[Morphology of salivary gland diseases]

"Pleomorphic adenoma in salivary glands: Insights from a 100-patient analysis"

Introduction

Pleomorphic adenoma (PA) is a benign epithelial tumour originating from the salivary gland, specifically the parotid gland. This study aims to comprehensively analyse the clinical and pathological features of PA by examining the characteristics of the tumour, including its histological structure and immunohistochemical profile.

Materials and Methods

Over 8 years, beginning in October 2015 and ending in October 2023, an exhaustive retrospective study was conducted in the Department of Pathology, Kasturba Medical College, Mangalore, Manipal University, Karnataka, India. The research focused on 100 cases of pleomorphic adenoma and involved a meticulous examination of the clinical and pathological characteristics obtained by retrieving the pertinent files.

Results

Out of all the primary tumours, the majority (n = 70) was found in the parotid gland, followed by PA that developed from the minor salivary glands of the palate (n = 07), the submandibular gland (n = 17), and the lacrimal gland (n = 04). Only two cases had a primary tumour located in the lips. Females were more susceptible to these tumours than males. The parotid gland tumours showed a distinct trend in laterality, with 73 cases observed on the right side. In 85%, the initial symptom of the condition was painless swelling.

Conclusion

Salivary gland PA is typically a benign tumour. However, a subset of these tumours can exhibit a malignant phenotype. The preferred treatment is surgical excision with adequate margins.

Are salivary amylase and pH - Prognostic indicators of cancers?

BACKGROUND

Saliva, "Mirror of body's health" has long been of particular interest as a substitute for blood for disease diagnosis and monitoring. The radiation effects on salivary glands are of particular interest in which salivary amylase is a good indicator of salivary glands function. Thus, estimation of these parameters represents a reasonable approach in evaluation of patient's risk for disease occurrence, intensity and prognosis.

AIM OF STUDY

To evaluate and compare the pH and amylase levels in saliva of cancer patients prior to treatment, patients during treatment.

MATERIALS AND METHODS

Saliva samples of 90 individuals were taken which were divided into 3 groups - 30 individuals without cancer, 30 cancer patients prior treatment and 30 cancer patients during treatment. Materials used were pH strips and pH meter, Salivary Amylase assay.

RESULTS

Statistical analysis - ANOVA with post-hoc Tukey's test. 1) Significant decrease in salivary amylase levels - in cancer patients, during treatment when compared to others. 2) Significant decrease in salivary pH levels in newly diagnosed cancer patients prior to treatment.

CONCLUSION

To conclude, pH strips and pH meter showed to be a useful tool in the measurement of pH of saliva in individuals with and without cancer. This study showed that cancer patients without treatment have a lower pH of saliva. Treatment increased the pH of the saliva to a more alkaline level whereas amylase levels decreased in those subjects. Therefore those parameters can be an area of further research with an increased sample size, which in-turn may help in opening the doors for new dimension in non invasive prognostic markers.

Distribution of intermediate filaments and actin microfilaments in parotid autoimmune sialoadenitis of Sjögren syndrome

In order to study the importance of myoepithelial cells in the formation of parotid epi-myoepithelial islands of the autoimmune sialoadenitis in Sjögren's syndrome, the distribution of cytoskeletal elements has been investigated by electron and immunofluorescence microscopy. Antibodies to intermediate filament proteins--prekeratins, desmin and vimentin--were used as well as a 'DNase I/anti-DNase I' immunohistochemical procedure to detect actin microfilaments for characterization of myoepithelial cells compared to the other types of parotid epithelial cells. Two types of prekeratin antibodies were raised. One of these reacted preferentially with myoepithelial cells. The same type of antiserum also showed a bright fluorescence in cells located peripherally in the epi-myoepithelial islands. These island cells, however, exhibited only a very low actin microfilament content and were thus not ordinary myoepithelial cells. The other type of prekeratin antibodies reacted with all types of parotid epithelia, except acinar secretory epithelium. They also stained all island epithelial cells, but the reactivity was less in cell regions with pronounced lymphocyte infiltration. The heterogeneity between the island epithelial cells, immunohistochemically as well as ultrastructurally, indicates different stages of island formation. Interepithelial lymphocytes showed less vimentin and actin filament content in comparison with lymphoid cells outside the islands. Conclusively, typical epi-myoepithelial islands are composed of metaplastic epithelial cells of intercalated duct origin and invaded lymphoid cells, and ordinary myoepithelial cells are lacking.

Presumptive sialadenosis in a cat

A cat was presented with signs associated with enlargement of the mandibular salivary glands. Histological findings were normal, consistent with a diagnosis of sialadenosis, and the cat responded to symptomatic treatment with oral phenobarbitone.

DNA analysis at p53 locus in carcinomas arising from pleomorphic adenomas of salivary glands: comparison of molecular study and p53 immunostaining

Where and how frequently p53 abnormalities are involved in the development of pleomorphic adenoma (PA) and its malignant progression to carcinoma was investigated. The presence of p53 gene abnormalities was analyzed in eight patients with carcinoma in pleomorphic adenoma (CPA) by polymerase chain reaction (PCR)-based assays and immunohistochemistry. Normal salivary gland tissue, adenomatous, transitional and carcinomatous areas were microdissected from archival microslides and analyzed for allelic deletions of the p53 gene using two microsatellite markers at the p53 locus; dinucleotide (CA)n repeat and pentanucleotide (AAAAT)n repeat. Loss of heterozygosity (LOH) of the p53 gene was detected in 57% of adenomas, 86% of transitional lesions and 86% of carcinomas. In contrast, overexpression of p53 oncoprotein was noted immunohistochemically in 13% of adenomas, 50% of transitional areas and 75% of carcinomas. All of the tumors with immunoreactivity for p53 oncoprotein demonstrated LOH. Moreover, when LOH was present in adenomatous or transitional areas, the identical LOH was always detected in the corresponding carcinomatous areas in the same CPA tumors. These findings indicate that p53 gene mutation is an early event and occurs frequently at an early stage of precancerous lesions and may be responsible for most cases of malignant transformation of PA.

Mutations associated with carcinomas arising from pleomorphic adenomas of the salivary glands

Pleomorphic adenoma (PA) is the most common benign tumor of salivary glands. Carcinomas in pleomorphic adenomas (CPAs) may arise by malignant transformation of the epithelial components of PAs. Occasionally, transitional zones containing cells with histological features intermediate between those of the benign PA and carcinomatous components of CPA are identified. After careful microdissection of archival microslides, the authors studied 12 cases of CPAs and their attendant adenomatous and transitional areas for mutations in the p53, RB, and K-ras genes, and at chromosomal loci 5q and 9p. The authors failed to find mutations in the K-ras gene or 9p locus. A relatively high rate of mutations (loss of heterozygosity [LOH] and microsatellite alterations) at the p53 gene were detected in CPAs (58%), and at somewhat lower frequencies at the RB gene (33%) and chromosomal location 5q (17%). Mutational frequency in the associated transitional and adenomatous areas were slightly lower than in the corresponding CPAs. No mutations were detected in adenomatous or transitional areas unless they also were present in the corresponding CPAs. Mutations of these three genes were absent in four cases of CPA, and in seven PAs without malignant change. These findings indicate that most CPAs arise from adenomas as the result of mutations in the three genes, especially p53. In addition, other, as yet unidentified genes may also be involved both in the development of PA and in its malignant progression to CPA. Mutational analysis of PAs may provide information of prognostic importance.

Radioprotection of minipig salivary glands by orciprenaline-carbachol. An ultrastructural and semiquantitative light microscopic study

Parotid and submandibular glands of miniature pigs were exposed to 36 Gy X-irradiation given as 6 x 6 Gy in 3 weeks. Half of the animals received orciprenaline and carbachol before each dose. The effects were analysed 6 months later by light and electron microscopy. Ultrastructural examination showed less change in the pretreated glands. Semi-quantitative light microscopic data confirmed the significance of the differences. Acinar cells of both glands were significantly more numerous (P less than 0.01) and the cells were better preserved (P less than 0.01) in the pretreated group. The effect was more pronounced in the parotid gland, which appeared almost normal. Intercalated ducts of the parotid glands (P less than 0.01) and striated ducts of the submandibular glands (P less than 0.05) showed less change in pretreated animals. The findings confirm the radioprotective effect of pharmacologically induced degranulation of acinar cells. The biological effects of the radiation schedule (cumulative radiation effect value 18.76) as well as the dosage of orciprenaline and carbachol are within the normal range of medical treatment. Similar results may be expected from future studies in man.

Differential diagnosis and surgical management of parapharyngeal masses: review and an unusual illustrative case

Diagnosis and management of swellings of the parapharyngeal space are difficult because of the inaccessibility of the region, which contains part of the parotid gland with major vascular and neural structures that may be subject to disease. An unusual case of a spherical mass with a calcified margin within the parapharyngeal space is presented; it illustrates an approach to diagnosis and management.

The myoepithelial cell: embryology, function, and proliferative aspects

Myoepithelial cells form an integral part of the secretory and ductular portion of most glands. They share a common origin with lumenal epithelial cells and influence proliferation and differentiation of developing terminal glandular buds by producing a scaffold of basement membrane proteins. Their contractile capacity, controlled by hormonal and neural mechanisms, plays an important role in propulsion of secretions. Furthermore, myoepithelial cells maintain glandular structural integrity and transport metabolites to secretory cells. The advent of modern immunochemistry made identification of specific myoepithelial cell markers possible which facilitated studies on their presence and behavior in disease processes. Although the significance of many myoepithelial alterations is speculative, some have proved valuable in determining the histogenesis of glandular lesions.

Malignant epithelial tumours associated with autoimmune sialadenitis

Malignant epithelial tumours associated with autoimmune sialadenitis are rare in white races but occur more often in those of Eskimo or oriental descent. Ultrastructurally these tumours are squamous in origin, and they may arise from the epithelial component of autoimmune sialadenitis. The two cases reported are the first described in natives of this country, and in one, a case of parotid tumour, autoimmune sialadenitis preceded the development of undifferentiated carcinoma by 12 years; the other, a submandibular lesion, indicates some diagnostic difficulties that were found. This condition deserves wider recognition, as adequate primary treatment may result in long term survival.

The clinical picture of benign lympho-epithelial lesion

The histopathological diagnosis 'benign lympho-epithelial lesion' characterizes the major salivary gland disease in Sjögren's syndrome. It is not known if all cases with microscopically diagnosed benign lympho-epithelial lesion are variants of Sjögren's syndrome. The present clinical investigation showed that in 19 patients with the microscopical diagnosis of lympho-epithelial lesion, 84% fulfilled all criteria of Sjögren's syndrome. The rheumatoid factor and/or antinuclear factor was found in 84% and M-component was present in 16%. Sialography revealed sialectasis in all parotid glands. Salivary gland enlargement was found in 79%, and keratoconjunctivitis sicca in 89% of the patients. Systemic disease was found in 32%. The disease in the 2 patients with M-component took a malignant course, culminating in immunoblastic sarcoma and myelomatosis. The clinical diagnosis 'autoimmune sialadenitis' is proposed for the oral and salivary gland component is Sjögren's syndrome.

The expression of different intermediate-sized filaments in human salivary glands and their tumours

The intermediate-sized filaments can be divided into several groups which are characteristic of different types of tissues (e.g.: epithelial, mesenchymal, muscle, astrocytic and neural origin). Antibodies specific for some of these filament types have been used to analyse a group of salivary gland tumours. Prekeratin-positive cells were seen in the normal gland, cystadenolymphomas, mucoepidermoid tumours, and squamous cell carcinomas which are all tumours of epithelial origin. The pleomorphic adenomas showed the presence of some cells which appeared to contain both prekeratin and vimentin. The results are discussed with respect to their histogenetic implications.

Immunohistochemical detection of carcinoembryonic antigen (CEA) in parotid gland carcinomas. Analysis of 52 cases

The presence of CEA in parotid gland tumours was studied by immunohistochemical methods. 52 cases were analysed. 7 of 8 adenocarcinomas, 3 of 5 cystadenocarcinomas, 3 of 4 adenoid cystic carcinomas and all 3 salivary duct carcinomas were positive for CEA. 5 of 8 squamous cell carcinomas and 9 of 21 carcinomas in a pleomorphic adenoma were also positive for CEA. The anaplastic carcinomas were negative. The distribution pattern of the presence of CEA in the carcinomatous and the adjacent normal or inflamed tissue was analysed. The results are discussed with regard to their histogenetic and diagnostic implications.

Immunocytochemical demonstration of filamentous structures in the parotid gland. Occurrence of keratin and actin in normal and tumoral parotid gland with special respect to the myoepithelial cells

The aim of this study was to analyze the filament distribution in the parotid gland and their tumors. A correlation to the histogenetic implications and histological properties was attempted. Normal rat and human parotid glands as well as pleomorphic adenomas and squamous cell carcinomas of this gland were examined by the indirect immunoperoxidase technique using antibodies to the keratin polypeptide of 67,000 dalton, and 55,000 dalton and anti-actin auto-antibodies. Both keratin and actin antigens were demonstrated in the duct system and in the myoepithelial cells of the normal salivary glands. The acinar cells remained negative. In pleomorphic adenomas, there were numerous keratin-positive spindle-shaped cells which represented the so-called myoepithelial cells. These cells were demonstrated to contain actin, too. The tubular duct-like structures were labeled by keratin antiserum and by anti-actin auto-antibodies. In squamous cell carcinomas, the majority of the tumor cells were strongly labeled by keratin antibodies. Actin was detected in these malignant cells, too. Our results show important differences in the cellular elements of the normal salivary glands with regard to their filament distribution. In normal and tumoral conditions, our findings support the hypothesis of the epithelial nature of the myoepithelial cells. Our preliminary results encourage the research of filamentous structures for scientific and diagnostic purposes.

Immunoglobulin-containing plasma cells in chronic parotitis and malignant lymphomas of the parotid gland. Comparing immunocytochemical observations of frequency and localization

IgA-containing plasma cells in the periductal gland tissue are part of the special secretory immune system of the salivary glands. The reaction of Ig-containing plasma cells (localization, frequency, specific Ig-content) was analyzed by the indirect immunoperoxidase method in chronic recurrent parotitis (9 cases), chronic myoepithelial parotitis (benign lymphoepithelial lesion, Sjögren's syndrome; 8 cases), and malignant lymphoma associated with chronic myoepithelial parotitis (11 cases). The following results were obtained: 1. In chronic recurrent parotitis, parallel to the increase in IgA in the salivary secretion, a marked multiplication of IgA-containing plasma cells was found in the inflammatory infiltrate and the remaining non-inflamed periductal parenchyma of the parotid gland. In the marginal zone of inflammation, a slight increase of IgG-containing plasma cells was also observed. 2. In chronic myoepithelial parotitis, the total plasma cellular infiltration was slightly less distinct than in chronic recurrent parotitis. The most remarkable increase in Ig-containing plasma cells developed in the marginal zones--away from the myoepithelial cellular islands--as well as in the area of ductular proliferations, and was characterized by a strong increase of IgG-containing plasma cells. At the same time, a slight increase of IgM-containing plasma cells was observed. No plasma cells were found in the myoepithelial cellular islands. 3. In the malignant lymphomas associated with myoepithelial parotitis, which were mainly highly differentiated lymphomas (immunocytomas, centrocytic-centroblastic lymphomas) and rarely poorly differentiated immunoblastic lymphomas, there was a distinct decrease of IgG-containing plasma cells when compared with the numbers in this group without lymphoma. The differing degrees of prevalence and Ig-content of the plasma cells partly describe the change taking place in the local secretory immune system of the parotid gland. The possible relationships between chronic recurrent parotitis and auto-immune myoepithelial parotitis on one hand and the stages of transition (prelymphoma) to malignant lymphoma on the other, are discussed.

Histologic subclassification of the cystadenolymphoma of the parotid gland. Analysis of 275 cases

Cystadenolymphomas (CAL) of the parotid gland are variable in their epithelial differentiation and the ratio of the epithelial tumor component to lymphoid stroma. Two hundred and seventy five cases of CAL from the files of the Salivary Glands Register of the Institute of Pathology, University of Hamburg (1965-1979) were analysed. Their pathogenesis from parenchyma included in regional lymph nodes is discussed. The following subclassification was established. 1. Depending on to the ratio of epithelial tumor component to lymphoid stroma, three subtypes were distinguished. Subtype 1, "typical CAL" with an epithelial tumor component of 50%, amounted to 77% of all cases of CAL studied. Oncocytic differentiation and focal metaplasia to goblet cells or squamous epithelium was also found. 13.5% of CAL were classified as subtype 2, "stroma-poor CAL" with an epithelial tumor component of 70 to 80%. The tumor structure was similar to that of an oncocytoma in places. Two per cent of the CAL were in subtype 3, "stroma-rich CAL" with an epithelial tumor component of only 20 to 30%. Subtype 3 was found solely in men. The average age at presentation (61 years) was slightly lower than that of all the cases studied (65 years). 2. In 7.5% of the cases large areas of squamous cell metaplasia and regressive changes was found within a CAL. These cases were classified as subtype 4 ("metaplastic CAL"). The average age was 67 years. The case histories showed that 20% of these metaplastic CAL had previously been irradiated. 3. Bilateral CAL was found in 7.5% of the cases. In 4% multifocal CAL occurred in the parotid gland unilaterally. Recurrences were observed in 2% of all CAL. 4. Carcinoma in CAL is rare (we found two cases in our own material). In 50% of all cases reported radiotherapy was mentioned in the case histories. 5. Malignant tumors coincident with CAL were recorded in 3% of the cases. 6. The lymphoid stroma showed reaction patterns similar to those of the regional lymph nodes. These included granulomatous changes (foreign body granuloma with cholesterol deposits, tuberculosis) and tumor metastases. In the neighborhood of oncocytic tumor epithelium focal accumulations plasma cells forming IgA and IgG were found. Metaplasia to squamous epithelium is believed to be caused by circulatory disturbances, irradiation, and other noxae. In the differential diagnosis of the stroma-poor subtype 2, oncocytoma and cystic sialadenoma must be excluded, and in the differential diagnosis of subtype 4 (the metaplastic CAL), sebaceous adenoma, mucepidermoid tumor, squamous cell carcinoma, lymphoepithelioma, and other non-tumorous lesions of the parotid gland (lymphoepithelial cysts, myoepithelial parotitis) must be ruled out. Our findings suggest that CAL develops from parenchyma included in parotid lymph nodes with the oncocytic ductal epithelium representing the neoplastic component.

[Electronmicroscopic observation on acinic cell tumors of the parotid gland]

Under the electronmicroscope we observed a case of an acinic cell tumor of the left parotid gland. The patient was a 63-year-old woman who has suffered three times from local recurrences. The cytoplasma of the tumor cells showed the well-organized mitochondria, rouch endoplasmic reticula, Golgi's complexes and other organellas. Especially the cytoplasmas of the tumor cells, which formed acinus-like lumens, contained various-shaped secretory granules in great numbers. In addition, pycnotic-nucleated oncocytes with secretory granules could be observed.

[Carcinomas in papillary cystadenolymphomas of the parotid gland--definition and differential diagnosis (author's transl)]

Within a collective of 1431 salivavry gland tumors of the salivary gland register (1965--1976) an observation has been done, which has been classified as a "carcinoma in a papillary cystadenolymphoma". Corresponding to the "carcinoma in a pleomorphous adenoma" of the WHO-classification of salivary gland tumors the terminus "carcinoma in a cystadenolymphoma" is further defined. 6 additional cases from the literature are reviewed. The possible role of epithelial metaplasia and of a proceding radiation in the development of carcinomas in cystadenolymphomas are discussed. The following other tumors have to be differentiated from a carcinoma in a cystadenolymphoma: Metastases of other tumors beyond a cystadenolymphoma; malignant lymphoepithelial lesions (predominantly malignant lymphomas in a preexisting immune-sialadenitis of the myoepithelial sialadenitis type; rare carcinomas), and lymphoepitheliomas.

Classification of the pathohistology of diseases of the salivary glands - review of 2,600 cases in the Salivary Gland Register

Three major disease groups emerge from a classification of the pathohistology of 2,600 salivary gland preparations in the salivary gland register (from 1965 to 1974): salivary gland tumors (41%), salivary gland inflammations (26%), and sialadenosis (6%). Mucoceles (2%) and salivary gland cysts (1.5%) are seen less often. It is diagnostically important that lymph node changes in the area of the salivary glands (lymphadenitis, lymphomas, etc.) are worked up under suspicion of a primary salivary gland disease. Sialadenosis involves a primary, vegetative neuropathy, which is accompanied by enlargement of acinar cells. Under the heading of chronic sialdenitis, we fine 50% socalled Küttner tumors of the submandibular gland, 21% chronic relapsing parotitis, 14% chronic inflammations of the minor salivary glands and the sublingual gland, and 12% immune sialadenitis (myoepithelial sialadenitis in Sjögren's syndrome and epitheloid cell sialadenitis in Heerfordts syndrome). A more than average number of immune sialadenitis cases develop into malignant lymphomas (4 cases in the salivary gland register). The 1,067 tumor cases containing of 929 epithelial tumors (87%), 89 mesenchymal tumors (hemangiomas, lymphangiomas, lipomas, neurofibromas, sarcomas) and 49 metastases or periglandular tumors. Epithelial tumors were grouped on the basis of the World Health Organization (WHO) classification. Benign tumors (71.5%) consisted of pleomorphic adenomas (51.5%) and monomorphic adenomas (50%). After the pleomorphic adenomas, cystadenolymphomas (over 10%) represented the most frequent benign salivary gland tumor. On the basis of epithelial and stromal differentiation, pleomorphic adenomas were subdividied into four subtypes (stroma-rich and stroma-poor adenomas). The malignant tumors consisted of acinar cell tumors (2.5%), mucoepidermoid tumors (6%), and carcinomas at various levels of differentiation (adenoid-cystic carcinomas, 6.5%; adenocarcinomas, 2%; squamous cell carcinomas, 2%; carcinomas in pleomorphic adenomas, 4%; miscellaneous carcinomas - salivary duct carcinomas, clear-cell carcinomas, undifferentiated carcinomas, 5.5%). Differences in age and sex distribution, localization, malignity metastases, recidivism, et