Adenoid cystic carcinoma of the sublingual gland developing lung metastasis 20 years after primary treatment: A case report and literature review

Very late intracranial extraparenchymal solitary metastasis of adenoid cystic carcinoma of the parotid gland: A case report and literature review

Background

Adenoid cystic carcinoma (ACC) of the parotid gland often manifests as distant metastasis long after the initial surgery, resulting in a poor long-term prognosis. The most common sites of metastasis are the lungs, liver, and bones. Single intracranial metastasis is very rare.

Case Description

A 43-year-old woman with a history of surgical removal of ACC 24 years prior presented with Gerstmann syndrome and right hemianopsia. Head magnetic resonance imaging revealed a solitary extra-axial tumor in the left occipital region. The tumor was surgically removed and pathologically diagnosed as a metastasis of cribriform-type ACC. Since she had no other systemic metastasis, she did not receive adjuvant treatment and has remained recurrence-free for 35 months postoperatively.

Conclusion

Very late intracranial solitary metastasis of ACC is extremely rare. Due to the risk of delayed recurrence in pathologically confirmed cribriform type ACC, long-term follow-up is recommended.

Malignant sublingual gland tumors: A single-center retrospective analysis of 79 patients

OBJECTIVES

To analyze and summarize the clinicopathological features, risk factors for cervical nodal metastasis, and prognostic factors of malignant sublingual gland tumors (MSLGT).

METHODS

Patients diagnosed with MSLGT were retrospectively reviewed from January 2005 to December 2017 at Shanghai Ninth Hospital. The clinicopathological features were summarized, and the correlations between clinicopathological parameters, cervical nodal metastasis, and local-regional recurrence were evaluated using the Chi-square test. Kaplan-Meier method and Cox regression analysis were performed to assess the survival and independent prognostic factors.

RESULTS

Seventy-nine patients were included, and the 5-year overall survival and disease-free survival rates was 85.7% and 71.7%, respectively. Gender and clinical tumor stage were risk factors for cervical nodal metastasis. Tumor size and pathological lymph node (LN) stage were independent prognostic factors for adenoid cystic carcinoma (ACC) of the sublingual gland; while age, pathological LN stage, and distant metastasis were prognostic factors for patients with non-ACC of the sublingual gland. Patients with higher clinical stage were more likely to undergo tumor recurrence.

CONCLUSIONS

Malignant sublingual gland tumors are rare, and neck dissection should be performed in male MSLGT patients with higher clinical stage. Among patients with both ACC and non-ACC MSLGT patients, pN+ indicate a poor prognosis.

Risk Factors for Locoregional Recurrence and Distant Metastasis in 143 Patients with Adenoid Cystic Carcinoma of the External Auditory Canal

AIMS

Adenoid cystic carcinoma (ACC) grows slowly and is characterised by potential recurrence and metastasis to distant organs. This study aimed to evaluate the risk factors for locoregional recurrence (LRR) and distant metastasis in patients with ACC of the external auditory canal (EAC).

MATERIALS AND METHODS

Demographic, pathological, therapeutic and survival data of 143 patients with EAC ACC were reviewed in this study. Univariate and multivariate Cox proportional hazard regression analyses were carried out to determine the risk factors for LRR and distant metastasis. Factors associated with overall survival after LRR and distant metastasis were also analysed.

RESULTS

During a median follow-up of 49 months, 31 of 143 patients were observed with LRR and 34 developed distant metastasis. Bone invasion and histological subtype were independent risk factors for locoregional recurrence-free survival. T stage and LRR were independent risk factors for distant metastasis-free survival. Salvage surgery and adjuvant radiotherapy or chemoradiotherapy for LRR resulted in better survival, whereas extrapulmonary metastasis and LRR were associated with a higher risk of poor survival after distant metastasis.

CONCLUSION

Patients with distant metastases, especially those with LRR, are at significant risk of poor prognosis. Our findings emphasise the importance of long-term regular follow-up and recommend surgical intervention with radiotherapy for recurrent EAC ACC.

A torus-like sublingual adenoid cystic carcinoma in a 35-year-old male: Review of literature and case report

Key Clinical Message

The case report describes an adenoid cystic carcinoma occurring at a rare location and the diagnostic pathway. Swellings of the floor of the mouth, whether painful or without subjective symptoms and regardless of consistency, should be taken seriously.

Abstract

Adenoid cystic carcinoma (ADCC) of the sublingual salivary gland only accounts for 2% of all ADCCs. In this study, we report a rare case of ADCC with sublingual salivary gland origin in a 35-year-old man and a comprehensive review of articles published over the past 62 years.

Approaches to the Management of Metastatic Adenoid Cystic Carcinoma

High rates of recurrence and distant metastasis are a foremost challenge in the management of adenoid cystic carcinoma (ACC), occurring in approximately 40% of all ACC patients. Despite the morbidity and mortality resulting from recurrent/metastatic (R/M) disease, there are no FDA-approved systemic agents for these patients. In this review, we summarize pertinent ACC pathophysiology and its implications for different systemic treatment regimens in R/M ACC. We review the evidence for the most widely used systemic agents - cytotoxic chemotherapy and tyrosine kinase inhibitors (TKIs) targeting VEGFR - in addition to immune checkpoint inhibitors and non-TKI biologic agents. Exciting emerging targets for R/M ACC, including inhibitors of Notch signaling, stemness, PRMT5, and Axl, are also discussed. Lastly, we review local therapies for small-volume lung disease in patients with oligometastatic ACC, specifically pulmonary metastasectomy and stereotactic body radiation therapy (SBRT). Future development of targeted molecular agents which exploit the underlying biology of this disease may yield novel therapeutic options to improve clinical outcomes in patients with R/M ACC.

Development and Characterization of MYB-NFIB Fusion Expression in Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) is the second most common cancer type arising from the salivary gland. The frequent occurrence of chromosome t(6;9) translocation leading to the fusion of MYB and NFIB transcription factor genes is considered a genetic hallmark of ACC. This inter-chromosomal rearrangement may encode multiple variants of functional MYB-NFIB fusion in ACC. However, the lack of an ACC model that harbors the t(6;9) translocation has limited studies on defining the potential function and implication of chimeric MYB-NFIB protein in ACC. This report aims to establish a MYB-NFIB fusion protein expressing system in ACC cells for in vitro and in vivo studies. RNA-seq data from MYB-NFIB translocation positive ACC patients' tumors and MYB-NFIB fusion transcript in ACC patient-derived xenografts (ACCX) was analyzed to identify MYB breakpoints and their frequency of occurrence. Based on the MYB breakpoint identified, variants of MYB-NFIB fusion expression system were developed in a MYB-NFIB deficient ACC cell lines. Analysis confirmed MYB-NFIB fusion protein expression in ACC cells and ACCXs. Furthermore, recombinant MYB-NFIB fusion displayed sustained protein stability and impacted transcriptional activities of interferon-associated genes set as compared to a wild type MYB. In vivo tumor formation analysis indicated the capacity of MYB-NFIB fusion cells to grow as implanted tumors, although there were no fusion-mediated growth advantages. This expression system may be useful not only in studies to determine the functional aspects of MYB-NFIB fusion but also in evaluating effective drug response in vitro and in vivo settings.