Basal Cell Adenoma and Basal Cell Adenocarcinoma

Molecular testing in salivary gland cytopathology: A practical overview in conjunction with the Milan system

Recently, significant advances in the molecular characterization of salivary gland neoplasms have facilitated the classification and diagnosis of specific diagnostic entities. In the highly challenging diagnostic scenario of salivary malignancies, molecular testing is increasingly being adopted in routine practice to refine the cytological diagnosis of salivary lesions. Here, we reviewed the most recent evidence in the field of salivary glands molecular cytopathology.

Basal cell adenoma and basal cell adenocarcinoma of the parotid gland: clinical findings and surgical outcomes in a single-institution study

BACKGROUND

Basal cell adenoma (BCA) is a rare benign tumor within the salivary glands. Basal cell adenocarcinoma (BCAC), the malignant counterpart of BCA, is also an exceedingly rare tumor with very limited clinical studies conducted. This study aims to investigate the clinical characteristics, demographics, and surgical outcomes of patients diagnosed with BCA and BCAC within the parotid gland.

METHODS

A retrospective analysis from May 2003 to August 2023 was performed for all patients undergoing parotidectomy for masses. Retrospective data on gender, age, tumor characteristics, and outcomes were collected. Surgical approaches, including negative margin attainment, capsule removal, and histological diagnosis, were also detailed.

RESULTS

The study included 1268 patients who underwent parotidectomy, resulting in 81 cases of BCA and 7 cases of BCAC. BCA patients, with a mean age of 55.1 years, showed diverse age distribution and predominantly presented in the 50s. In BCAC cases, seven female patients exhibited a predominant location in the deep lobes. FNA revealed BCAC in three out of seven cases, and subsequent parotidectomy was performed, resulting in no observed recurrences or metastases.

CONCLUSION

This study reports the largest number of BCA cases from a single institution and provides comprehensive insights into the demographics, tumor characteristics, and clinical outcomes of both BCA and BCAC. Although further research should be conducted, based on clinical follow-up results, appropriately including the capsule in the tumor excision indicates favorable outcomes, especially when the tumor size is not large.

High-grade salivary carcinomas: A current insight on diagnostic pathology and the key to clinical decision making

High-grade carcinomas of the salivary glands are a group of several tumor entities with highly malignant histologic appearances, and have an aggressive biological behavior accompanied by poor a prognosis. In general, they require more intensive treatment than low- or intermediate-grade carcinomas. High-grade salivary carcinomas are rare and the microscopic features often overlap between different tumor types, making an appropriate diagnosis challenging in daily practice settings. However, with recent rapid advances in molecular pathology and molecular-targeted therapy in this field, there is a growing need to properly classify tumors, rather than just diagnosing the cases as "high-grade carcinomas". This leads to specific treatment strategies. In this article, we review representative high-grade salivary gland carcinomas, including salivary duct carcinoma and its histologic subtypes, high-grade mucoepidermoid carcinoma, solid-type adenoid cystic carcinoma, and high-grade transformation of low- or intermediate-grade carcinomas, and discuss their differential diagnoses and clinical implications. Other rare entities, such as neuroendocrine carcinoma, NUT carcinoma, and metastatic carcinoma, should also be considered before diagnosing high-grade carcinoma, NOS. Of these tumors, salivary duct carcinoma has received the most attention because of its strong association with androgen deprivation and anti-HER2 therapies. Other tumor-type-specific treatments include anti-TRK therapy for high-grade transformation of secretory carcinoma, but further therapeutic options are expected to be developed in the future. It should be emphasized that detailed histological evaluation with adequate sampling, in addition to the effective use of molecular ancillary tests, is of the utmost importance for a suitable diagnosis.

A Rare Case of Basal Cell Adenocarcinoma of the Right Submandibular Gland

Basal cell adenocarcinoma of the submandibular gland is an extremely rare carcinoma of the salivary gland that originates from the basal cells of the submandibular gland. Due to its rarity, there are relatively few case reports and literature on this cancer. After comprehensive clinical, imaging, and pathologic analyses, we confirmed the patient's diagnosis and documented the consultation in detail. The purpose of this article is to report the case of a patient with basal cell adenocarcinoma of the submandibular gland and to perform a review of the relevant literature to improve the understanding of this rare disease.

Basal cell adenocarcinoma of the soft palate: A closer look for an exceedingly rare salivary gland tumor

Basal cell adenocarcinoma (BCAd) is an extremely rare primary biphasic carcinoma of the salivary glands with few well-documented cases reported in the literature. Herein, we report a rare case of a 44-year-old male patient who presented an oral medicine service with an erythematous nodular lesion on the soft palate, measuring 1.5 cm in its largest diameter, with a 5-year duration. The clinical diagnosis was pleomorphic adenoma, and an excisional biopsy was performed. Histopathological analysis revealed a biphasic infiltrative tumor composed of a mixture of central ductal cells and abluminal basal cells with slight atypia arranged in solid, trabecular, tubular and cribriform growth patterns in a loose stroma. The peripheral cells show a palisading arrangement with round hyperchromatic nuclei and scanty cytoplasm. Occasional mitotic figures were seen. Few spindle-shaped cells suggestive of myoepithelial cells were present in the stroma surrounding the basaloid tumor nests. The diagnosis was BCAd. The patient was referred to a head and neck service and has been followed up for 8 months with no signs of recurrence. In conclusion, although the diagnosis of BCAd can be challenging due to its rarity and morphological overlap with other salivary gland lesions, a meticulous morphological assessment is key for accurate diagnosis, especially in cases originating from minor salivary glands. Surgical excision with a wide safety margin is the treatment of choice and long-term follow-up is recommended to monitor possible recurrences.

Basal Cell Adenoma With Atypia in the Nasal Cavity Mimicking a Malignant Tumor

Basal cell adenomas (BCA) arising from the nasal cavity or paranasal sinuses are very rare. A 64-year-old male patient was suspected of having a malignant tumor after undergoing preoperative computed tomography scans and magnetic resonance imaging. The intraoperative frozen section showed a malignant tumor; however, the final diagnosis revealed BCA with atypia, tubular pattern.

[Salivary gland tumors-an overview : Advances in molecular characterization: Part II]

The second part of the article is devoted to the molecular characteristics of epithelial-myoepithelial carcinoma, polymorphous adenocarcinoma, myoepithelial carcinoma, basal cell adenocarcinoma, and salivary duct carcinoma. In addition, the new entities mucinous adenocarcinoma, sclerosing microcystic adenocarcinoma, and microsecretory adenocarcinoma are summarized. The molecular genotype can also be very helpful in diagnosing most of these entities. In this regard, overexpression of the androgen receptor and/or human epidermal growth factor receptor 2 (HER2)/neu can support diagnosis in the appropriate histopathologic context and may serve as a potential target for therapy in salivary duct carcinoma.

Basal Cell Adenoma and Basal Cell Adenocarcinoma: a 50-year Experience From a Single Institution

BACKGROUND

Basal cell adenoma (BCA) and adenocarcinoma (BCAd) are two of the least frequent salivary gland tumors. We describe the largest series of these neoplasms, spanning over a period of 50 years (1970-2020), diagnosed and treated in a single Institution.

METHODS

Sixty-eight cases were identified. Clinical and pathological data were collected and correlated with outcome.

RESULTS

Forty-one BCA and 27 BCAd were identified. BCA cases had almost pristine prognosis, with only a relapse in a tumor inadequately excised. Ten patients with BCAd developed metastases, and 14 died from the disease. The 2-year and 5-year survival was of 76% and 42%.

CONCLUSIONS

The importance of adequate excision is reinforced in BCA, with no recurrences occurring when margins were negative. Contrary to previous reports, BCAd was not associated with a good prognosis. A better understanding of the genetics of these neoplasms may identify therapeutic options when dealing with inoperable or metastatic disease.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Familial Tumor Syndromes

The initiative of the 5th edition of the WHO classification of the Head and Neck Tumours establishing a new section dedicated to familial/heritable tumor syndromes with tumors and lesions in the head and neck region was much needed to better understand the tumours, diseases, and associated syndromes, as well as establish recommendations for monitoring and treating these patients. (WHO Classification of Tumours Editorial Board. Head and Neck tumours. Lyon (France): International Agency for Research on Cancer; 2022. https://publications.iarc.fr/ ). Within the newly established chapter on genetic tumor syndromes, we have described the main manifestations on the head and neck region in 15 syndromes. This review highlights the important findings within these syndromes, especially on the update on syndromes with tumors involving the head and neck region, as Gorlin syndrome/nevoid basal cell carcinoma syndrome associated with odontogenic keratocysts; Brooke-Spiegler syndrome/familial cylindromatosis and the associated membranous-type salivary gland basal cell adenoma, PTEN hamartoma tumor syndrome/Cowden syndrome with associated facial skin and mucosal lesions and characteristic multinodular thyroid lesions, Von Hippel Lindau syndrome and the associated middle ear endolymphatic sac tumor, as well as the fascinating genetic aspects of the diverse Head and Neck Paragangliomas. We will also discuss hyperparathyroidism-jaw tumor syndrome is characterized by parathyroid tumors in association with fibro-osseous jaw tumors, as well as head and neck desmoid tumors associated with familial adenomatous polyposis with Gardner syndrome variant familial, multicentric head and neck squamous cell carcinoma, tuberous sclerosis and neurofibromatosis type 1-associated head and neck lesions.