Basal cell adenoma: A diagnostic dilemma on fine needle aspiration cytology

Preoperative cytopathological investigatory aids in the diagnosis of salivary gland lesions

Salivary gland lesions are a group of heterogeneous lesions inclusive of non-neoplastic and neoplastic lesions. History, clinical examination and preoperative investigations attempt to minimise the challenges faced in diagnosing these diverse lesions. Preoperative investigations include imaging and cytopathology. The advent of onsite evaluation methods to ensure sample adequacy and newer reporting systems that assign risk of malignancy has improved the sensitivity and specificity of cytopathology. The scope of this review is limited to the preoperative cytopathological investigations and the diagnostic challenges met in reporting salivary gland tumours.

Diagnostic Accuracy of Fine Needle Aspiration Cytology (FNAC) in Salivary Gland Lesions with Histopathological Examination (HPE) Correlation in a Tertiary Care Centre in Southern India

This study aimed to determine the diagnostic yield of fine-needle aspiration cytology (FNAC) in salivary gland lesions compared to histopathological diagnosis. The present study was done on patients above 18 years of age, with a palpable swelling, who are clinically diagnosed as salivary gland lesions were evaluated. A total of 31 patients were evaluated in this study. The mean age of the patients was 41 years ± 16.08. The male to female ratio of patients evaluated in our study was 1: 1.066, with a marginal preponderance in the female population. There was a higher incidence of carcinoma in females than males. Parotid gland lesions comprised 83.9% of all the salivary gland lesions analyzed, while submandibular gland lesions comprised 16.1%. In our study, the distribution between non-neoplastic, neoplastic benign, and neoplastic malignant lesions was 9.6%, 83.8%, and 6.4%. The overall diagnostic accuracy for non-neoplastic and neoplastic lesions is 90.3%, with a sensitivity of 89% and a specificity of 100%. The segregation of the results into the positive and negative class of diagnostic outcomes shows 80.6% for true positive, 9.7% for true negative, 0% for false-positive, and 9.7% for false-negative reports. Diagnostic accuracy in differentiating non-neoplastic and neoplastic lesions is 90.3%, with a sensitivity and specificity of 89.0% and 100%, respectively. The diagnostic accuracy of FNAC in differentiating benign from malignant lesions in our study is 93.5% (29 out of 31), the sensitivity of FNAC in our study for diagnosing malignancy is poor, and the specificity is 100%. It can be concluded that FNAC is more accurate in diagnosing benign lesions and more specific than sensitive in diagnosing malignant lesions.

Application of the Milan System for Reporting Salivary Gland Cytopathology: A Retrospective 12-Year Bi-institutional Study

OBJECTIVES

Multi-institutional studies are required for the validation of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC).

METHODS

A total of 1,560 fine-needle aspirations of the salivary glands were retrieved from two institutions for a 12-year period. The diagnoses were reclassified based on the MSRSGC. Risk of malignancy (ROM) for each category was calculated based on 694 histologic follow-up cases.

RESULTS

The ROM for each category was: 18.3% for nondiagnostic, 8.9% for nonneoplastic, 37.5% for atypia of undetermined significance (AUS), 2.9% for benign neoplasm, 40.7% for salivary gland neoplasm of uncertain malignant potential (SUMP), 100% for suspicious for malignancy, and 98.3% for malignant. The sensitivity, specificity, positive predictive rate, and negative predictive rates were 89%, 99%, 98%, and 96%, respectively.

CONCLUSIONS

The results of the current study are in keeping with the MSRSGC. The indeterminate categories of AUS and SUMP showed intermediate ROMs at 37.5% and 40.7%, respectively.

Cytological features of basal cell adenoma of salivary glands: Analysis of 19 cases emphasizing stromal spindle cells

BACKGROUND

Basal cell adenoma (BCA) of the salivary gland is a relatively rare benign tumor. Although the presence of stromal spindle cells is a characteristic histopathological feature, this finding has not been the focus of much attention in the cytodiagnosis of BCA. Thus, we analyzed the cytological features of BCA, especially the presence of stromal spindle cells.

METHODS

Patients who were histopathologically diagnosed with BCA and underwent preoperative fine-needle aspiration cytological examination were enrolled in this study. The cytological characteristics including arrangement and shape of the neoplastic cells, nuclear and cytoplasmic features, and the presence of stromal spindle cells were reviewed.

RESULTS

Nineteen patients were enrolled in the study. The cytological specimens were cellular and composed of small or large clusters or both. The neoplastic cells had scant cytoplasm and small round to oval nuclei. Basement membrane-like material was observed in 57.9%, and peripheral palisading was noted in 84.2%. Loose aggregates of stromal spindle cells were present in 63.2%, and the stromal spindle cells shown in the histological examination of 85.7% of cases were expressed in the cytological specimens.

CONCLUSION

This study clearly demonstrated the relatively high frequency of stromal spindle cells in cytological specimens of BCA. This finding is characteristic of BCA, and therefore, the combination of cytological features, including packed clusters of neoplastic cells with scant cytoplasm and small nuclei, peripheral palisading, and basement membrane-like material, and the presence of stromal spindle cells could increase the diagnostic success of BCA.

Fine Needle Aspiration Cytology of Basal Cell Adenoma of Parotid Simulating Adenoid Cystic Carcinoma

Basal cell adenoma is a rare type of monomorphic salivary adenoma most commonly involving the parotid gland. Cytology of basal cell adenoma closely mimics many other benign and malignant basaloid neoplasms. Cytological features of membranous basal cell adenoma simulate adenoid cystic carcinoma in fine needle aspiration cytology (FNAC) smears. Here, we are presenting a rare case of cytodiagnosis of membranous basal cell adenoma of parotid gland in an elderly lady, which mimicked adenoid cystic carcinoma on FNAC. We discuss the cytomorphology of this rare case with an emphasis on cytological difference between membranous basal cell carcinoma and adenoid cystic carcinoma as well as other basaloid neoplasms.

Synchronous Ipsilateral Parotid Tumors with Cytologic-Histologic Correlation

Synchronous ipsilateral tumor formation within a major salivary gland is a very rare event. In this case, a 54-year-old female tobacco smoker presented with a slowly enlarging left parotid gland. Computed tomography of the neck demonstrated a solid mass superficial to a cystic mass in the deep lobe of the gland. Ultrasound-guided fine needle aspiration yielded oncocytic cells, lymphoid cells, and granular debris along with rare cohesive groups of basaloid cells. Parotidectomy was performed, and the resected gland was found to contain two adjacent but distinct masses. One mass, a predominantly solid, well-circumscribed lesion composed of ribbons of double-layered oncocytic cells and a lymphoid stroma with germinal center formation, was a Warthin tumor. The other mass, a predominantly cystic lesion composed of cords and nests of basaloid cells with associated deposits of basement membrane-like material, was a basal cell adenoma of the membranous type. To our knowledge, this is the first reported case of synchronous Warthin tumor and basal cell adenoma of the parotid gland with cytologic-histologic correlation attributable to each tumor.

Basal cell adenoma of the parotid gland: Cytological diagnosis of an uncommon tumor

Basal cell adenoma (BCA) is a rare benign epithelial tumor of the salivary gland, displaying monomorphic basaloid cells without a myxochondroid component, representing 1-3% of all salivary gland neoplasms seen predominantly in women over 50 years of age. It is uncommon in young adults. Cytodiagnosis of basaloid tumors chiefly basal cell adenoma of the salivary gland, is extremely challenging. The cytological differential diagnoses range from benign to malignant, neoplastic to non- neoplastic lesions. Histopathological examination is a must for definitive diagnosis, as these entities differ in prognosis and therapeutic aspects. We present a 22-years-old male with this uncommon diagnosis with a discussion on the role of cytological diagnosis. Fine needle aspiration cytology is a simple, minimally invasive method for the preoperative diagnosis of various types of neoplastic and non-neoplastic lesions. The knowledge of its pitfalls and limitations contributes to a more effective approach to treatment.

MYB Gene Abnormalities t(6;9) in Adenoid Cystic Carcinoma Fine-Needle Aspiration Biopsy Using Fluorescence In Situ Hybridization

Context.—Fine-needle aspiration (FNA) biopsy of salivary gland neoplasms can have a variety of overlapping appearances. Basaloid neoplasms can be a diagnostic challenge, and FNA cytomorphology alone cannot always provide a definitive diagnosis.

Objective.—To examine the incidence and potential utility of detecting a MYB translocation by fluorescence in situ hybridization (FISH) in adenoid cystic carcinomas (AdCCs) and pleomorphic adenoma FNA smears with known surgical outcomes.

Design.—Patients who underwent FNA biopsy for surgically confirmed AdCCs and pleomorphic adenomas were identified. Fluorescence in situ hybridization, using commercially available fluorescent-labeled probes, hybridizing to MYB-telomeric and MYB-centromeric, was used to identify the MYB gene and to evaluate it for abnormalities and translocation. Using a fluorescent microscope, 4′,6-diamidino-2-phenylindole (DAPI)-stained, nonoverlapping cells were counted, and 10% or greater abnormal cells were considered positive.

Results.—The 10 AdCC and 13 pleomorphic adenoma FNA cases had FISH evaluations performed; 50% (5 of 10) of the AdCC cases showed a MYB abnormality by FISH; 40% (4 of 10) AdCCs showed a positive break-apart signal in most cells (48%–84%). One case (10%) of AdCC showed a trisomy MYB signal pattern without the break-apart translocation pattern. Of the 13 pleomorphic adenomas, none (0%) of the cases showed a MYB translocation or abnormality by FISH. MYB FISH abnormalities showed a 100% positive predictive value, 50% sensitivity, and 100% specificity, when differentiating AdCC from pleomorphic adenoma.

Conclusions.— MYB gene abnormalities were present in 50% (5 of 10) of the AdCC cases. This corresponds to the reported prevalence in formalin-fixed, paraffin-embedded tissue for AdCC surgical resections. Using FISH testing for detecting MYB gene abnormalities in the salivary gland of FNA biopsies has the potential to provide additional, helpful ancillary information in diagnosing AdCC.

Metastatic basal cell carcinoma of the posterior neck: case report and review of the literature

Although primary basal cell carcinoma (BCC) represents an extremely common malignancy, metastases derived from BCC are exceedingly rare. The prognosis for metastatic BCC is poor, and little consensus exists regarding predictive factors or optimal treatment strategies. Here, we present the case of a 63-year-old man with BCC of the neck who subsequently developed multiple metastases to subcutaneous tissue, lymph nodes, and the parotid gland. Risk factors and clinical features of metastatic BCC are reviewed, as is the relationship of histopathologic subtype to metastatic behavior. Current chemotherapeutic and targeted therapies also are discussed in the context of recent advances in molecular biology.