Adenoid Cystic Carcinoma of the Oral Cavity: Radiology-Pathology Correlation

Adenoid cystic carcinoma of head and neck: Summary and review of imaging findings

Purpose

Current reports of adenoid cystic carcinoma of the head and neck (ACC) are all case reports, and there is no basilar summary of its imaging findings. This study aims to summarise ACC's computed tomography (CT) and magnetic resonance imaging (MRI) findings to improve radiologists' knowledge of this disease.

Methods

We collected clinical and imaging data of patients with ACC during the last decade, and two radiologists retrospectively analysed the imaging characteristics.

Results

Of the 16 patients included, six were able to self-perceive bulkiness, and 11 had regional pain. Tumour morphology was regular in six cases, with clear borders in 11 cases, invasion of the surrounding bony mass in 12 cases, and invasion of peripheral nerves in 15 cases. CT mostly shows an irregular soft-tissue density mass with mild-to-moderate enhancement after contrast medium administration. On MRI, the ACC showed isointense or hypointense signals on T1-weighted images (T1WI) and hyperintense or slightly hyperintense signals on T2-weighted images (T2WI). All signals were markedly enhanced after gadolinium enhancement.

Conclusions

ACC often has an irregular morphology, sometimes with a cystic component, enhancement on enhancement scans, easy destruction of adjacent bone, and invasion of peripheral nerves. The diagnosis should be considered when these features are encountered in clinical practice.

Comparison of 68Ga-PSMA-HBED-CC and 18F-FDG PET/CT in the Evaluation of Adenoid Cystic Carcinoma-A Prospective Study

PURPOSE OF STUDY

18F-FDG PET/CT plays a major role in diagnosis and staging of head and neck cancer; however, FDG has lower uptake in adenoid cystic carcinoma (AdCC). Prostate-specific membrane antigen (PSMA) expression is found to be associated with endothelial cells or tumor neovasculature in malignant AdCC and salivary duct carcinoma. Thus, present study is aimed to compare the role of 68Ga-PSMA and 18F-FDG PET/CT in patients with primary and/or metastatic AdCC.

MATERIALS AND METHODS

Histopathologically proven AdCC patients were intravenously injected with 370 MBq (10 mCi) of 18F-FDG and 111-185 MBq (3-5 mCi) of 68Ga-PSMA. Images were acquired at 60 and 45 minutes postinjection for 18F-FDG and 68Ga-PSMA, respectively, on dedicated PET/CT scanners. Visual and semiquantitative analyses of PSMA expression in regional and metastatic sites were performed by 2 experienced nuclear medicine physicians.

RESULTS

Seventeen patients (7 men, 10 women) having mean age of 44 ± 14.19 years were prospectively included in the study. Of 17 patients, FDG PET/CT was performed in only 14 (82%) patients. PSMA and FDG uptakes were seen at the primary site in 16 (94%) and 13 (93%) patients, respectively, whereas 1 patient was postradical tumor excision. Lung lesions (n = 7) and lymph nodes (n = 5) were detected on both FDG and PSMA PET scans. However, cerebellar and meningeal metastasis (n = 1, 6%) and bony lesions (n = 2, 12%) were detected only on PSMA PET/CT but not visualized on FDG PET/CT scan.

CONCLUSIONS

PSMA may have theranostic importance in unresectable or metastatic AdCC, besides having a role in staging/restaging.

Immunohistochemical Study of Cancer Stem Cell marker, Tight Junction Protein, and Lymphatic Density in Malignant Salivary Gland Tumors

Background: CD117/c-kit, is a powerful stem cell marker for malignant salivary gland tumors in which dysregulation of c-kit is closely associated with impairment of cell adhesion molecules and cancer metastasis. Objective: The main purpose of this work is to evaluate the immunohistochemical expression of c-kit, and claudin-1 and measure the density of lymph vessels (LVD) in common malignant salivary gland tumors by using podoplanin (D2-40) antibody. Materials and Methods: Immunohistochemical staining with streptavidin peroxidase was used to analysis the expression of c-kit, claudin-1 and stained podoplanin (D2-40) lymphatic vessels on fifty archival paraffin blocks of malignant salivary gland tumor (MSGTs) cases included 20 cases of AdCC, 11 cases of MEC, 10 cases of CXPA,              6 cases of AcCC, and 3 cases of PAC. Results: The immunopositivity of c-kit (CD117) was detected in 44/50 (88%) of studied cases, whereas, claudin-1 protein was observed in 35 (70%) of our specimens of MSGTs.  Count down of stained lymph vessels between examined cases was, MEC on the top, followed by CXPA, AdCC, PAC and AcCC. A direct correlation was observed between c-kit and lymphatic density, on the other hand, the inverse correlation was found d between c-kit and cld-1, as well as, between cld-1 and lymphatic density Conclusion: Up regulation of cancer stem cell marker c-kit (CD117) expression is associated with decrease of tight junction protein cld-1 and increase the density of stained lymphatic vessels by podoplanin (D2-40) antibody which confirms the using of c-kit inhibitor to improve treatment strategy of malignant salivary gland tumors.

Second Malignancies after Radiation Therapy: Update on Pathogenesis and Cross-sectional Imaging Findings

A wide spectrum of second cancers occur as late complications of radiation therapy (RT) used to treat various malignancies. In addition to the type and dose of radiation, lifestyle, environmental, and genetic factors are important to the development of second malignancies in cancer survivors. Typically, RT-induced malignancies (RTIMs) are biologically aggressive cancers with a variable period of 5-10 years for hematologic malignancies and 10-60 years for solid tumors between RT and the development of the second cancer. Although carcinomas and leukemias commonly develop after low-dose RT, sarcomas occur in tissues or organs that receive high-dose RT. Angiosarcomas and unclassified pleomorphic sarcomas are the two most common RT-associated sarcomas; other sarcomas include malignant peripheral nerve sheath tumors, leiomyosarcomas, osteosarcomas, chondrosarcomas, and dedifferentiated or pleomorphic liposarcomas. Select RTIMs show tumor genetic characteristics that allow accurate diagnosis. Nearly all cutaneous angiosarcomas after RT for breast cancer and 90% of RT-associated malignant peripheral nerve sheath tumors are characterized by MYC gene amplifications and loss of H3 K27me3 expression, respectively. Classic papillary thyroid carcinomas that develop after RT frequently harbor RET/PTC rearrangements and have a favorable prognosis, despite their advanced stage at patient presentation. Select RTIMs demonstrate characteristic imaging findings and typically develop in the prior radiation field. Imaging is essential to early diagnosis, characterization, localization, and staging of RTIMs. Familiarity of radiologists with the diverse spectrum of RTIMs is essential for early diagnosis and optimal management. An invited commentary by Shapiro is available online. ^©RSNA, 2021.

Primary Intraosseous Adenoid Cystic Carcinoma with Widespread Skeletal Metastases Showing Features of High-Grade Transformation

Malignant salivary gland carcinomas arising primarily within the jaw bones are extremely rare. The most common salivary malignancy in these locations is mucoepidermoid carcinoma followed by adenoid cystic carcinoma and adenocarcinoma. The clinical picture and imaging studies of these malignancies may be confused with odontogenic lesions which are more common in this location. Adenoid cystic carcinomas have a prolonged clinical course, tendency for perineural invasion and distant metastasis and multiple recurrences. The diagnosis of these tumors requires thorough histopathologic examination. Immunohistochemical studies may be required in cases showing solid growth pattern. High-grade transformation, earlier termed as dedifferentiation, has been observed in several salivary gland carcinomas including adenoid cystic carcinoma. These transformed tumors are reported to have an extremely poor prognosis. Here, we report a case of primary intraosseous adenoid cystic carcinoma with extensive skeletal metastases which showed a negative staining with p63 and positive staining with CD117. The tumor had a predominant solid growth pattern with areas indicative of high-grade transformation. A negative p63 staining may indicate an incomplete or focal loss of abluminal layer and this is one of the criteria for high-grade transformation in adenoid cystic carcinoma.

The current markers of cancer stem cell in oral cancers

Head and neck cancer (HNC) constitute 5% of all reported cancers. Among all, the oral cavity cancer is the most frequent type of HNC which accounts for over half of HNC cases. Mouth cancer ranks the sixth leading cause of cancer-related mortality. Generally, conventional chemotherapy has shown success at decreasing relapse and metastasis rates and improves the overall prognosis. Recently, target therapy and targeted drug delivery systems have been introduced as promising treatments. The elimination of efficiency of current therapeutic strategies due to the spared cancer stem cells that cause chemotherapy resistance, relapse and metastasis. Inefficiency methodologies in the elimination of all cancer cells in the body are a major problem that remained to be resolved before to confront the new cancer therapies. Many studies imply to cancer stem cell markers as important agents for targeted anti-cancer as well as improving chemotherapy efficiencies. The potentials of targeted cancer therapy led us to search for novel markers in the mouth cancer stem cells especially in rare cancers. The aimed of this research was, first a comprehensive critical review of the previous studies on the markers of cancer stem cells in oral cancers including oral squamous cell carcinoma, salivary gland cancers, and to highlight the most common cancer stem cell markers which have potential to be exploited as indicators for the preneoplastic lesion malignancy, oral cancer progression, and/or treatment prognosis.

Multiphase contrast-enhanced computed tomography imaging features of salivary duct carcinoma: differentiation from other salivary gland malignancies

OBJECTIVE

The aim of this study was to investigate the imaging features of salivary duct carcinoma (SDC) with multiphase contrast-enhanced computed tomography (CECT) and to compare them with those of mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ACC), and acinic cell carcinoma.

STUDY DESIGN

A total of 63 patients with histologically diagnosed salivary gland malignancies underwent preoperative multiphase CECT. Clinical information, location, size, mass pattern, enhancement pattern, borders, invasion of adjacent tissues, and lymph node metastasis were evaluated. Computed tomography (CT) number attenuation patterns were calculated.

RESULTS

SDCs were significantly more common in males and in the parotid gland (P ≤ .018). They were more likely to invade into adjacent tissues and metastasize to lymph nodes (P ≤ .032). Six SDCs (66.7%) had comedonecrosis, as detected on histopathologic examination, and 3 lesions presented cribriform necrosis on CECT. CT numbers during delayed-phase scanning were significantly higher in SDC than in ACC (P = .031). Significant differences were discovered between MEC and ACC for CT numbers during arterial-phase scanning (P = .047) and in the ratio of CT numbers (P = .018).

CONCLUSIONS

SDC exhibits some specific CT features, and multiphase CECT imaging is useful in the differential diagnosis of salivary gland malignancies.

Computed tomographic features of adenoid cystic carcinoma in the palate

Background

To evaluate the computed tomographic features and create a prediction model for clinical diagnosis of adenoid cystic carcinoma (ACC) in the palate with intact mucosa.

Methods

From March 2016 to May 2018, 102 patients with palatal tumors and intact mucosa, including 28 patients with a pathological diagnosis of ACC after surgery, were enrolled in this study. The patients’ clinical symptoms, computed tomographic features and pathological diagnoses were recorded and analyzed. Independent predictors of ACC were determined by using univariate analysis and multivariate logistic regression, and the discrimination and calibration of the prediction model was evaluated, and internal validation was performed.

Results

Univariate analysis of patients showed that ACC patients were more likely than non-ACC patients to be older (P = 0.019); to have palatine bone destruction (P<0.001) and greater palatine foramen (GPF) enlargement (P<0.001); to have involvement of the pterygopalatine fossa (P<0.001), foramen rotundum (P<0.001), nasal cavity (P<0.001) and maxillary bone (P<0.001); and to have numbness (P = 0.007) and pain (P<0.001). Multivariate logistic analysis showed that age and GPF enlargement were independent predictors of ACC in palatal tumors. The diagnostic prediction model showed good discrimination and calibration, as evaluated by the area under the receiver operating characteristic curve (0.98) and the Hosmer-Lemeshow goodness-of-fit test (P = 0.927).

Conclusions

The palate ACC prediction model based on age and GPF enlargement shows excellent discrimination with no evidence of poor calibration. Older patients with palatal tumors and intact mucosa should be considered for ACC when they have GPF enlargement.

Electronic supplementary material

The online version of this article (10.1186/s40644-019-0190-z) contains supplementary material, which is available to authorized users.

Oropharyngeal adenoid cystic carcinoma invading the mandibular bone through the mandibular foramen

Adenoid cystic carcinoma (ACC) is a rare epithelial tumor of the head and neck region, and one of the most common malignant tumors of the salivary glands. ACC is a slow-growing tumor characterized by perineural invasion and often has a high-recurrence rate. We describe a case of oropharyngeal ACC invading the mandibular bone through the mandibular foramen that showed a rare pattern of origin and invasion. A 70-year-old woman complained of noise and pain around the right temporomandibular joint. Osteomyelitis was suspected on the initial imaging examinations, although the findings were slightly atypical. However, a mass was observed in the right oropharyngeal wall on subsequent imaging examinations, and mandibular bone invasion, rather than osteomyelitis, was additionally suspected. The mass in the right oropharyngeal wall and right mandible was surgically excised. On postoperative histopathological examination, the mass was finally diagnosed as ACC. As tumor cells were also observed around the inferior alveolar nerve, mandibular bone invasion through the mandibular foramen was suspected. An oropharyngeal ACC invading the mandibular bone through the mandibular foramen is extremely rare. The present case suggests that bone invasion should be considered carefully with several imaging examinations when a malignant tumor such as ACC is observed around the jaw bone.

Educational Impact of Trainee-Facilitated Head and Neck Radiology-Pathology Correlation Conferences

The goal of this study was to evaluate the benefits of resident and fellow-facilitated radiology-pathology head and neck conferences. A total of seven resident-facilitated and six fellow-facilitated head and neck radiology-pathology cases were presented as part of the radiology department conference series. The radiology residents were surveyed regarding the perceived quality and effectiveness of the fellow-facilitated sessions. The number of publications yielded from all the cases presented was tracked. Overall, the residents assessed the quality of the fellow-facilitated conferences with an average score of 3.9 out of 5 and the overall helpfulness with an average of 3.5 out of 5. The overall average level of resident understanding among the residents for the topics presented to them by the fellows at baseline was 2.5 out of 5 and 3.4 out of 5 after the presentations, which was a significant increase (p-value < 0.01). There were three peer-reviewed publications generated from the resident presentations and four peer-reviewed publications generated from the fellow presentations, which represents a 54% publication rate collectively. Therefore, trainee-facilitated head and neck radiology-pathology conferences at our institution provide added learning and scholarly activity opportunities.