Intercalated duct lesion of the parotid

A Rare Case of Recurrent Carcinoma Ex Basal Cell Adenoma of the Parotid Gland

Basal cell adenoma is encountered in the salivary glands, particularly the parotid gland; however, malignant transformation is rare, and recurrence is much rarer. We report the case of a 60-year-old man who had experienced a slow-growing mass in the parotid gland, which was suspected to be pleomorphic adenoma. Radiological and cytological examination suggested an atypical lesion in the left parotid. The final diagnosis reached on the excised specimen was that of a basal cell adenocarcinoma ex adenoma with close margins. The patient presented with a recurrence after two years. Routine histopathological examination with careful examination by the pathologist is essential for proper management of such rare malignant lesions, and recurrence is a possibility. A complete excision of the tumor with tumor-free margins from the beginning is suggested.

Top Ten Differentials to Mull Over for Head and Neck Myoepithelial Neoplasms

BACKGROUND

Myoepithelial neoplasms of the salivary gland are benign or malignant neoplasms composed exclusively of neoplastic myoepithelial cells. These tumors, including the benign myoepithelioma and the malignant counterpart myoepithelial carcinoma, exhibit a wide range of cytomorphologic features and architectural patterns.

METHODS

Review.

RESULTS

Myoepithelial cells can be epithelial, plasmacytoid, clear cell, spindle cell, and/or oncocytic cell, arranging as trabeculae, solid sheets, nests, cords, and/or single cells. A stromal component is commonly but not universally present, Therefore, their differential diagnoses are quite broad, including salivary gland neoplasms especially those with a myoepithelial component, plasmacytoma, melanoma, and various mesenchymal tumors.

CONCLUSION

In this review, we summarize the characteristic histologic features, useful immunohistochemical panel, and common molecular alterations of myoepithelial tumors and their top differential diagnoses. A logical stepwise algorithmic approach and an immunohistochemical panel to include multiple myoepithelial markers are essential to establish the correct diagnosis.

Hybrid intercalated duct lesion of the parotid: A case report

BACKGROUND

Intercalated duct lesions (IDLs) are considered relatively benign and rare tumors of salivary glands, that were only described recently. Their histopathological appearance may range from ductal hyperplasia to encapsulated adenoma with hybrid patterns of both variants. It is thought that IDLs may be the precursor for malignant proliferations, therefore their correct diagnosis remains crucial for proper lesion management. It is the first reported IDL case arising from the accessory parotid gland (APG), which stands for less frequent but higher malignancy rate tumor developmental area.

CASE SUMMARY

A 24-years-old male with no accompanying diseases was referred to the hospital with a painless nodule on the right cheek. On physical examination, the stiff, immobile, and painless mass was palpable in the anterior portion of the right parotideomasseteric region, just superior to the parotid duct. Ultrasound examination demonstrated 1.5 cm × 1.0 cm hypoechogenic mass on the anterior part of the right parotid gland. Ultrasound-guided fine needle aspiration cytology, followed by liquid-based fine needle aspiration biopsy were performed. However, the results were uninformative. A contrast-enhanced magnetic resonance imaging (MRI) of the parotid was obtained, demonstrating a 1.5 cm × 1.0 cm × 0.5 cm tumor with high intensity capsule together with low intensity core in the very anterior part of right superficial lobe, situated in the APG. An MRI features were uncharacteristic to common parotid tumors, therefore surgical resection followed up. After histopathological examination, the final diagnosis of hybrid IDL was confirmed.

CONCLUSION

Fine needle aspiration biopsy might not always be diagnostic, and given the malignant potential, the surgical resection of such lesion remains the treatment of choice.

Advances in PSMA theranostics

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PSMA is an appealing target for theranostic because it is a transmembrane protein with a known substrate that is overexpessed on prostate cancer cells and internalizes upon ligand binding.

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There are a number of PSMA theranostic ligands in clinical evaluation, clinical trial, or clinically approved.

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PSMA theranostic ligands increase progression-free survival, overall survival, and pain in patients with metastatic castration resistant prostate cancer.

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A major obstacle to PSMA-targeted radioligand therapy is off-target toxicity in salivary glands.

The validation of prostate specific membrane antigen (PSMA) as a molecular target in metastatic castration-resistant prostate cancer has stimulated the development of multiple classes of theranostic ligands that specifically target PSMA. Theranostic ligands are used to image disease or selectively deliver cytotoxic radioactivity to cells expressing PSMA according to the radioisotope conjugated to the ligand. PSMA theranostics is a rapidly advancing field that is now integrating into clinical management of prostate cancer patients. In this review we summarize published research describing the biological role(s) and activity of PSMA, highlight the most clinically advanced PSMA targeting molecules and biomacromolecules, and identify next generation PSMA ligands that aim to further improve treatment efficacy. The goal of this review is to provide a comprehensive assessment of the current state-of-play and a roadmap to achieving further advances in PSMA theranostics.

Parenchymal changes of salivary glands adjacent to a variety of salivary gland disorders

A fully developed tumor is the first manifestation of a typical salivary gland neoplasm. Identification of precursor lesions and the accompanying clinical findings may improve our understanding of these tumors. The frequency of possible precursor lesions of salivary gland tumors have not been systematically investigated to date. In this study, slides of 661 cases from three pathology laboratories in Ankara, Turkey were reviewed to search for possible precursor lesions. Salivary gland parenchymal changes adjacent to a variety of salivary gland disorders such as metaplastic changes, ductal epithelial hyperplasia, adenomatoid ductal hyperplasia, adenomatoid oxyphilic hyperplasia, adenomatoid hyperplasia of the minor salivary glands, myoepithelial sialadenitis and dysplasia were screened histologically as potentially precursor lesions. Nuclear protein Ki-67 and cellular tumor antigen p53 were also analyzed immunohistochemically in selected cases. Approximately 16% of the cases in this series contained various types of pathologic hyperplasia. Only a minority of these lesions were originally reported, so most of the findings in this study were not part of the original histology reports. The majority of these parenchymal changes were seen in parotids. Adenomatoid ductal hyperplasia was the most frequent possible precursor lesion, and it was found most frequently around pleomorphic adenomas. Although the biological significance of most of the lesions described in this report still remains to be understood completely, efforts to define and detect possible preneoplastic lesions should be intensified. We believe that detection and eradication of the precursors is the best way of decreasing the overall morbidity caused by salivary gland tumors.

An Unusual Hybrid Salivary Gland Tumor: Molecular Analysis Informs the Potential Pathogenesis of This Rare Neoplasm

Background

The presence of two or more tumor entities growing in adjacent locations within the salivary gland is very rare, and pathologic studies on such lesions are limited, particularly those with molecular information. Since the clinical history and imaging studies are usually nonspecific, accurate diagnosis and clinical management largely depend on a thorough histological examination.

Methods and Results

We describe a 71-year-old man with an unusual case of hybrid salivary gland tumor composed of mucoepidermoid carcinoma and basal cell adenoma. Molecular analysis revealed differing driver genetic alterations in each component.

Conclusions

Hybrid salivary gland tumors are rare, and their pathogenesis is controversial. The combination of mucoepidermoid carcinoma and basal cell adenoma has not been previously described. While malignant transformation of adenoma to carcinoma seems plausible, gene sequencing was more suggestive of their independent derivation. Key to appropriate surgical management is identifying the more aggressive component, ideally at the time of intraoperative consultation.

Adenomatous ductal proliferation/hyperplasia in the parotid gland associated without any other pathological lesions; a report and survey of the literatures

Adenomatous ductal proliferation/hyperplasia (ADP/H) is a rare hyperplastic condition of the salivary gland. It is mostly associated with other salivary gland pathologies such as tumors and inflammations, and is incidentally found in tissue sections during histopathological examinations of those diseases. Herein, we report a case of ADP/H in the parotid gland not associated with any other pathological lesions, and present a review of the literature on this condition. A 60-year-old Japanese female complained of swelling on the left side of parotid region. Clinical examination revealed a swelling on the lower lobe of the left parotid gland. The lesion was firm but non-tender and was not attached to adjacent structures. A clinical diagnosis of benign salivary gland tumor was reached, and surgical excision was performed under general anesthesia. Histopathological examination revealed an intact parotid gland capsule with isomorphic and basaloid cells within scanty cytoplasm. In addition, an admixture of hyperplasia and proliferation of the intercalated ducts, the presence of zymogen granules, the absence of solid nests, and a peripheral palisaded arrangement of the cells were observed. Based on these findings, a diagnosis of ADP/H was confirmed. ADP/H is a non-tumorous lesion; therefore, tumor involvement should be ruled out before the diagnosis is reached.

A Symptomatic Case of Adenomatous Ductal Proliferation/Hyperplasia with a Large Cystic Lesion

Adenomatous ductal proliferation/hyperplasia (ADP/H) of the salivary gland, a rare asymptomatic nonneoplastic lesion that histopathologically resembles basal cell adenoma, is typically incidentally identified in resected specimens of other salivary diseases such as tumors and chronic sialadenitis. A 70-year-old male was referred to our hospital with a 9-month history of continuous swelling in the left parotid region. A physical examination revealed a soft mass in the left parotid gland, which was identified as a cystic mass by computed tomography. A parotid tumor with cystic components was suspected, and partial parotidectomy was performed under general anesthesia. The histopathological findings were consistent with the diagnosis of ADP/H of the salivary gland. This case report emphasizes the necessity for a proper diagnosis of ADP/H of the salivary gland. Further large case series are required for a modification of the definition of ADP/H for its correct diagnosis.

Salivary gland hybrid tumour revisited: could they represent high-grade transformation in a low-grade neoplasm?

Salivary gland hybrid tumour, first described in 1996, is a very rare neoplasm for which exact morphological criteria have not been universally agreed upon. In contrast, the concept of high-grade transformation (HGT) in salivary neoplasms has been widely accepted during the last decade, and the number of reported cases is rapidly increasing. A review of the literature revealed 38 cases of hybrid tumour reported in 22 publications. During approximately the same time period, well over 100 cases of HGT in salivary neoplasms have been reported. There are important histological similarities between hybrid tumours and salivary tumours with HGT. In the latter, containing one tumour component of low-grade malignancy and the other of high grade, the two tumour components are not entirely separated and appear to originate in the same area. Virtually, all cases reported as hybrid tumour had no clear lines of demarcation between the two tumour types. We are inclined to suggest that most of the 38 cases of hybrid tumours described in the literature would today better be called tumour with HGT rather than hybrid tumour. The relative proportion of the two components may vary, and the high-grade component is sometimes very small, which emphasises the importance of very generous sampling of the surgical specimen. The molecular genetic mechanisms responsible for HGT, including what used to be called hybrid tumour, remain largely unknown. Abnormalities of a few genes (including p53, C-MYC, cyclin D1, HER-2/neu) have been documented. As insufficient data exist on gene abnormalities in these lesions, conclusions as to whether or not they have a common origin and which mechanisms are involved in transformation cannot be drawn. Due to the small number of cases reported, many of which lack follow-up details; indicators of prognosis of hybrid tumours are not available, but their behaviour seems to be similar to that of tumours with HGT, i.e. an accelerated aggressive course. HGT of salivary gland neoplasms greatly influences macroscopic and microscopic evaluation of the specimen but also, given the high incidence of metastases and morbidity, carries significant treatment implications.

Hybrid Intercalated Duct Lesion of the Parotid: Diagnostic Challenges of a Recently Described Entity with Fine Needle Aspiration Findings

Intercalated duct lesions (IDL) of the salivary glands are recently described, and encompass both hyperplasia and benign neoplasms that remain incompletely understood. IDLs have been linked to various benign and low-grade malignant salivary gland neoplasms. We herein present a case of a 77 year old woman with an IDL of the parotid composed of both a hyperplastic and an adenomatous component and report, for the first time, the fine needle aspiration findings of such a lesion. This case illustrates the morphologic spectrum of an IDL, as well as challenges in rendering an accurate cytological and histologic diagnosis. The potential diagnostic pitfalls presented by the hybrid pattern of this lesion are also discussed.

Basal cell adenocarcinoma and Basal cell adenoma of the salivary glands: a clinicopathological review of seventy tumors with comparison of morphologic features and growth control indices

Basal cell adenoma and basal cell adenocarcinoma represent uncommon basaloid salivary gland neoplasms that show marked morphologic similarity. We wished to compare clinical outcome and morphologic features as well as growth and proliferation associated markers for both neoplasms. We reviewed the pathologic features of 70 neoplasms diagnosed as basal cell adenoma or basal cell adenocarcinoma. Observations included maximum mitotic activity and presence or absence of invasion into surrounding normal tissues as well as immunohistochemical studies for Ki-67, caspase 3, p53, and bcl-2. Establishing malignancy on the basis of invasion into surrounding benign tissues, 41 basal cell adenomas and 29 basal cell adenocarcinomas were identified. For tumors with follow-up, recurrence rates were 6.7 % for basal cell adenoma and 16.7 % for basal cell adenocarcinoma. One patient with basal cell adenocarcinoma had distant metastases and died of disease. Overall basal cell adenocarcinomas showed significantly higher values for growth and proliferation markers compared to basal cell adenomas. Salivary gland basal cell adenoma and basal cell adenocarcinoma show morphologic similarity. Basal cell adenocarcinoma can exhibit a locally aggressive behavior and has potential metastatic behavior. The overall mitotic rate and Ki-67 expression were higher in basal cell adenocarcinoma compared to basal cell adenoma, but overlap between the results of these observations in each tumor did not allow for accurate diagnosis or prediction of outcome in individual cases. We conclude that morphologic observation of local tissue invasion is the best marker for separating basal cell adenoma from basal cell adenocarcinoma.