The Utility of MYB Immunohistochemistry (IHC) in Fine Needle Aspiration (FNA) Diagnosis of Adenoid Cystic Carcinoma (AdCC)

Proceedings of the 2024 North American Society of Head and Neck Pathology Companion Meeting, Baltimore, MD, March 24, 2024: Navigating Ancillary Studies in Basaloid/Blue Salivary Tumors

BACKGROUND

Basaloid salivary tumors can demonstrate significant morphologic overlap and be challenging to diagnose.

METHODS

A review of select ancillary studies in basaloid salivary tumors was performed.

RESULTS

A number of immunohistochemical stains, including PLAG1, HMGA2, β-catenin, MYB, and RAS Q61R, have been more recently incorporated into the diagnostic workup of basaloid salivary tumors.

CONCLUSIONS

Although reported variability in their performance has perhaps limited their widespread adoption, these immunohistochemical studies can nevertheless be useful in supporting pathologic diagnoses, particularly when considered in more specific differentials or when used as a panel with other markers.

S, Kripesh G. A Study on Myloblastosis Gene (MYB) in Adenoid Cystic Carcinoma Using the New IHC Marker MYB (SZ04-81)

Background and aim: Adenoid cystic carcinoma is one of the most common malignant neoplasms of the salivary gland. It has overlapping histological features with other salivary gland tumors. MYB is a nuclear marker which is known to be expressed in Adenoid cystic carcinoma. In this study we aim to determine the sensitivity and specificity of MYB IHC marker to differentiate Adenoid cystic carcinoma from other benign and malignant salivary gland tumors. Materials and method: This is a retrospective case control study on the paraffin blocks of 78 cases of salivary gland tumors obtained over a period of 5 years. MYB Ser11 monoclonal antibody of clone SZ04-81 IHC, a nuclear marker was done on all cases. The results observed was tabulated and statistical analysis was done to calculate the sensitivity and specificity of the MYB IHC marker. Results: The mean age group of Adenoid cystic carcinoma was 45 years with a female preponderance. 60% of the cases of Adenoid cystic carcinoma were from minor salivary glands spread across various sites. The sensitivity and specificity of the MYB IHC marker were statistically analyzed and found to be 93.9% and 97.8% respectively. Conclusion: The present study shows substantial expression of MYB immunohistochemical marker in Adenoid cystic carcinoma, with a very high sensitivity and specificity obtained using the clone SZ04-81. Thus this marker can be used in the diagnosis of adenoid cystic carcinoma. However, correlation with H & E and FISH studies are required.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03471-4.

Salivary glands adenoid cystic carcinoma: a molecular profile update and potential implications

Adenoid cystic carcinoma (ACC) is an aggressive tumor with a high propensity for distant metastasis and perineural invasion. This tumor is more commonly found in regions of the head and neck, mainly the salivary glands. In general, the primary treatment modality for ACC is surgical resection and, in some cases, postoperative radiotherapy. However, no effective systemic treatment is available for patients with advanced disease. Furthermore, this tumor type is characterized by recurrent molecular alterations, especially rearrangements involving the MYB, MYBL1, and NFIB genes. In addition, they also reported copy number alterations (CNAs) that impact genes. One of them is C-KIT, mutations that affect signaling pathways such as NOTCH, PI3KCA, and PTEN, as well as alterations in chromatin remodeling genes. The identification of new molecular targets enables the development of specific therapies. Despite ongoing investigations into immunotherapy, tyrosine kinase inhibitors, and anti-angiogenics, no systemic therapy is approved by the FDA for ACC. In this review, we report the genetic and cytogenetic findings on head and neck ACC, highlighting possible targets for therapeutic interventions.

Bronchial cytology of pulmonary adenoid cystic carcinoma - A multi-institute series with emphasis on immunocytochemistry

BACKGROUND

Pulmonary adenoid cystic carcinoma (AdCC) is a central and superficial primary lung neoplasm, well-suited for sampling by bronchial cytology. This study aims to review the cytologic features of pulmonary AdCC on bronchial cytology, and to report an experience of applying immunocytochemistry on this rare entity.

METHODS

A multi-institute review of bronchial cytology specimens from histologically proven pulmonary AdCCs was performed. Published cases of bronchial cytology of pulmonary AdCC were reviewed. The cytologic features and immunocytochemical profile for pulmonary AdCC was summarized and compared with pertinent differentials.

RESULTS

A total of 16 specimens from eight patients were retrieved. The initial cytologic diagnoses were negative (n = 7), atypia (n = 6), suspicious (n = 2) and AdCC (n = 1). Retrospective review showed eight bronchial cytology specimens (including five cases of atypia) with tumor cells present. The tumor cells displayed small basaloid nuclei with occasional small nucleoli, mild nuclear atypia, and scanty cytoplasm. Architectural patterns observed included clusters, tubules, solid sheets, three-dimensional balls, papillary-like fronds, and complex cribriform structures. Basement-membrane-like material, free or associated with tumor cells, were seen in all cases. Immunocytochemistry was performed in one specimen. MYB was positive. TTF-1, synaptophysin and chromogranin were negative. Epithelial and basal markers demonstrated a dual cell population. Literature review yielded 28 cases. Cytologic features described were similar except for cytoplasmic vacuolation in one case.

CONCLUSION

Basement membrane-like material is specific for AdCC. MYB positivity, TTF-1 and neuroendocrine marker negativity, support a diagnosis of AdCC. Other immunocytochemistry and cytologic features overlap significantly with adenocarcinoma and small cell carcinoma of lung.

Analysis of Cytological Misdiagnosis and Oversight of Adenoid Cystic Carcinoma of Salivary Gland

OBJECTIVE

In this article on adenoid cystic carcinoma (ACC) of salivary gland, we intend to summarize the causes of misdiagnosis and oversight of ACC hoping to improve cytological diagnostic accuracy, clinical management and patient treatment.

METHODS

The study retrospectively reviewed 32 patients with ACC of salivary gland, registered at the Affiliated Hospital of Southwest Medical University from July 2014 to June 2021. These cases were diagnosed by FNA and surgical excision biopsy. All cytopathological results were retrospectively categorized according to Milan system for reporting salivary gland cytopathology (MSRSGC). The accuracy of FNA was verified by surgical excision biopsy.

RESULTS

Of these 32 patients, 16 (50.0%) cases were male, and 16 (50.0%) were female. Their age ranged from 21 to 79 years, with an average age of 50.32 years. The highest incidence (15/32, 46.9%) of ACC was observed in patients between 41 and 50 years of age. 10 cases (31.3%) occurred in the parotid gland, 9 cases (28.1%) in the submandibular gland, 9 cases (28.1%) in the sublingual gland, 3 cases (9.4%) in the palate, and 1 case (3.1%) in the lip. Among the 32 cases of ACC, 23 cases (71.9%) were classified to VI, 4 cases (12.5%) to IVa, and 5 cases (15.6%) to II by MSRSGC. A comparison of the FNA results with biopsy showed that the accuracy of FNA in ACC of salivary gland is 71.9%. Being able to identify the cytomorphological features is the key factor for accurate diagnosis of ACC of the salivary gland.

CONCLUSION

Our results confirm that FNA is an important initial screening in the diagnosis of ACC of salivary gland. Increased study of the cytomorphology of ACC is beneficial for more accurate diagnosis of ACC, to reduce misdiagnosis and oversight.

Fine-Needle Aspiration Cytology for Parotid Tumors

Fine-needle aspiration (FNA) cytology is widely used in clinical practice as a simple and minimally invasive test for parotid tumors that allows for preoperative estimation of benignancy and malignancy, histological type, and malignancy grade and can be performed on an outpatient basis. In recent years, cell blocks prepared with core needle biopsy (CNB) and liquid-based cytology (LBC) have increased the reliability of immunostaining and molecular biological testing, leading to improved diagnostic accuracy. In 2018, the Milan System for Reporting Salivary Gland Cytology was introduced, but it does not include malignancy grade or histological type, so we proposed the Osaka Medical College classification as a more clinically based cell classification that includes both types of information, and we have reported on its usefulness. This review gives an overview of the history and use of FNA and describes CNB and LBC and the two classification systems.

Molecular testing of cytology specimens: overview of assay selection with focus on lung, salivary gland, and thyroid testing

Ancillary and molecular testing of cytopathology specimens has emerged as a reliable and useful tool to provide diagnostic information and treatment-related biomarker status for the management of cancer patients. The cytology specimens obtained through minimally invasive means have proven suitable testing substrates for a variety of ancillary tests, including immunohistochemistry, fluorescence in situ hybridization, as well as polymerase chain reaction and next generation sequencing molecular techniques. By focusing specifically on the cytology specimen, this review provides an overview of basic testing considerations and assay selection in addition to updates on the ancillary testing of cytologic tumor specimens from the lung, salivary gland, and thyroid.

The use of diagnostic patterns for interventional cytopathology during rapid on-site evaluation and final classification

Pathologist-performed fine-needle aspiration, or interventional cytopathology, is a minimally invasive, highly accurate technique for sampling and diagnosing palpable lesions. Utilizing cytomorphologic patterns during rapid onsite evaluation (ROSE) and final classification is one of many strategies that an interventional cytopathologist can employ to simplify the diagnostic approach. Herein, we provide an overview of the salient cytomorphologic patterns encountered in common specimens obtained by the interventional cytopathologist, including major salivary glands, the thyroid gland, and superficial lymph nodes. The topics covered should provide a primer for those interested in utilizing a site-specific, pattern-based approach to cytopathologic evaluation. In summary, cytomorphologic patterns can be used during ROSE to establish adequacy, build a differential diagnosis, and to appropriately triage the specimen for additional investigation, such as microbiology cultures, a liquid-based preparation, a cell block preparation, flow cytometry, chemical analysis, or molecular diagnostic tests. Finally, this approach can be applied at the time of diagnosis to suggest additional ancillary studies, such as immunohistochemistry, and to inform accurate and definitive classification.