK fusions can also be envisaged with a liquid biopsy, but the sensitivity of such an approach is still unknown and needs to be determined.…”

“…Targeted RT-PCR approaches are no longer used and have been replaced by multiplex RT-PCR methods as well as by DNA-and RNA-based NGS or even multiplex analytical techniques on the NanoString platform [136,[150][151][152][153]. The major limitation of DNA-based NGS lies in the absence of information into effective transcription of the rearranged RET gene [113]. This approach presents a problem for RET rearrangements since they have an unusual breakpoint in RET or have a fusion partner that has never been previously characterized or identified [154].…”