Acinic cell carcinoma of the salivary glands: A literature review

Rare Presentation of Acinic Cell Carcinoma in the Parotid Gland

Acinic cell carcinoma (ACC) arising in the salivary glands is a rare tumor. It is a low-grade malignant salivary gland tumor. It is predominantly seen in females and occurs in the fifth and sixth decades of life. It is mostly located in the parotid gland. ACC has a significant potential for recurrence and metastasis. Therefore, long-term follow-up is necessary after treatment. Here, a 28-year-old male presented with right preauricular swelling for 9 months. Ultrasound of the head-and-neck region and fine-needle aspiration cytology of preauricular swelling suggest the diagnosis of neoplasm in the parotid gland, most probably a benign tumor. After that, a total parotidectomy with facial nerve preservation was performed. On histopathological and immunohistochemical study was consistent with the diagnosis of ACC in the parotid gland.

Successful endotracheal intervention for primary tracheal acinic cell carcinoma: A case report and literature review

INTRODUCTION

Primary tracheal acinic cell carcinoma (ACC) is an exceptionally rare malignancy, posing challenges in understanding its clinical behavior and optimal management. Surgical resection has traditionally been the primary treatment modality, but we present a compelling case of tracheal ACC managed with endotracheal intervention, challenging conventional approaches.

PATIENT CONCERNS

A 53-year-old woman presented with shortness of breath, cough, and hemoptysis. Enhanced computed tomography revealed an obstructive tracheal lesion, leading to her referral for further assessment.

DIAGNOSIS

Microscopic evaluation, immunohistochemistry, and clinical assessments confirmed primary tracheal ACC, an exceedingly rare condition with limited clinical insights.

INTERVENTIONS

We utilized rigid bronchoscopy to perform endotracheal intervention, successfully resecting the tumor and restoring tracheal patency. Postoperatively, the patient received no radiotherapy or chemotherapy.

OUTCOMES

The patient achieved complete recovery, with 24-month follow-up examinations indicating no recurrence or metastatic disease. Only minimal scar tissue remained at the resection site.

CONCLUSION

This case demonstrates the potential of endotracheal intervention as a curative approach for primary tracheal ACC, minimizing invasiveness and preserving tracheal function. Collaborative research efforts and extensive case reporting are crucial for advancing our understanding of this rare malignancy and optimizing treatment strategies for improved patient outcomes.

Analysis of B7-H4 Expression Across Salivary Gland Carcinomas Reveals Adenoid Cystic Carcinoma-Specific Prognostic Relevance

B7-H4 (VTCN1), a member of the B7 family, is overexpressed in several types of cancer. Here we investigated the pattern of expression of B7-H4 in salivary gland carcinomas (SGC) and assessed its potential as a prognostic marker and therapeutic target. Immunohistochemistry (IHC) analyses were performed in a cohort of 340 patient tumors, composed of 124 adenoid cystic carcinomas (ACC), 107 salivary duct carcinomas (SDC), 64 acinic cell carcinomas, 36 mucoepidermoid carcinomas (MEC), 9 secretory carcinomas (SC), as well as 20 normal salivary glands (controls). B7-H4 expression was scored and categorized into negative (<5% expression of any intensity), low (5%-70% expression of any intensity or >70% with weak intensity), or high (>70% moderate or strong diffuse intensity). The associations between B7-H4 expression and clinicopathologic characteristics, as well as overall survival, were assessed. Among all tumors, B7-H4 expression was more prevalent in ACC (94%) compared with those of SC (67%), MEC (44%), SDC (32%), and acinic cell carcinomas (0%). Normal salivary gland tissue did not express B7-H4. High expression of B7-H4 was found exclusively in ACC (27%), SDC (11%), and MEC (8%). In SDC, B7-H4 expression was associated with female gender (P = .002) and lack of androgen receptor expression (P = .012). In ACC, B7-H4 expression was significantly associated with solid histology (P < .0001) and minor salivary gland primary (P = .02). High B7-H4 expression was associated with a poorer prognosis in ACC, regardless of clinical stage and histologic subtype. B7-H4 expression was not prognostic in the non-ACC SGC evaluated. Our comparative study revealed distinct patterns of B7-H4 expression according to SGC histology, which has potential therapeutic implications. B7-H4 expression was particularly high in solid ACC and was an independent prognostic marker in this disease but not in the other SGC assessed.

Chaotic transformation of parotid acinic cell carcinoma to metastatic dedifferentiated high-grade pathology - A rare case with clinical and emotional challenge

INTRODUCTION AND IMPORTANCE

Acinic cell carcinoma (AciCC) is a rare entity in which high-grade transformation (HGT), formerly dedifferentiation, is uncommon. This case report presents a rare case of AciCC, with rapid transformation to metastatic high-grade dedifferentiated pathology after initial curative treatment.

CASE PRESENTATION

A 58-year-old woman presented in the medical oncology clinic with a progressive swelling on the right side of her face. Magnetic resonance imaging revealed a 5 × 5 cm lobulated parotid gland lesion, and fine needle aspiration biopsy was consistent with carcinoma. After informed consent, a Modified-Blair incision was given as a standard approach to the right preauricular area under general anaesthesia, and a right superficial parotidectomy with the removal of the tumor and selective lymph node dissection was performed. Histopathology of the resected mass was reported as parotid AciCC. She was given adjuvant radiation therapy. A repeat PET CT scan ten weeks after the completion of her adjuvant radiation treatment showed local disease recurrence as well as multiple pulmonary deposits. A repeat biopsy was reported as DOG-1 positive dedifferentiated (high-grade) acinic cell carcinoma, and she was offered platinum-based palliative systemic chemotherapy.

CLINICAL DISCUSSION

Parotid acinic cell carcinomas with high-grade transformation are rare. This case highlights its critical diagnostic markers, curative and palliative management and long-term follow-up.

CONCLUSION

The transformation of parotid AciCC to high-grade, dedifferentiated pathology is unusual and belligerent. Hence, these tumors need intense treatment with a multimodality approach. Close follow-ups with history and physical examination, along with periodic imaging, should be considered for these patients.

Role of Adjuvant Radiotherapy in Acinic Cell Carcinoma of the Salivary Glands: A Systematic Review

A systematic review was carried out to evaluate if adjuvant radiotherapy for acinic cell carcinomas (ACCs) of salivary glands improves survival. Twelve retrospective studies published between 2000 and 2020 that analysed the effect of radiotherapy on salivary gland neoplasms and ACCs of salivary glands and met the inclusion criteria were included in the review. The overall quality of the studies was moderate to low. There was no high-quality evidence for improved survival with radiotherapy for ACCs of the salivary gland. Some evidence suggests that there may be an advantage for patients with high-grade tumours, but these data should be interpreted with caution due to the small number of patients and low-quality evidence. Good quality of evidence is lacking. Recommendation for adjuvant radiotherapy for tumours with poor prognostic factors will require discussion and shared decision-making with the patients.

Amide proton transfer-weighted magnetic resonance imaging for the differentiation of parotid gland tumors

Purpose

To assess the usefulness of amide proton transfer-weighted (APTw) imaging in the differentiation of parotid gland tumors.

Materials and methods

Patients with parotid gland tumors who underwent APTw imaging were retrospectively enrolled and divided into groups according to pathology. Two radiologists evaluated the APTw image quality independently, and APTw images with quality score ≥3 were enrolled. The maximum and average values of APTw imaging for tumor lesions (APTmax and APTmean) were measured. The differences in APTmax and APTmean were compared between malignant tumors (MTs) and benign tumors (BTs), as well as between MTs and pleomorphic adenomas (PAs) and between MTs and Warthin tumors (WTs). Independent-samples t-test, Kruskal-Wallis H test, and receiver operating characteristic (ROC) curve analyses were used for statistical analysis.

Results

Seventy-three patients were included for image quality evaluation. In this study, 32/73 and 29/73 parotid tumors were scored as 4 and 3, respectively. After excluding lesions with quality score ≤2 (12/73), the APTmean and APTmax of MTs were 4.15% ± 1.33% and 7.43% ± 1.61%, higher than those of BTs 2.74% ± 1.04% and 5.25% ± 1.54%, respectively (p < 0.05). The areas under the ROC curve (AUCs) of the APTmean and APTmax for differentiation between MTs and BTs were 0.819 and 0.821, respectively. MTs indicated significantly higher APTmean and APTmax values than those of PAs (p < 0.05) and WTs (p < 0.05). The AUCs of the APTmean and APTmax for differentiation between MTs and PAs were 0.830 and 0.815 and between MTs and WTs were 0.847 and 0.920, respectively.

Conclusion

Most APTw images for parotid tumors had acceptable image quality for APTw value evaluation. Both APTmax and APTmean can be used to differentiate MTs from BTs and to differentiate MTs from subtype parotid gland tumors.

Recurrent acinic cell carcinoma of the parotid gland with lateral skull base invasion: Case report and discussion of the literature

Medical records of a 76-year-old woman with a recurrent acinic cell carcinoma of the left parotid gland with lateral skull base invasion were reviewed. She underwent subtotal petrosectomy followed by radiation therapy. After surgery, she remained disease-free for more than 16 months.

Acinic cell carcinoma of parotid gland

Acinic cell carcinoma (ACC) is a rare malignant tumor of the salivary glands that accounts for 6%-10% of all salivary gland malignancies. It has a propensity to considerably recur, metastasize to the lung or cervical lymph nodes. In addition, ACC can potentially be fatal. The parotid gland is where ACC most frequently begins. The purpose of this paper was to describe an unusual case of parotid gland ACC in a 58-year-old Vietnamese adult female. Before surgery, a fine-needle aspiration biopsy revealed the existence of tumor cells with acinar differentiation. Following that, she underwent successful surgery without complications. The existence of ACC was verified by the postoperative final histologic results.

Acinic cell carcinoma of the oral and maxillofacial region: an international multicenter study

The aim of this study was to describe the prevalence, clinicopathological, and prognostic features of acinic cell carcinoma (AciCC) of the oral and maxillofacial region. AciCC cases were retrospectively retrieved from 11 pathology centers of three different countries. Medical records were examined to extract demographic, clinical, pathologic, and follow-up information. A total of 75 cases were included. Females (65.33%) with a mean age of 45.51 years were mostly affected. The lesions usually presented as an asymptomatic (64.28%) nodule (95.66%) in the parotid gland (70.68%). The association of two histopathological patterns was the most common finding (48.93%) and the tumors presented mainly conventional histopathological grades (86.11%). Surgical treatment was performed in the majority of the cases (59.19%). Local recurrence was observed in 20% of the informed cases, regional metastasis in 30.43%, and distant metastasis in 12.50%. The statistical analysis showed that the cases with a solid histopathological pattern (p=0.01), high-grade transformation (p=0.008), recurrence (p=0.007), and regional metastasis (p=0.03) were associated with poor survival. In conclusion, high histopathological transformation, presence of nodal metastasis, and recurrence were prognostic factors for AciCC of the oral and maxillofacial region.

Survival outcomes, prognostic factors, and effect of adjuvant radiotherapy and prophylactic neck dissection in salivary acinic cell carcinoma: A prospective multicenter REFCOR study of 187 patients

BACKGROUND

Acinic cell carcinomas (AciCCs) are malignant tumours of the salivary glands. The aim of this work was to analyse data from the national REFCOR multicenter cohort (i) to investigate the prognostic factors influencing survival outcomes in AciCC, (ii) to assess the impact on survival of postoperative radiotherapy (RT) in patients treated for AciCC without high-grade transformation and (iii) to explore the prognostic impact of prophylactic neck dissection (ND) in patients treated for AciCC of the major salivary glands.

PATIENTS AND METHODS

Data from all the patients treated for salivary AciCC between 2009 and 2020 were extracted from the REFCOR database. Survival outcomes and prognostic factors influencing Disease-Free Survival (DFS) and Overall Survival (OS) were investigated using univariate and multivariate analyses. Propensity score matching was used to assess the impact of postoperative RT and prophylactic ND on DFS.

RESULTS

A total of 187 patients were included. After a median follow-up of 53 months, their 5-year OS and DFS rates were 92.8% and 76.2%, respectively. In multivariate analysis, male sex, older age, higher T and N status, and high grade were independently associated with a worse DFS. In the subpopulation analysed after propensity score matching, patients with cN0 AciCC without high-grade transformation who were treated by surgery and RT did not have an improved DFS compared to patients who were treated by surgery alone (hazard ratio (HR) = 0.87, p = 0.8). Factors associated with nodal invasion were T3-T4 status and intermediate/high histological grade. After propensity score matching, prophylactic ND was associated with a trend toward a better DFS (HR = 0.46, p = 0.16).

CONCLUSIONS

These results suggest that (i) long-term follow-up (>5 years) should be considered in patients with AciCC, (ii) treatment by surgery alone could be an option in selected cN0 patients with AciCC without high-grade transformation and (iii) prophylactic ND may be considered preferentially in patients with T3-T4 status and/or intermediate/high histological grade.

Does three-dimensional intraglandular location predict malignancy in parotid tumors?

Tumors arising within the parotid encompass a heterogeneous mix of benign and malignant neoplasms and other tissue growths. The purpose of this study was to determine the association between the location of intraparotid masses and the risk of malignancy. A retrospective cohort study was performed of patients diagnosed with parotid tumors following open tumor excision. The primary predictor variable was the location of the epicenter of the tumor in three-dimensional space, as determined from preoperative imaging. Other variables were patient demographics and clinical parameters. The primary outcome variable was the final histopathologic diagnosis of a benign or malignant process. A χ² analysis was performed to test for any significant associations between demographic, clinical, and radiographic factors in relation to the outcome, and backwards stepwise logistic regression analysis was used to control for variables. Both increasing age (P = 0.002) and the presence of local pain (P = 0.020) were associated with malignancy. Tumors located anterior to the posterior border of the retromandibular vein had 2.18 times higher odds of malignancy (95% confidence interval 1.13-4.21; P = 0.020). Multivariate regression analysis suggested that patient age, the presence of pain, and tumor location anterosuperiorly and superoinferiorly could all assist in determining the odds of malignancy.

Prognostic Assessment and Risk Stratification in Patients With Postoperative Major Salivary Acinar Cell Carcinoma

OBJECTIVE

To investigate the clinicopathological features and prognosis of postoperative major salivary acinar cell carcinoma (MSACC) and develop a prognostic model.

STUDY DESIGN

Retrospective cohort analysis of a public database.

SETTING

Patients with MSACC were identified from the Surveillance, Epidemiology, and End Results database (1975-2019).

METHODS

Overall survival (OS) was evaluated using Kaplan-Meier curves and a log-rank test. Univariate and multivariate Cox analyses were performed to explore independent prognostic factors. The prognostic model was constructed using screened variables and further visualized with a nomogram and web calculator, and assessed by concordance index, the area under the curve, calibration curve, and decision-making curve analysis.

RESULTS

An upward trend in the incidence of MSACC was observed throughout the study period. A total of 1398 patients were enrolled (training cohort: 978; validation cohort: 420), and the 5- and 10-year OS rates were 97.7% and 81.6%, respectively. Age, marital status, sex, histological grade, T stage, and lymph node status were identified as prognostic factors for OS. A novel nomogram was developed and showed excellent discrimination and clinical applicability. Additionally, a web calculator was designed to dynamically predict patient survival. Based on the nomogram-based score, a risk stratification system was constructed to distinguish patients with different risks. The OS of high-risk patients was significantly lower than that of the low-risk subgroup.

CONCLUSION

Long-term survival in postoperative MSACC was influenced by 6 prognostic factors. The proposed model enables individualized survival prediction and risk stratification, prompting us to be vigilant in high-risk subgroups and consider timely adjustment of subsequent treatment.

Solitary Scalp Metastases of Parotid Pleomorphic Adenoma: A Case Report

Pleomorphic adenoma (PA) of the parotid gland is considered one of the commonest benign salivary gland neoplasms in both adults and pediatrics. However, metastatic pleomorphic adenoma (MPA) is extremely rare. In the past three decades, multiple cases were reported in the literature of MPA, where the metastatic phase has been preceded by a local recurrence for the majority of the cases. Metastases to the lungs, liver, bone, head and neck were reported. This paper will discuss a rare case presentation of MPA that metastasised solely to the face and scalp subcutaneous tissue with no other sites of metastases in a male adult.

Ectopic Cushing's Syndrome Secondary to Acinic Cell Carcinoma of the Parotid Gland: A Case Report

We present a case report of a patient with a rare high-grade transformation of an acinic cell carcinoma (ACC) of the parotid gland, who developed Cushing's syndrome (CS) as a result of ectopic secretion of adrenocorticotropic hormone by the tumour. The hypercortisolism was successfully treated with metyrapone, and the ACC was treated with local radiotherapy and a combined six cycles of gemcitabine and cisplatin, having achieved a partial response to the tumour. A multidisciplinary approach and combined medical treatment with radiotherapy and were essential for disease control and CS management. ACC should be considered in the differential diagnosis of ectopic CS.

The Therapeutic Landscape of Salivary Gland Malignancies-Where Are We Now?

Salivary gland malignancies (SGMs) account for less than 5% of new diagnoses in head and neck tumors. If feasible, surgery is the preferred treatment modality. Nevertheless, some malignancies have a tendency of recurrence, with possible distant metastasis. Alternative treatment strategies, such as primary radiation or chemotherapeutics, often present low response rates. As a result, there is an unmet need for novel therapeutic approaches. Nowadays, target-based therapies (e.g., small inhibitors and immunotherapy) are used by the medical oncologist for possible treatment of advanced SGMs. Based on recent published trials, some novel treatments may provide additional disease control for some patients. However, sample sizes are small, the general findings are unsatisfactory, and a lot of uncertainties remain to be elucidated. Nevertheless, research shows that patients do not benefit from blind administration of systemic treatments and therefore a more personalized approach is highly needed. The aim of this review paper is to summarize the most recent advances in the biological understanding and molecular pathways of salivary gland cancers, the association of these pathways with the current treatments used and their implications for more personalized targeted-based therapies.

MicroRNAs’ Crucial Role in Salivary Gland Cancers’ Onset and Prognosis

Simple Summary

Salivary gland cancers are incredibly heterogeneous, both in the physical onset and in the aggressiveness. Setting up a novel diagnostic and prognostic detection method based on the noninvasive microRNAs’ profiling might represent a goal for the clinical management of those particular malignancies, saving precious time for the patients.

Abstract

Salivary gland cancer (SGC) is an uncommon and heterogeneous disease that accounts for around 8.5% of all head and neck cancers. MicroRNAs (miRNAs) consist of a class of highly conserved, short, single-stranded segments (18–25 nucleotides) of noncoding RNA that represent key gene-transcription regulators in physiological and pathological human conditions. However, their role in SGC development and progression is not completely clear. This review aims to compile and summarize the recent findings on the topic, focusing on the prognostic and diagnostic value of the major modulated and validated microRNAs in SGC. Their differential expression could possibly aid the clinician in delivering an early diagnosis, therapeutic strategy and precision medicine.

An Exquisite Case Report of Follicular Variant of Acinic Cell Carcinoma of the Parotid Gland With Review of Literature

Acinic cell carcinoma (ACC), previously called acinic cell tumor, is an uncommon malignant neoplasm that tends to recur locally without proper treatment measures. This low-grade neoplasm has four histological subtypes. We hereby report a case of a follicular variant of ACC, which is a rare subtype. A 20-year literature search encompassing this variant of ACC of the parotid region was also performed, which showed four reported cases. A 60-year-old woman reported to our college, Kalinga Institute of Dental Sciences, with the chief complaint of pain and swelling in her upper right back tooth region for the past three months. Upon incisional biopsy, histopathological examination revealed a follicular variant of ACC. Further, immunohistochemistry was also performed using markers such as DOG-1, CK7, S-100, and thyroglobulin, which showed CK7 marker positivity. Subtotal parotidectomy was performed and the tissue was sent for histopathological analysis. Although ACCs are slow-growing and indolent in character, they can frequently recur locally decades later and spread to distant organs. Long-term follow-up is necessary following therapy as ACC has a noticeably high propensity to relapse and create latent metastases.

DOG1 as an Immunohistochemical Marker of Acinic Cell Carcinoma: A Systematic Review and Meta-Analysis

DOG1 is a transmembrane protein originally discovered on gastrointestinal stromal tumors and works as a calcium-activated chloride channel protein. There are a limited number of articles on the potential utility of this antibody in the diagnosis of salivary gland tumors in routine practice. In this study, we aimed to investigate the role of DOG1 as an immunohistochemical marker in patients with salivary acinic cell carcinoma (ACC) through meta-analysis. A literature search was performed of the PubMed, Scopus, and Web of Science databases for English-language studies published from January 2010 to September 2021. The literature search revealed 148 articles, of which 20 were included in the study. The overall rate of DOG1 expression in salivary acinic cell carcinoma was 55% (95% CI = 0.43–0.58). Although ACC is a challenging diagnosis, paying careful attention to the cytomorphological features in conjunction with DOG1 immunostaining can help to reach an accurate diagnosis.

NR4A3 Fluorescence In Situ Hybridization Analysis in Cytologic and Surgical Specimens of acinic cell carcinoma

BACKGROUND

Acinic cell carcinoma (AciCC) may pose a diagnostic challenge, particularly on small biopsies and fine needle aspiration (FNA) because of its variable histology including potential high grade transformation and its mimickers. Immunoreactivity with circumferential membranous staining for DOG1 can support the diagnosis of AciCC but is not entirely specific. A novel rearrangement t(4;9)(q13;q31) leading to upregulation of nuclear receptor subfamily 4 group A member 3 (NR4A3) has been described in AciCC, is potentially detectable by Fluorescence in situ hybridization (FISH) and may be useful in the evaluation for AciCC.

METHODS

Using NR4A3 Dual Color Break Apart Probe (Zytovision, Germany) FISH was performed on AciCCs from three large academic institutions. NR4A3 rearrangement was defined as positive signal patterns in 15% of tissue interphase nuclei.

RESULTS

52 AciCCs including 47 resections and 5 FNAs (including 5 paired FNA/resections) were analyzed. 5 non-AciCC salivary gland tumors and 2 sialadenitis cases were used as controls. 8 (15%) (8/52) AciCCs failed FISH testing. FISH was positive in 23 AciCCs (sensitivity 59%, 23/39) with 100% concordance between five matched resection/FNAs (three were positive for FISH and two were negative). FISH was negative in all non-AciCCs (specificity: 100%, 0/7).

CONCLUSION

NR4A3 FISH has a sensitivity of 59% and specificity of 100% in detecting AciCC which suggests that NR4A3 rearrangement-driven upregulation is a recurrent, specific oncogenic event in AciCC, consistent with prior results. 100% concordance between matched FNA/resection samples validate its potential utility on cytology samples.

The Youngest Case of Metachronous Bilateral Acinic Cell Carcinoma of the Parotid Gland: A Case Report and Literature Review

Introduction

Acinic cell carcinoma (ACC) is a low-grade malignant salivary neoplasm that represents 17% of all salivary gland malignancies. It has a tendency to affect young individuals, especially females. ACC mainly originates in the parotid gland and has a potential for recurrence and metastases. Rarely, ACC can affect both parotid glands in a single individual. A bilateral ACC of the parotid gland could either present as a synchronous or a metachronous tumor. Case Report. Our patient is a 19-year-old female known case of ACC of the right parotid gland. The tumor was resected in December 2017. After 3 years, she presented with a left parotid pain and swelling, which raised the suspicion of a contralateral metachronous tumor of the left parotid gland. In September 30, 2020 we proceeded with ultrasound-guided fine needle aspiration of the left intraparotid lesion, and the results turned out to be consistent with ACC. Here, we report a case of a 19-year-old female presenting with metachronous bilateral ACC of the parotid gland with an interval of 3 years, which is the 6^th of its kind in the literature and the youngest amongst them.

Conclusion

Despite the rareness of metachronous occurrence of bilateral ACC of the parotid gland, it is still encountered in the medical practice. Here, we are highlighting the importance of follow-up with a periodic clinical and radiological examinations, bearing in mind the contralateral nonaffected parotid gland.

Spinal metastasis of parotid acinic cell carcinoma followed by intradural extramedullary recurrence: illustrative case

BACKGROUND

The diagnosis and management of acinic cell carcinoma (ACC) is often challenging given its similarity to benign tumors, high incidences of late recurrence and distant metastasis, and tendency to be resistant to systemic chemotherapy. A primary parotid ACC resulting in an intradural extramedullary mass has not been reported.

OBSERVATIONS

The authors describe such a case that presented as a progressive cervical myelopathy 29 years after initial diagnosis. The tumor, located at the C2–C3 level, infiltrated the dura and contained both extradural and intradural components. This occurred 18 months after the incomplete resection of an extradural metastasis at the same location.

LESSONS

Although intracranial and extradural metastases of various primary malignancies are well reported, secondary spinal intradural malignancies are rare. As a result, there are no established guidelines for the surgical management of intradural extramedullary metastases and prognosis may be difficult to establish. In this case, treatment options were limited because systemic therapy options had been exhausted and repeated radiation to the area was not recommended. We report on this case to highlight the clinical course of a rare local recurrence after spinal metastasis leading to an intradural extramedullary tumor and to show that surgical intervention can lead to improvement of neurological symptoms.

MR Imaging of Salivary Gland Tumors

Neoplasms of the salivary glands are characterized by their marked histologic diversity giving them nonspecific imaging findings. MR imaging is the best imaging modality to evaluate salivary gland tumors. Multiparametric MR imaging combines conventional imaging features, diffusion-weighted imaging, and perfusion imaging to help distinguish benign and low-grade neoplasms from malignant tumors; however, a biopsy is often needed to establish a definitive histopathologic diagnosis. An awareness of potential imaging pitfalls is important to prevent mistakes in salivary neoplasm imaging.

Rapid Response to the Combination of Lenvatinib and Sintilimab in a Pancreatic Acinar Cell Carcinoma Patient With Elevated Alpha-Fetoprotein: A Case Report

A 48-year old woman was diagnosed with metastatic pancreatic acinar cell carcinoma (PACC) and with a marked elevation in alpha-fetoprotein (AFP), this being a recognized but uncommon feature of PACC. As she refused chemotherapy, the combined therapy of lenvatinib and sintilimab (lenvatinib 8 mg, orally, qd; and sintilimab 100 mg, intravenous glucose tolerance test, q21d) was given, which conferred significant tumor shrinkage and long progression-free survival (>21 months). This study is the first report and description of a PACC demonstrating favorable response to the combination therapy of an antiangiogenic agent and immunotherapy.

Acinic cell carcinoma of the parotid gland with neuroendocrine differentiation

Acinic cell carcinoma (ACC) is a malignant salivary gland tumor characterized by tumor cells displaying acinar features. Usually presenting as a slow-growing tumor, ACC, however, may show dedifferentiation to a higher grade including neuroendocrine carcinoma. In addition, ACC may rarely show focal neuroendocrine differentiation without any frank evidence of neuroendocrine carcinoma. We describe such a case of ACC of the parotid gland in a 65-year-old female, which showed neuroendocrine differentiation. The diagnostic clues, immunohistochemistry panel, and prognostic and treatment aspects are also presented.

Patterns of care analysis for salivary gland cancer: a survey within the German Society of Radiation Oncology (DEGRO) and recommendations for daily practice

Background

Salivary gland cancer (SGC) is rare and a heterogeneous type of cancer. Prospective randomized trials are lacking. No guideline focusing on standard procedures of radiotherapy (RT) in the treatment of SGC exists. Therefore, we surveyed the members of the German Society of Radiation Oncology (DEGRO) to gain information about current therapeutic strategies of SGC.

Methods

An anonymous questionnaire was designed and made available on the online platform umfrageonline.com. The corresponding link was sent to all DEGRO members who provided their user data for contact purposes. Alternatively, a PDF printout version was sent. Frequency distributions of responses for each question were calculated. The data were also analyzed by type of institution.

Results

Sixty-seven responses were received, including answers from 21 university departments, 22 non-university institutions, and 24 radiation oncology practices. Six participants reported that their departments (practice: n = 5, non-university hospital: n = 1) did not treat SGC, and therefore the questionnaire was not completed. Concerning radiation techniques, target volume definition, and concomitant chemotherapy, treatment strategies varied greatly among the participants. Comparing university vs. non-university institutions, university hospitals treat significantly more patients with SGC per year and initiated more molecular pathological diagnostics.

Conclusion

SGC represents a major challenge for clinicians, as reflected by the inhomogeneous survey results regarding diagnostics, RT approaches, and systemic therapy. Future prospective, multicenter clinical trials are warranted to improve and homogenize treatment of SGC and to individualize treatment according to histologic subtypes and risk factors.

Supplementary Information

The online version of this article (10.1007/s00066-021-01833-x) contains supplementary material, which is available to authorized users.

Ectopic ACTH Secretion Secondary to Metastatic Acinic Cell Carcinoma of the Parotid Gland: A Case Report and Review of Current Evidence for Systemic Therapy

Acinic cell carcinoma is a rare, typically indolent, neoplasm that arises in the salivary glands. Metastatic disease is uncommon, occurring in around 10% of cases. We report the case of a 46-year-old male in whom the first sign of disseminated disease was increased skin pigmentation due to paraneoplastic Cushing’s syndrome. He underwent 3 cycles of chemotherapy with carboplatin and paclitaxel with no symptomatic improvement and a mixed response on imaging. There is no evidence that systemic therapy prolongs survival in metastatic acinic cell carcinoma, and we lack a consensus as to which treatment options are most beneficial. A summary of published evidence regarding choice of palliative chemotherapy regimens and response is discussed in relation to the case.

Differential diagnosis and treatment of salivary secretory carcinoma and acinic cell carcinoma

Secretory carcinoma (SC) and acinic cell carcinoma (AciCC) are two rare tumors originating in the salivary gland of the head and neck. Before the World Health Organization (WHO) classified SC as a new entity in 2017, the majority of SC cases were incorrectly diagnosed as AciCC. Indeed, they are similar in biological behaviors, clinical manifestations and histomorphological features. Especially, SC and zymogen granule-poor AciCC are difficult to differentiate, which brings a tough challenge in clinical diagnosis. This article provides an updated understanding of the differential diagnosis in SC and AciCC from two main perspectives: histopathology and molecular genetics. The targeted therapies for both tumors are also mentioned. It aims to give some hints in clinical diagnosis and treatment, in hopes that patients with adequate diagnosis could obtain the opportunityformore effective treatment.

Primary acinic cell carcinoma of mandible, report of a case and literature review

Introduction and importance

Acinic cell carcinoma (ACC) is a rare low-grade salivary gland malignancy that accounts for approximately 17% of all salivary gland malignancies. The most common site affected by ACC is the parotid gland followed by the submandibular glands, minor salivary glands, and sublingual glands. Also, it could hardly be observed in unusual sites such as the jaw bones.

Case presentation

This case is an example of a central acinic cell carcinoma in a 73-year-old man who came up with a painless gradual swelling for 15 months. Based on clinico-radio-pathologic findings, the diagnosis of a solid variant Intraosseous Acinic Cell Carcinoma was established. Subsequently, the patient underwent hemimandibulectomy and modified radical neck dissection, followed by postoperative radiotherapy. Within a six-month follow-up period, no evidence of residual tumor was found.

Clinical discussion

Central salivary gland carcinoma is a rare entity and intraosseous ACC is more scarcely observed. Based on our findings, a total of 17 cases of primary intraosseous ACC have been reported so far. Etiology and clinical presentations of this tumor are still vague due to its rarity.

Conclusion

Dentists and oral surgeons must be aware of such a rare malignant lesion when encountering a radiolucent lesion within the jaws. The early diagnosis and a complete surgical excision to achieve tumor-free surgical margins and a long-term follow-up could result in significantly improved survival rates.

•

ACCs are a type of uncommon salivary gland tumors and the intra-osseous counterparts are extremely rare.

•

Due to clinical and radiologic similarities to benign tumors, histopathologic and IHC findings should also be considered.

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Primary surgical design should be wide enough and en bloc resection should be suggested.

Tumour-Infiltrating Lymphocytes (TILs) and PD-L1 Expression Correlate with Lymph Node Metastasis, High-Grade Transformation and Shorter Metastasis-Free Survival in Patients with Acinic Cell Carcinoma (AciCC) of the Salivary Glands

OBJECTIVES

The aim of this study was to assess the number of tumour-infiltrating lymphocytes (TILs) and the expression of Programmed Cell Death 1 Ligand 1 (PD-L1) in Acinic Cell Carcinoma (AciCC) of the salivary glands, to enable a correlation with clinico-pathological features and to analyse their prognostic impact.

METHODS

This single centre retrospective study represents a cohort of 36 primary AciCCs with long-term clinical follow-up. Immunohistochemically defined immune cell subtypes, i.e., those expressing T-cell markers (CD3, CD4 and CD8) or a B-cell marker (CD20) were characterized on tumour tissue sections. The number of TILs was quantitatively evaluated using software for digital bioimage analysis (QuPath). PD-L1 expression on the tumour cells and on immune cells was assessed immunohistochemically employing established scoring criteria: tumour proportion score (TPS), Ventana immune cell score (IC-Score) and combined positive score (CPS).

RESULTS

Higher numbers of tumour-infiltrating T- and B-lymphocytes were significantly associated with high-grade transformation. Furthermore, higher counts of T-lymphocytes correlated with node-positive disease. There was a significant correlation between higher levels of PD-L1 expression and lymph node metastases as well as the occurrence of high-grade transformation. Moreover, PD-L1 CPS was associated with poor prognosis regarding metastasis-free survival (p = 0.049).

CONCLUSIONS

The current study is the first to demonstrate an association between PD-L1 expression and lymph node metastases as well as grading in AciCCs. In conclusion, increased immune cell infiltration of T and B cells as well as higher levels of PD-L1 expression in AciCC in association with high-grade transformation, lymph node metastasis and unfavourable prognosis suggests a relevant interaction between tumour cells and immune cell infiltrates in a subset of AciCCs, and might represent a rationale for immune checkpoint inhibition.

Clinicopathological analysis of oral and maxillofacial acinic cell carcinoma: A systematic review

BACKGROUND

The aim of the present systematic review was to analyze the available data regarding acinic cell carcinoma of the oral and maxillofacial region.

METHODS

A search strategy was performed using PubMed, Web of Science, Scopus, and Embase electronic databases.

RESULTS

Available data revealed a slight female preference (54.73%) and a mean age at diagnosis of 47.51 ± 19.85 years. The parotid glands (67.72%) were most frequently affected, and most cases were asymptomatic (69.54%). A microcystic histopathological pattern was reported in 21.56% of the cases, and the Periodic acid-Schiff was the staining method most frequently used, after the hematoxylin and eosin staining, in the tumors analyzed. The lesions were mainly treated by surgical removal (72.32%). Recurrence was reported in 81 cases (27.83%) and metastasis in 100 (42.91%). Statistical data analysis revealed that tumors located in major salivary glands and exhibiting high-grade histology were associated with local recurrence (P = .01). In addition, the patients older than 57 years, lesions with bone involvement, the high-grade tumors and the cases with a history of recurrence and metastasis were associated with a lower overall survival (P < .05).

CONCLUSION

By assembling all eligible cases in the literature, the present systematic review determined the most common clinicopathological profile of acinic cell carcinoma and the most relevant prognostic factors in a distinctly representative sample. The survey demonstrated the importance of considering the histopathological grading in order to better define the treatment for each case.

Hematological Paraneoplastic Syndrome and Heparin-Induced Thrombocytopenia in Untreated Parotid Acinic Cell Carcinoma - A Case Report

RATIONALE

Acinic cell carcinoma (ACC) is a rare and indolent malignancy commonly found in the parotid gland. This can give rise to paraneoplastic syndromes, which represent the clinical manifestations of indirect and remote events produced by tumour metabolites.

PATIENT CONCERNS

A 38-year-old Afro-Caribbean female suffered an indolent parotid mass. She only presented to our tertiary center when it started to ulcerate and bleed.

DIAGNOSIS

She was diagnosed with advanced parotid ACC. She also went on to develop an hematological paraneoplastic syndrome resulting in venous thrombi. This was complicated by her developing heparin-induced thrombocytopenia (HIT).

TREATMENT

A difficult multidisciplinary decision was made to proceed with surgery despite her extremely poor condition.

OUTCOMES

After the surgery, the patient made a full recovery.

TAKE-AWAY LESSONS

ACC is a relatively uncommon and indolent malignancy that is usually found in the parotid gland. It can be associated with a hematological paraneoplastic syndrome and further complicated by iatrogenic HIT.

Acinic cell carcinoma of the posterior buccal mucosa: A rare case report

Acinic cell carcinoma (ACC) is a low-grade malignant salivary gland neoplasm that comprises approximately 17% of primary salivary gland malignancies or about 6% of all salivary gland neoplasms. The most common intraoral sites are the buccal mucosa, lips, and palate. The diagnosis of ACC frequently presents difficulties, owing to its great radiological and cytological similarity with benign tumors and with normal acinar component of the salivary gland, respectively. The management of ACC consists of complete surgical excision. Here, we report a case of ACC on the left retromolar trigone, a rare location in a 44-year-old female.

Molecular and Cellular Modelling of Salivary Gland Tumors Open New Landscapes in Diagnosis and Treatment

Salivary gland tumors are neoplasms affecting the major and minor salivary glands of the oral cavity. Their complex pathological appearance and overlapping morphological features between subtypes, pose major challenges in the identification, classification, and staging of the tumor. Recently developed techniques of three-dimensional culture and organotypic modelling provide useful platforms for the clinical and biological characterization of these malignancies. Additionally, new advances in genetic and molecular screenings allow precise diagnosis and monitoring of tumor progression. Finally, novel therapeutic tools with increased efficiency and accuracy are emerging. In this review, we summarize the most common salivary gland neoplasms and provide an overview of the state-of-the-art tools to model, diagnose, and treat salivary gland tumors.

Clinicopathologic Features and Survival Trends for Acinic Cell Carcinoma of the Major Salivary Glands: A Surveillance, Epidemiology, and End Results Population Analysis

Background

We analyzed a population-based national registry to identify the most influential patient pretreatment and treatment factors affecting overall survival (OS) and cause-specific survival (CSS) in patients diagnosed with acinic cell carcinoma (ACC) of the major salivary glands.

Methods

Using the Surveillance, Epidemiology, and End Results (SEER) database of the US National Cancer Institute (NCI) related to survival, a total of 1,254 patients with diagnosed ACC of the major salivary glands from 1975 to 2016 met inclusion criteria. Factors significant for OS and CSS were determined using univariate and multivariate analysis with the Cox proportional hazards model.

Results

Univariate OS analysis demonstrated that surgery favorably influenced longer survival compared to no surgery (hazard ratio (HR) 2.35, P < 0.05). Patient age was found to be highly predictive of superior OS (divided into 10-year age bands, P < 0.0001, younger age better). In multivariate OS analysis, there were statistically significant worse outcomes for men (HR 1.54, P < 0.05), grades III/IV (HR 2.5, P < 0.05), and distant disease (HR 3.55, P < 0.05) or regional disease (HR 1.22, P < 0.05). Patients diagnosed during years 1996 - 2016 had better OS when compared to earlier decades 1975 - 1995 (HR 1.38, P < 0.05). In univariate analysis, the mean CSS for grades I, II, and III/IV were 429 months (95% confidence interval (CI), ± 38.39), 426 months (95% CI, ± 25.73) and 198 months (95% CI, ± 66.38). Multivariate analysis of CSS further demonstrated that there were statistically significant worse outcomes for men (HR 1.68, P < 0.05), grade III/IV (HR 3.2, P < 0.05), tumor size greater than 40 mm (P < 0.001), and distant disease (HR 4.48, P < 0.05) or regional disease (HR 1.84, P < 0.05).

Conclusions

To our knowledge, this is the largest population-based study of OS and CSS of major salivary gland ACC. We found that the patient pretreatment and treatment factors including younger age at diagnosis, female sex, early stage, lower grade, surgical excision, and recent year of diagnosis are associated with improved survival in patients diagnosed with ACC of the major salivary glands. We hope that this information will aid in construction of further research projects that better refine optimal treatment protocol of individualized patient care.

Atypical Presentation of Mammary Analogue Secretory Carcinoma of the Lip

Mammary analogue secretory carcinoma (MASC) of the salivary gland is a rare tumor that was first described by Skalova et al in 2010, and since then, only a few hundred cases have been reported in the literature. Prior to Skalova's report, MASC was histologically misclassified as acinic cell carcinoma (ACC), pleomorphic adenoma, mucoepidermoid carcinoma, or adenocarcinoma, not otherwise specified. Mammary analogue secretory carcinoma has a low incidence rate overall, accounting for less than 0.3% of all salivary gland tumors. Histopathologic and cytogenic analysis of MASC is identical to secretory carcinoma of the breast, leading to the proposed name by Skalova. The purpose of this case presentation is to describe an atypical presentation of MASC, to compare this case with the classic description of MASC, and to contrast the various features of MASC to ACC in order to improve the accuracy of future diagnoses and help guide treatment.

Significance of Nodal Metastasis in Parotid Gland Acinar Cell Carcinoma

OBJECTIVES

To evaluate the rate of lymph node metastasis in parotid gland acinar cell carcinoma, to identified factors associated with increased risk of metastasis, and to evaluate the effect of nodal metastasis on survival.

METHODS

This is a retrospective cohort study utilizing data from a large population-based cancer database. Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) 18 database. The study cohort included patients with parotid gland acinar cell carcinoma diagnosed between 2000 and 2015.

RESULTS

The overall rate of lymph node metastasis was 6.8%. T3/T4 (OR 6.17, 95% CI, 3.03 to 13.16) disease along with High Grade (OR 15.95) disease were associated with increased risk of nodal metastasis. Non-white, non-Black race was associated with decreased risk. Age and sex were not associated with nodal metastasis. Nodal metastasis was associated with worse OS (HR 6.27, 95% CI, 3.85 to 10.20) and DSS (HR 6.96, 95% CI, 3.81 to 12.73) after adjusting for covariates.

CONCLUSION

Parotid gland acinar cell carcinoma carries a low risk of nodal metastasis. Both advanced T stage and high grade are associated with increased risk of nodal metastasis. Nodal metastasis is associated with decreased overall survival.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E1125-E1129, 2021.

Acinic cell carcinoma of the salivary gland associated with lymphoid-rich stroma. A diagnostic dilemma on cytology: Study of two cases

A lymphoid-rich stroma is a common finding in salivary gland tumors. Several reports documented this association with acinic cell carcinoma (ACC). However, cytologic studies reporting this phenomenon are rare and mainly confined to sporadic single case reports. We present the cytologic features of two cases of ACCs of the parotid gland displaying a lymphoid-rich background and discuss the cytologic differential diagnoses of this uncommon ACC variant.

Computed tomography and magnetic resonance imaging in pediatric salivary gland diseases: a guide to the differential diagnosis

Salivary gland pathologies in children are frequent, particularly viral infections, but rarely need cross-sectional imaging. However, when a mass involves the salivary spaces (primarily or as a secondary invasion from other neck spaces) it may pose problems in the differential diagnosis and in immediate management. Infrequently, systemic autoimmune diseases can also involve the salivary parenchyma in children and correctly interpreting the constellation of findings in the whole body is critical for the diagnosis. Distinguishing between cystic and solid masses is the first step for radiologists in order to narrow down the diagnosis. Location and spatial extension are the most important elements differentiating cystic masses, while signal characteristics, internal structure and local invasion help in the differential diagnosis of solid masses.

Head & neck acinar cell carcinoma: a population-based study using the seer registry

Background

To explore the clinicopathologic characteristics, treatment and prognostic factors of head and neck acinar cell carcinoma (HNACC) comprehensively.

Methods

A population-based study was conducted using data from the Surveillance, Epidemiology, and End Results database (1975–2016). Overall survival (OS) and HNACC-specific survival of patients with different clinicopathologic variables were compared using the Kaplan-Meier method and Cox multivariate regression.

Results

A total of 2624 primary HNACC cases (1052 males, 1572 females) were identified. There was a significant difference in gender distribution. Among the total cohort, 2416 cases originated from salivary glands, including 2325 parotid gland ACC cases. Regardless of confounding factors, the 10-year and 20-year disease-specific survival (DSS) was 93.6 and 90%, respectively. Surgery was favourably associated with better DSS and OS [HR = 0.13, P = 0.0092 and HR = 0.23, P = 0.0203]. Gender was the only demographic independent prognostic factor for both DSS and OS [Male vs female, HR = 3.3, P = 0.0028 for DSS; HR = 2.44, P = 0.0376 for OS]. Higher pathological grade was adversely associated with DSS and OS [Grade II, HR = 4.03, P = 0.0444; Grade III + IV, HR = 35.64, P = 0.0000 for DSS; Grade III + IV, HR = 4.49, P = 0.0000 for OS, Grade I as reference]. In addition, TNM/AJCC stage was commonly associated with prognosis.

Conclusion

Surgery was the only favourable prognostic indicator for both DSS and OS. Gender, age, pathological differentiation and TNM/AJCC stage were independent prognostic factors for survival.

Perithyroidal Salivary Gland Acinic Cell Carcinoma: Morphological and Molecular Attributes of a Unique Lesion

Rarely, salivary gland tumors such as mucoepidermoid carcinoma, mammary analogue secretory carcinoma and mucinous carcinoma arise as primary tumors from ectopic or metaplastic salivary gland tissue adjacent to or within the thyroid gland. We report for the first time a case of primary salivary acinic cell carcinoma (AcCC) adjacent to the thyroid gland in a 71-year-old female patient with Crohns disease and a previous history of malignant melanoma. Following the development of a nodule adjacent to the left thyroid lobe, a fine-needle aspiration biopsy was reported as consistent with a follicular lesion of undetermined significance (Bethesda III). A left-sided hemithyroidectomy was performed. A circumscribed lesion measuring 33 mm was noted adjacent to the thyroid and trapping parathyroid, it was composed of solid nests and glands with microcystic and follicular patterns. The tumor was negative for thyroid, parathyroid and paraganglioma markers, but positive for pan-cytokeratins, CK7, CD10, CD117, androgen receptor and HNF-beta. A metastasis of a thyroid-like renal cell carcinoma was suspected but ruled out, and the patient had no evident lesions on extensive radiology of the urogenital, pulmonary and GI tracts. Based on the morphology, a diagnosis of AcCC was suggested, and confirmed with DOG1 and PAS-diastase staining. Molecular analyses pinpointed a constitutional ASXL1 variant of uncertain significance, but no fusion events. The patient had no radiological or clinical evidence of parotid, submandibular or sublingual tumors postoperatively, and the excised lesion was therefore assumed to be a primary tumor. We here detail the morphological and immunophenotypic profile of this previously undescribed perithyroidal tumor.

Acinic cell carcinoma of the parotid gland: from pathogenesis to management: a literature review

PURPOSE

Acinic cell carcinoma (ACCs) is uncommon malignant epithelial neoplasm of the salivary glands; the most common presentation is a well-defined painless solid mass. Diagnosis of ACCs is frequently complicated, due to its similarity with benign tumors.

METHODS

A review of the literature available on ACCs was carried out. Studies were sourced from PubMed with searching of relevant headings and sub-headings and cross-referencing.

RESULTS

There are no clear characteristics of ACCs found on CT, MRI and ultrasound imaging. The management of the ACC, a rare malignancy of the parotid gland, is often difficult and controversial. Radical surgery is the best treatment option. The role of radiotherapy remains controversial: the precise indications and oncologic effects of adjuvant radiotherapy in ACC of the parotid gland are not well known. There is insufficient literature regarding the chemotherapy for metastatic ACC.

CONCLUSION

Knowledge about ACC, a rare malignancy of parotid gland, has changed over the past few decades. More clinical randomized works would be needed, both to assess the real effectiveness of radio and chemotherapy and to have an unanimous consensus about their indications.

Metastatic Acinic Cell Carcinoma to the Vagina: A First Reported Case

This is a case of a 62-year-old woman with a remote history of acinic cell carcinoma of the parotid gland, who presented with a palpable vaginal mass, anterior vaginal wall prolapse, and stress urinary incontinence. A 2 cm firm mobile mass on the anterior vaginal wall was found on clinical examination. A computed tomographic scan revealed a mass between the vaginal vault and bladder that was eventually surgically excised. The histology, supported by the immunohistochemistry, revealed metastatic acinic cell carcinoma to the vagina after 37 years of her initial diagnosis. This is the first reported case in the literature to occur in the vagina.

Are demographics associated with mucoepidermoid or acinic cell carcinoma parotid malignancies in children?

Objective

To identify possible associations between patient demographics and parotid cancer histological type in pediatric patients.

Methods

Pediatric patients (ages: birth-18.0 years) in the Surveillance, Epidemiology, and End Results (SEER) database were included from 1973 to 2014 based on a diagnosis of mucoepidermoid carcinoma or acinic cell carcinoma of the parotid gland using the ICD O-3 codes of C07.9 and 8430 or 8550. Patients were classified into the following cohorts: <14 and 14-18 years of age based on the mean age at diagnosis.

Results

Three hundred and three pediatric patients were diagnosed with mucoepidermoid carcinoma or acinic cell carcinoma of the parotid gland within the SEER 18 registries. Female pediatric patients 14-18 years of age were 7.68 times more likely to have an acinic cell carcinoma (adjusted OR: 7.68 [95% CI: 2.01-29.44]). When stratified by histological type, 58.9% of female pediatric patients ≥14 years of age had an acinic cell carcinoma as compared to 37.3% of male pediatric patients ≥14 years of age, 36.5% of female pediatric patients <14 years of age, and 34.0% of male pediatric patients <14 years of age (P = 0.01).

Conclusions

Based on this study, pediatric female patients between the ages of 14 and 18 years are the most likely cohort to have acinic cell carcinoma. The results of this study may assist providers during the work up of a pediatric patient with a suspected parotid malignancy.

Ectopic Cushing's Syndrome Unveiling a Metastatic Parotid Carcinoma

Introduction

Adrenocorticotropic hormone (ACTH) ectopic production is a rare cause of Cushing syndrome (CS). The most commonly associated tumours are small-cell lung carcinoma along with bronchial and thymic carcinoids. To date, only 5 cases have been published in the literature featuring ectopic ACTH secretion from metastatic acinic cell carcinoma (ACC) of the parotid gland. We hereby describe a very uncommon case of ectopic CS (ECS) unveiling a metastatic parotid ACC.

Case Presentation

A 46-year-old man with hypertension and dyslipidemia diagnosed 4-months before, as well as new-onset diabetes mellitus unveiled 1-month earlier, was referred to emergency department for hypokalemia. Hormonal study and dynamic biochemical tests performed indicated ECS. Imaging and cytological findings pointed toward a likely primary right parotid malignancy with liver metastases. Somatostatin receptor scintigraphy has shown an increased uptake in the parotid gland and mild expression in liver metastasis. The patient underwent right parotidectomy, and histopathologic examination confirmed ACC. Meanwhile, hypercortisolism was managed with metyrapone, ketoconazole, and lanreotide. Despite chemotherapy onset, a rapid disease progression and clinical course deterioration was observed.

Conclusion

The present report highlights a rare ECS, exposing a metastatic parotid ACC, with an aggressive and challenging clinical course, representing the first case whose diagnosis of ECS came prior to ACC.