Signet ring cell adenocarcinoma of the oropharynx: Presentation of a rare case and review of the literature

Neck Dissection Timing in Transoral Robotic or Laser Microsurgery in Oropharyngeal Cancer: A Systematic Review

Objective

This review assesses the effect on intra- and postoperative patient outcomes of the timing of neck dissection in relation to transoral surgery. Outcome measures include postoperative bleeding, intra- and postoperative fistula formation, and disease-specific and overall survival.

Data Sources

A search was conducted across the MEDLINE, Embase, US National Library of Medicine, and Cochrane databases with search terms in July 2021.

Review Methods

Articles that conformed with specified inclusion criteria were included. Included articles were scanned for bias with the ROBINS-I tool.

Results

Nineteen articles were selected for qualitative analysis, including 546 patients who had neck dissection in conjunction with transoral robotic surgery/transoral laser microsurgery (TORS/TLM). Seventy-one (18%) patients had neck dissection prior to TORS/TLM, 39 (10%) had neck dissection performed after TORS/TLM, and 281 (72%) had concurrent procedures. In patients with neck dissection before TORS/TLM, 3% experienced major postoperative bleeding, and fistula rates were 0%. In the cohort with neck dissection after TORS/TLM, 3% experienced minor postoperative hemorrhage, and 8% had intraoperative fistulae. In the concurrent cohort of patients, 1% had major postoperative bleeds and 0.3% had minor bleeds, while 4% developed intraoperative fistulas and 0.3% developed postoperative fistulas.

Conclusion

Current evidence indicated that there appears to be no correlation between timing of neck dissection and complications. This systematic review found insufficient data to comment on whether the timing of neck dissection in relation to TORS/TLM affects the outcomes of patients.

Salivary Mucinous Adenocarcinoma Is a Histologically Diverse Single Entity With Recurrent AKT1 E17K Mutations: Clinicopathologic and Molecular Characterization With Proposal for a Unified Classification

Mucin-producing salivary adenocarcinomas were historically divided into separate colloid carcinoma, papillary cystadenocarcinoma, and signet ring cell carcinoma diagnoses based on histologic pattern, but have recently been grouped together in the adenocarcinoma not otherwise specified category. It is currently unclear if these tumors represent 1 or more distinct entities and how they are related to well-circumscribed papillary mucinous lesions with recurrent AKT1 E17K mutations that were recently described as salivary intraductal papillary mucinous neoplasm. Here, we sought to evaluate the clinicopathologic and molecular features of salivary mucinous adenocarcinomas to clarify their classification. We identified 17 invasive mucin-producing salivary adenocarcinomas, 10 with a single histologic pattern, and 7 with mixed patterns. While most tumors demonstrated papillary growth (n=15), it was frequently intermixed with colloid (n=6) and signet ring (n=3) architecture with obvious transitions between patterns. All were cytokeratin 7 positive (100%) and cytokeratin 20 negative (0%). Next-generation sequencing performed on a subset demonstrated recurrent AKT1 E17K mutations in 8 cases (100%) and TP53 alterations in 7 cases (88%). Of 12 cases with clinical follow-up (median: 17 mo), 4 developed cervical lymph node metastases, all of which had colloid or signet ring components. Overall, overlapping histologic and immunohistochemical features coupled with recurrent AKT1 E17K mutations across patterns suggests that mucin-producing salivary adenocarcinomas represent a histologically diverse single entity that is closely related to tumors described as salivary intraductal papillary mucinous neoplasm. We propose a unified mucinous adenocarcinoma category subdivided into papillary, colloid, signet ring, and mixed subtypes to facilitate better recognition and classification of these tumors.

Human Papillomavirus (HPV)-Related Carcinoma of the Oropharynx with Squamous Cell and Adenoid Cystic Carcinoma-Like Features: Report of a Case

We describe the heretofore unreported case of an HPV-related carcinoma of the palatine tonsil with distinct areas of squamous cell- and adenoid cystic carcinoma-like differentiation in a 54-year old patient. The morphological, immunophenotypic and molecular findings of the tumor are illustrated. We discuss the parallels between the tumor and HPV-related multiphenotypic sinonasal carcinoma (HMSC) which is well-known to exhibit adenoid cystic carcinoma-like features. A review of the literature of high-risk HPV-associated non-squamous carcinomas of the oropharynx is presented.

High-risk human papillomavirus-mediated adenocarcinoma of palatine tonsil

We describe the case of a human papillomavirus-mediated adenocarcinoma of palatine tonsil in a 51-year-old male. Histologically, the tumor exhibited a predominantly cribriform and tubular (glandular) growth of cuboidal and columnar cells with moderate amount of pale eosinophilic cytoplasm and oval or spindled nuclei with finely dispersed or coarse chromatin and small to medium-sized nucleoli. Foci of nuclear anaplasia and multinucleation, numerous mitotic figures, and necrosis (individual-cell and confluent) were seen. No squamous differentiation was identified. The tumor cells showed strong expression of CK7, p16 and HPV E6/E7 mRNA transcripts, and were negative for p40, CK5/6, AR, synaptophysin and chromogranin. Next generation sequencing showed 3 variants of unknown significance: FGF3 p.(R44fs); NF1 p.(S749 L) and POLE p. (S1506 L) with variant allele frequencies of 37 %; 20 %, and 17 % respectively. Chromosomal microarray analysis using single nucleotide polymorphism microarray (OncoScan) assay showed whole chromosomal gains of chromosomes 8 and 19, whole chromosomal losses of chromosomes 2 and 16, as well as segmental gains of chromosomes 3q25.31q29 (encompassing the PIK3CA gene), 17q21.31q25.3, 20p13q13.33, Xq28, and segmental losses of chromosomes 1q32.2, 6p25.1p21.1, 11q23.1q24.1, 12p11.22, 12p11.22, 14q24.1q32.33, 17p13.3q21.31 (encompassing the TP53 and NF1 genes). The results highlight the need to consider HPV testing in non-squamous cell carcinomas of the oropharynx.

Human papillomavirus-16 associated adenocarcinoma NOS of base of tongue

The causative role of human papillomavirus (HPV) in a subset of squamous cell carcinomas of the oropharynx (OSCC) is now well established with HPV-16 being detected in approximately 92% of HPV-positive OSCC in North America. Recently HPV has also been found in some non-squamous oropharyngeal carcinomas including adenosquamous carcinomas, neuroendocrine carcinomas, and undifferentiated "lymphoepithelioma-like" carcinomas. Herein, we report a HPV-16 positive adenocarcinoma NOS arising in the base of the tongue of a non-smoker, 64 year-old male. To our knowledge, this is the first time this association has been clearly documented. The adenocarcinoma was diffusely positive for p16 and HPV-16 was demonstrated by in situ hybridization and linear array analysis. Q-PCR demonstrated a viral load of 4 copies per cancer cell, whereas qRT-PCR for E6/E7 transcript levels were 30 copies per 1,000 human ribosomal protein large P0 (RPLP0) reference gene. The presence of HPV in non-squamous oropharyngeal carcinomas raises the possibility that HPV is also involved in the carcinogenesis of some uncommon carcinomas of the region.

Signet ring carcinoma parotid gland: a case report

BACKGROUND

Signet ring adenocarcinoma is a recently characterized entity occurring in the minor salivary glands. All reported cases have occurred in minor salivary gland. Pure signet ring adenocarcinoma of a major salivary gland has not been reported in the literature.

METHODS

A 38-year-old woman presented with a mass in the parotid region. Microscopy showed signet ring cells positive for mucicarmine. Immunohistochemistry showed cytokeratin and focal smooth muscle actin (SMA) positivity; an exhaustive search for primary elsewhere did not reveal any suspicious focus.

RESULTS

A diagnosis of low-grade signet ring adenocarcinoma of the parotid gland was made. On 6-month follow-up the patient was alive and well.

CONCLUSIONS

The present case highlights a rare occurrence of this tumor in the parotid gland, which until now was labeled as a tumor exclusive to minor salivary glands. Thus this entity should be kept as a differential while investigating mucinous tumors of parotid.