Eosinophilic sialodochitis: redefinition of 'allergic parotitis' and 'sialodochitis fibrinosa'

Confirmation of eosinophilic sialodochitis by terminal duct biopsy

OBJECTIVE

To analyse the histopathological features of eosinophilic sialodochitis by using terminal duct biopsy.

METHODS

Sixty-five patients with suspected eosinophilic sialodochitis and four with chronic obstructive sialadenitis were prospectively enrolled. Clinical features, laboratory tests and sialograms were comparatively analysed. Terminal duct biopsy of the parotid or submandibular glands was performed concomitantly with endoscopy-assisted duct dilatation to determine the histopathological features of eosinophilic sialodochitis.

RESULTS

Based on eosinophil quantification, the samples of suspected patients were scored as 'definite', 'highly suspected' and 'negative' in 26 (40%), 15 (23.1%) and 24 (36.9%) cases, respectively. Gland types and peripheral blood eosinophil counts were significantly different among these three groups. The proportions of itching glands, mucus plug exudations and elevated immunoglobulin E levels were higher in the 'definite' group than in the other two groups; however, the intergroup differences were insignificant. The primary pathological features of eosinophilic sialodochitis were abundant eosinophils and lymphocytes infiltrated around the duct, degranulation of eosinophils, extensive fibrosis and scattered mastocytes. Periductal eosinophils were not found in cases of chronic obstructive sialadenitis.

CONCLUSION

Our findings suggest that terminal duct biopsy is safe and valuable for the pathological confirmation of eosinophilic sialodochitis, and can be used simultaneously with endoscopy-assisted duct dilatation.

Eosinophilic mucus diseases

Eosinophilic inflammation is primarily characterized by type 2 immune responses against parasitic organisms. In the contemporary human being especially in developed countries, eosinophilic inflammation is strongly associated with allergic/sterile inflammation, and constitutes an undesired immune reaction. This situation is in stark contrast to neutrophilic inflammation, which is indispensable for the host defense against bacterial infections. Among eosinophilic inflammatory disorders, massive accumulation of eosinophils within mucus is observed in certain cases, and is often linked to the distinctive clinical finding of mucus with high viscosity. Eosinophilic mucus is found in a variety of diseases, including chronic allergic keratoconjunctivitis, chronic rhinosinusitis encompassing allergic fungal sinusitis, eosinophilic otitis media, eosinophilic sialodochitis, allergic bronchopulmonary aspergillosis/mycosis, eosinophilic plastic bronchitis, and eosinophilic asthma. In these pathological conditions, chronic inflammation and tissue remodeling coupled with irreversible organ damage due to persistent adhesion of toxic substances and luminal obstruction may impose a significant burden on the body. Eosinophils aggregate in the hyperconcentrated mucus together with cell-derived crystals, macromolecules, and polymers, thereby affecting the biophysical properties of the mucus. This review focuses on the clinically significant challenges of mucus and discusses the consequences of activated eosinophils on the mucosal surface that impact mucus and persistent inflammation.

Clinical features of adult patients with allergic parotitis

Background

Allergic parotitis (AP), due to its non-specific symptoms, frequently poses a diagnostic challenge, leading to cases being overlooked or misdiagnosed by clinicians.

Objective

This study aimed to elucidate detailed clinical characteristics and common diagnostic indicators of AP.

Methods

A comprehensive review and analysis of medical records was conducted from patients diagnosed with AP, encompassing demographic, clinical, and laboratory data, at the Affiliated Stomatological Hospital of Nanjing Medical University between January 2019 and March 2022.

Results

The study enrolled 17 patients, evidenced by an average age of 36.00 ± 12.95 years. Common presentations of AP among the patients included notable symptoms such as parotid gland swelling, associated pain, and xerostomia. Ten patients had other atopic diseases. Palpation revealed the affected parotid glands to be soft and nodular, with an elevated local skin temperature. The unstimulated whole saliva flow rate was decreased. Ultrasonography demonstrated increased volume, reduced echo heterogeneity, and lymph node enlargement in the affected parotid glands. All cases observed increased serum salivary amylase and total IgE levels. Investigation of food allergens and inhaled allergen-specific IgE showed that all patients had suspected food allergies. Food provocation tests (FPT) induced AP in 13 cases, confirming the role of food allergens.

Conclusion

Food allergens are involved in the etiology of AP, underscoring the importance of comprehensive clinical evaluation, including symptoms, signs, and confirmatory auxiliary tests, such as FPT, for accurate diagnosis and differentiation from other salivary gland pathologies.

Cystic lesions in the salivary gland. Pitfalls to be avoided on cytology

Cystic lesions of the salivary glands are very uncommon entities. However, on occasion, some neoplasms of the salivary glands show a cystic component, which may be predominant or only partially cystic. Basal cell adenoma, canalicular adenoma, oncocytoma, sebaceous adenoma, intraductal papilloma, epithelial-myoepithelial carcinoma, intraductal carcinoma, and secretory carcinoma are such cystic entities. Cystic degeneration and necrosis, which can develop within solid tumours, represent another possibility. The ability to recognise this type of lesion is a challenge in diagnostic cytology because hypocellular fluid is frequently recovered. Furthermore, evaluating all of the differential diagnoses for cystic lesions of the salivary glands is helpful in obtaining the correct diagnosis. Herein, we evaluate the various types of cystic lesions within the salivary glands.

Unusual Presentation of Primary Hyper-IgE-Related Salivary Gland Disease in a 13-Year-Old Male

Adenomas are common pathologies of the salivary glands that are often associated with the major salivary glands and occur in the fourth to sixth decades of life. They are seldom seen in the pediatric age group and rarely in the minor salivary glands. Autoimmune sialadenosis of the minor salivary glands is a new phenomenon that has seldom been reported in the literature, with as few as three cases. Histopathological examination of the excised specimen is the definitive diagnosis, and these lesions have to be differentiated from adenomas and low-grade malignancies of the minor salivary glands. Management strategies of these lesions are extremely variable, ranging from wait-and-watch principle to the use of immunosuppressants and excision of the gland. This case report discusses the etiopathogenesis of the autoimmune sialadenosis and the management strategies.

Clinical Manifestations and Genetic Influences in Sulfonamide-Induced Hypersensitivity

Drug hypersensitivity is an inflammatory or immune reaction induced by drugs. It can be fatal if not appropriately treated and cause the risk of long-term complications. Sulfonamides are classified as antimicrobial drugs with a broad spectrum effective for gram-positive and gram-negative bacteria. This antibacterial agent works by competitively inhibiting folic acid synthesis, which prevents the growth and proliferation of microorganisms. In its use as antibiotics, sulfonamides can also cause adverse reactions in specific individuals. It has been widely reported that sulfonamide antimicrobials cause hypersensitivity reactions mediated by IgE or T cells. This review identifies symptoms or signs that can appear, as well as genes associated with sulfonamide hypersensitivity reactions, as sulfonamide may cause hypersensitivity in the form of uveitis, skin rash, Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), parotitis, angioedema, drug reaction with eosinophilia and systemic symptoms (DRESS), and pruritus. In addition, several genes were found to be associated with sulfonamide hypersensitivity, including HLA-A29, HLA-B12, HLA-DR7, HLA-B44, and HLA A*11:01.

Primary Hyper-IgE-Related Salivary Gland Disease: A New Disease Entity

OBJECTIVES

To clarify the clinicopathological characteristics of primary hyper-IgE-related salivary gland disease (PHIESD), which is a newly proposed entity.

METHODS

Fifteen consecutive patients pathologically diagnosed with chronic sialadenitis were enrolled, and their clinicopathological features were comprehensively analyzed.

INCLUSION CRITERIA

(1) multiple salivary gland enlargement; (2) elevated serum IgE and/or IgE-positive cell infiltration in salivary gland tissues; (3) histology-confirmed lymphoplasmacytic infiltration; (4) exclusion of other known diseases.

RESULTS

The male-to-female ratio was 5:10. The median age was 21 (range, 3-63) years. The average number of affected glands was 3.7 ± 1.4. Submandibular, parotid, and sublingual glands were involved in 15, 8, and 2 patients, respectively. Comorbid diseases included allergic diseases in seven patients and autoimmune diseases in two. Elevated serum IgE (median 175 kU/L) was seen in all patients. Serum IgG4 was slightly elevated in three patients. Histologically, most patients had mild lesions, including mild lymphocyte infiltration (60%) and focal fibrosis (66.7%). Lymphoid follicular formation (53.3%), moderate to severe lymphocytic inflammation (40%) and severe fibrosis (33.3%) were also observed. Immunohistochemically, IgE-positive cells infiltrated mainly around the ducts, with scattered infiltration of IgG4-positive, mast, and interleukin-4 positive cells. During follow-up (median, 46 months) of ten patients without intervention and two with immunosuppressive therapy, no significant changes in gland size or serum IgE level were noted.

CONCLUSIONS

PHIESD manifests as homogeneous enlargement of multiple salivary glands and elevated serum IgE. Histopathology further verifies the diagnosis. It might be associated with anaphylaxis or autoimmune dysfunction. Conservative treatment is suggested.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

[Studies on newly recognized chronic sialadenitis]

Some kinds of chronic sialadenitis were recognized during the recent years. They have specific pathogenesis, clinical and histopathologic appearances, and require specific treatment. IgG4-related sialadenitis (IgG4-RS) is one of the immune-mediated diseases, characterized by tumefactive lesions. The incidence of IgG4-RS obviously increased during the past 30 years. The study on the potential relationship between occupational exposure to chemical substances and the incidence of IgG4-RS showed that subjects with occupational exposure to agents known to cause IgG4-RD had an increased risk for IgG4-RS. Surgical excision of involved SMG could not control the disease progression, which is not recommended for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents is effective for treating IgG4-RS, and restores salivary gland function. Radioiodine induced sialadenitis (RAIS) is one of the common complications of postoperative adjuvant treatment of differentiated thyroid cancer by ¹³¹I. The incidence of the disease is related to radiation dosage. Clinically, the patients suffered from swelling and tenderness in the buccal or submandibular regions, especially during the mealtime. Imaging appearances are similar to those of chronic obstructive sialadenitis. Conservative managements, such as gland massage, sialagogues, are the mainstream methods in the treatment of RAIS. Sialendoscopy is feasible for RAIS, but not as effective as conventional obstructive sialadenitis (COS). Therefore the prevention of RAIS is crucial. Eosinophilic sialodochitis (ES) is a new type of chronic inflammatory disease of the salivary gland related to allergy. It has characteristics of swelling of multiple major salivary glands, strip-like gelatinous plugs discharged from the duct orifice of the gland, elevated level of serum IgE and eosinophils in peripheral blood, infiltration of eosinophils and IgE positive plasma cells in the tissues, allergic history, increased expression of allergy-related cytokines, such as IL-4, IL-5, IL-13, and eotaxin, which suggest allergic reactions as a potential pathogenesis of the disease. The clinical, laboratory, histological, and immunohistochemical characteristics of ES are significantly different from conventional obstructive sialadenitis (COS). Therefore, it is suitable to separate ES from COS. Conservative managements, such as self-maintenance therapy and anti- allergic modality are the choices of treatment for ES. Based on the results of our comprehensive studies a new classification of chronic sialadenitis is suggested.

[Studies on newly recognized chronic sialadenitis]

Some kinds of chronic sialadenitis were recognized during the recent years. They have specific pathogenesis, clinical and histopathologic appearances, and require specific treatment. IgG4-related sialadenitis (IgG4-RS) is one of the immune-mediated diseases, characterized by tumefactive lesions. The incidence of IgG4-RS obviously increased during the past 30 years. The study on the potential relationship between occupational exposure to chemical substances and the incidence of IgG4-RS showed that subjects with occupational exposure to agents known to cause IgG4-RD had an increased risk for IgG4-RS. Surgical excision of involved SMG could not control the disease progression, which is not recommended for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents is effective for treating IgG4-RS, and restores salivary gland function. Radioiodine induced sialadenitis (RAIS) is one of the common complications of postoperative adjuvant treatment of differentiated thyroid cancer by 131I. The incidence of the disease is related to radiation dosage. Clinically, the patients suffered from swelling and tenderness in the buccal or submandibular regions, especially during the mealtime. Imaging appearances are similar to those of chronic obstructive sialadenitis. Conservative managements, such as gland massage, sialagogues, are the mainstream methods in the treatment of RAIS. Sialendoscopy is feasible for RAIS, but not as effective as conventional obstructive sialadenitis (COS). Therefore the prevention of RAIS is crucial. Eosinophilic sialodochitis (ES) is a new type of chronic inflammatory disease of the salivary gland related to allergy. It has characteristics of swelling of multiple major salivary glands, strip-like gelatinous plugs discharged from the duct orifice of the gland, elevated level of serum IgE and eosinophils in peripheral blood, infiltration of eosinophils and IgE positive plasma cells in the tissues, allergic history, increased expression of allergy-related cytokines, such as IL-4, IL-5, IL-13, and eotaxin, which suggest allergic reactions as a potential pathogenesis of the disease. The clinical, laboratory, histological, and immunohistochemical characteristics of ES are significantly different from conventional obstructive sialadenitis (COS). Therefore, it is suitable to separate ES from COS. Conservative managements, such as self-maintenance therapy and anti- allergic modality are the choices of treatment for ES. Based on the results of our comprehensive studies a new classification of chronic sialadenitis is suggested.

Common Characteristics and Clinical Management Recommendations for Juvenile Recurrent Parotitis: A 10-Year Tertiary Center Experience

Objective

Juvenile recurrent parotitis (JRP) is a rare disease that may adversely affect normal development and quality of life. The objective of this study was to report on the demographics, characteristics, and treatment outcomes of JRP and to offer evidence-based management recommendations.

Study Design

Retrospective review.

Setting

A single tertiary care pediatric teaching hospital.

Methods

Medical records, imaging studies, and laboratory findings over a 10-year period were retrospectively collected and reviewed, resulting in 41 patients with JRP between the ages of 8 months and 16 years.

Results

Black males aged 2 to 8 years were most commonly affected by JRP. Overall, 18 (44%) patients received ≥3 antibiotics, and 17 (42%) underwent sialendoscopy for treatment. Over 75% of patients had no JRP recurrences after 3 sialendoscopies. The most common imaging approach was computed tomography (42%), and the most frequent laboratory results were elevated amylase (83%) and C-reactive protein (82%). Atopy (61%) and excess weight (42%) were routinely associated with JRP, especially in severe cases.

Conclusion

JRP workup and treatment plans should begin with the least burdening modalities, including over-the-counter analgesics, minimal laboratory studies in the acute phase, and ultrasonography over computed tomography. Clindamycin is an effective initial antibiotic of choice, and severe recurrences may be controlled with sialendoscopy. Optimizing the health of patients with JRP includes managing comorbidities, especially of atopic and overweight origins, which are associated with more severe cases.

Ultrasound in Inflammatory and Obstructive Salivary Gland Diseases: Own Experiences and a Review of the Literature

Background: Ultrasound is established as a diagnostic tool in salivary glands for obstructive diseases such as sialolithiasis and tumors. Concerning inflammatory diseases and in non-sialolithiasis-caused obstruction, much fewer data are available. In recent years, technical development has allowed a better assessment of the gland parenchyma, and knowledge about intraductal pathologies has increased considerably, which has provided new insights and a new interpretation of ultrasound findings. Objectives: To provide a comprehensive review of the literature that includes our own experiences and to point out the state of the art in ultrasound in the diagnostics of inflammatory and obstructive salivary gland diseases, taking adequate techniques and recent technical developments into consideration. Data sources and study eligibility criteria: A systematic literature search was performed in Pubmed using various specific key words. Results: According to the literature results, including our own experiences, ultrasound is of value in up to >90% of cases presenting with inflammatory and/or obstructive diseases. Technical developments (e.g., elastography) and the application of modified ultrasound techniques (e.g., transoral ultrasound) have contributed to these results. Today, ultrasound is considered a first-line diagnostic tool in these diseases. However, in some inflammatory diseases, the final diagnosis can be made only after inclusion of the anamnesis, clinical symptoms, serologic blood tests, or histopathologic investigation. Conclusions: Ultrasound can be considered as a first-line diagnostic tool in obstructive and inflammatory salivary gland diseases. In obstructive diseases, it may be sufficient for diagnostics in >90% of cases. In inflammatory diseases, ultrasound is at least an excellent screening method and can be used to establish the diagnosis in cases of an early suspicion. In all diseases ultrasound can contribute to better management and can be used for monitoring during follow-up.

Eosinophilic sialoadenitis in a patient with severe asthma: a case report

Activated eosinophils can infiltrate various tissues and cause inflammatory tissue damage. Asthma is a typical type of eosinophilic inflammatory disease that occurs in the respiratory system. Eosinophilic sialodochitis and sialoadenitis of the salivary gland are rare diseases clinically characterized by painful swelling. In this report, we present a 68-year-old woman with asthma who presented to our hospital with mandibular swelling. Her asthma had been well controlled with an inhaled combination of a corticosteroid and a long-acting β2 agonist, although she reported a past history of frequent asthma attacks and hospitalization. Laboratory investigation on admission revealed blood eosinophilia (2,673/μL), high levels of total immunoglobulin E (390 U/mL) and immunoglobulin G4 (183 mg/dL). Bone marrow examination showed no evidence of eosinophilic neoplasia. Histological examination of her minor salivary glands disclosed an infiltration of mixed lymphocytes and eosinophils. Chromatolytic eosinophils with Charcot-Leyden crystals were also observed within the edematous dermis and fibrous tissues surrounding the minor salivary gland. The patient was diagnosed with eosinophilic sialoadenitis. Treatment with oral corticosteroids (0.5 mg/kg/day) was initiated. Thereafter, the mandibular swelling improved. This report describes a rare case of eosinophilic sialoadenitis in a patient with severe eosinophilic asthma, for which histopathological and immunefluorescence microscopic analyses were performed.

Allergy-Related Sialodochitis: A Preliminary Cohort Study

OBJECTIVES/HYPOTHESIS

To explore the clinically feasible diagnosis criteria and treatment outcomes of allergy-related sialodochitis (ARS).

STUDY DESIGN

Prospective Cohort Study.

METHODS

Ninety-six consecutive patients were enrolled by the following criteria: 1) recurrent swelling of ≥2 large salivary glands that lasted for ≥3 months; 2) with mucus plug exudations; 3) with atopic diseases; 4) ductal stenosis and/or ectasia. Sixty-four patients with elevation of peripheral blood eosinophil (PBE) and/or serum IgE level comprised group A (highly-suspected ARS group), while the remaining 32 comprised group B (patients without confirmed evidence of ARS). These patients were treated with interventional endoscopy. A chronic obstructive sialadenitis symptom (COSS) questionnaire was used to quantify the treatment outcomes.

RESULTS

In group A, Serum IgE was elevated in 84.4% of patients and PBE was elevated in 34.4% of patients. Percentage of submandibular gland involvement was higher in group A than group B (48.4% vs. 18.8%). On sialograms, the snowflake changes of branch ducts were seen in higher percentage of group A compared with group B (59% vs. 35% for parotid glands, 27% vs. 8% for submandibular glands, respectively). Mucus plug smears showed abundant eosinophils in 14 group A patients. Biopsy of five group A patients revealed significant eosinophil infiltration around the main and interlobular ducts. During follow-up, the COSS scores were significantly decreased in both groups, and group B was improved better than group A.

CONCLUSION

PBE and serum IgE are important diagnostic indexes of ARS. Mucus plug smear or histopathology verifies the diagnosis. Interventional endoscopy is helpful for ARS cases.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:2030-2035, 2021.

Eosinophilic sialodochitis: An emerging atopic condition

OBJECTIVE

To report the clinical characteristics of the largest single centre cohort of patients with eosinophilic sialodochitis.

METHODS

Analysis of data relating to 37 patients seen in a dedicated multidisciplinary clinic was performed. Demographic, clinical, haematological, cytological, histological and radiological features were collated. Response to trials of allergy treatment was assessed.

RESULTS

Thirty-seven patients (30 female, seven male) were identified, 42% of whom were of Afro-Caribbean origin, with a mean age of 50.4 years (range 28-80 years). Mean symptom duration at presentation was 10 years (range 2-33 years). Parotid and submandibular gland involvement was equally reported. The most commonly reported symptoms were swelling (97%), itching of the overlying skin (92%), salivary gland discomfort (84%) and "string-like" mucus discharge from salivary duct orifices (76%). Twenty-three patients (62%) demonstrated atopic disease and serum IgE level elevated in 57%. All 37 patients had eosinophils present in aspirated duct contents samples while raised peripheral eosinophil count was seen in 41%. Anecdotal symptom improvement was reported with antihistamine, antileukotriene or steroid treatment.

CONCLUSION

Eosinophilic sialodochitis should be considered in any patient presenting with recurrent salivary gland swelling. Further studies are needed to evaluate treatments directed at a likely allergic pathogenesis.

Benralizumab effect on severe chronic rhinosinusitis with nasal polyps (CRSwNP): A randomized double-blind placebo-controlled trial

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) can be a severe and debilitating disease associated with significant morbidity, loss of smell, sinus pressure and asthma exacerbations. Eosinophils play a role in the majority (85%) of patients. Benralizumab, an afucosylated monoclonal antibody directed against the IL-5 receptor, has powerful apoptotic effects on eosinophils.

OBJECTIVE

We sought to investigate the therapeutic benefit of inhibiting the IL-5 receptor using benralizumab to treat severe rhinosinusitis with nasal polyps.

METHODS

Patients with severe NP (defined by endoscopic grade 5 or more out of 8) with elevated eosinophils and a history of previous surgical or endoscopic polypectomy met entry criteria and were randomized in a double-blind fashion to receive 30 mg benralizumab SC or placebo. Endoscopic NP score was assessed at baseline and at treatment week 20. CT scan, SNOT-22 survey and UPSIT smell test score changes were also evaluated.

RESULTS

Thirty-three patients were screened, and twenty-four (n = 24) were enrolled in the study. Compared with baseline, benralizumab significantly improved NP score (-0.9 ± 0.2, P = 0.004) whereas placebo did not (-0.3 ± 0.3, P = 0.166). Benralizumab induced polyp size reduction compared with placebo did not reach statistical significance (P = 0.103). Five of 12 benralizumab-treated patients (42%) had improvements in all major outcomes (polyp score, CT, SNOT-22 and smell test) versus 2 out of 12 placebo (17%). The ratio of blood eosinophil count to allergen skin test positivity correlated with polyp reduction.

CONCLUSION

Benralizumab was well-tolerated and compared with baseline achieved a statistically significant reduction in nasal polyp size, sinus occupancy, symptoms and improved sensation of smell for most patients (83%).

Sialodochitis fibrinosa managed with staged bilateral total parotidectomy

OBJECTIVE

This paper reports a rare case of a 61-year-old man with sialodochitis fibrinosa.

METHODS

Clinical case report and review of current literature.

RESULTS

Sialodochitis fibrinosa is a diagnosis of exclusion and in many cases can be managed conservatively. Conservative management failed for this patient and he was managed successfully with staged bilateral total parotidectomy.

CONCLUSION

Sialodochitis fibrinosa should be considered as a differential diagnosis of painful bilateral facial swelling. While conservative management is successful for many patients, staged bilateral total parotidectomy may be necessary for full remission of symptoms; the timing of this is crucial to reduce the risk of facial nerve palsy.

Eosinophilic Sialodochitis: A Type of Chronic Obstructive Sialadenitis Related to Allergy

OBJECTIVES

To investigate the clinical, laboratory, radiological, histopathological, and immunohistochemical features, and the expression of allergy-related cytokines in eosinophilic sialodochitis (ES).

METHODS

Thirty-eight patients diagnosed with chronic obstructive sialadenitis (COS) who had undergone glandular excision or incisional biopsy were enrolled. Seventeen patients with comorbid atopic disease and increased ductal tissue eosinophils comprised the ES group, while 21 patients comprised the COS group. The clinicopathological features and allergy-related cytokine expression were compared between groups.

RESULTS

The ES group frequently involved multiple, bilateral major salivary glands, and the number of glands was significantly greater than the COS group (2.8 ± 1.1 vs. 1.2 ± 0.4, P < .001). Serum immunoglobulin (Ig) E was elevated in 91% of patients in ES group (419 ± 357 kU/L) and peripheral blood eosinophil was significantly greater compared with the COS group (7.6% ± 4.6% vs. 2.5% ± 1.4%, P < .001). Histologically, eosinophil infiltration in ES group was observed around the main and interlobular ducts (50 ± 39/high power field [HPF]). Follicular hyperplasia (76%), epithelial mucous metaplasia (82%), and mucus plugs with eosinophils (41%) were observed. IgE-positive cell count was 20.7 ± 18.3/HPF and tryptase-positive mast cell count was 23.5 ± 15.1/HPF, which was significantly greater than the respective cell counts in COS group, which mainly infiltrated around the ducts. The levels of interleukin-4, interleukin-13, and eotaxin in tissue were significantly greater in ES than the COS group.

CONCLUSIONS

The clinicopathological characteristics of ES are significantly different from COS and ES might have an allergy-related pathogenesis.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E800-E806, 2021.

CT and MR imaging findings of non-neoplastic cystic lesions of the parotid gland

A variety of neoplastic and non-neoplastic lesions of the parotid gland can present with a predominantly cystic architecture, and although radiologists frequently encounter cystic parotid tumors, other non-neoplastic lesions should also be included in the differential diagnoses of cystic parotid lesions. Non-neoplastic cystic lesions are usually classified as either congenital/acquired cystic lesions or inflammatory/infectious lesions. Adequate knowledge about these rare conditions is essential for appropriate diagnosis and optimal treatment strategy. This review article describes CT and MR imaging features of non-neoplastic cystic lesions of the parotid gland and provides helpful suggestions on the differential diagnoses for cystic parotid lesions.