Allergy-Related Sialodochitis: A Preliminary Cohort Study

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.

Symptom Outcomes After Sialendoscopy-Assisted Salivary Duct Surgery: A Prospective 6-Year Study

OBJECTIVE

The objective is to evaluate the long-term impact of sialendoscopic-assisted salivary duct surgery (SASDS) on sialadenitis symptoms using the Chronic Obstructive Sialadenitis Symptoms (COSS) questionnaire.

METHODS

The COSS questionnaire, which scores symptoms on a 0-100 scale, was administered prospectively to adult patients pre-operatively, 1-year, and 6-years post-operatively. We examined COSS scores and categories representing complete (<10), partial (10-25), and no (>25) resolution of symptoms with attention to factors significantly associated with incomplete resolution (≥10).

RESULTS

Approximately 6-years after SASDS, 111 patients reported scores for 128 symptomatic glands (72 with sialolithiasis, 56 without sialolithiasis). For glands with sialolithiasis, the median COSS score pre-SASDS was 27.5 (interquartile range [IQR]: 13.5-43), which was significantly reduced to 1.0 (IQR: 0-5.5) at 1-year and 1.5 (IQR 0-5) at 6-years postoperatively. Glands without sialolithiasis had a median COSS score of 40.5 (IQR: 23-52.5) preoperatively, that significantly reduced to 13.5 (IQR 5-21) at 1-year and 14 (IQR 6.5-25.5) at 6-years post-operatively. There was no significant difference in scores from 1- to 6-years. Intraoperative presence of sialolith, absence of stenosis, stenosis in the distal duct, and submandibular gland involvement were significant predictors of complete resolution of symptoms at 6-years.

CONCLUSION

Approximately 6-years after SASDS for sialadenitis, the majority of patients have durable symptom improvement. The sialolithiasis group had higher rates of complete resolution compared to the non-sialolithiasis group. Presence of ductal stenosis on sialendoscopy, non-distal stenoses, and parotid gland involvement were risk factors for persistent long-term sialadenitis symptoms. Laryngoscope, 133:792-800, 2023.

[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.

Differences between radioactive iodine-induced sialadenitis and chronic obstructive parotitis

The purpose of this study was to clarify the differences in the diagnosis and treatment outcomes between radioactive iodine-induced sialadenitis (RAIS) and chronic obstructive parotitis (COP). The study cohort comprised 47 consecutive patients diagnosed with RAIS and 50 patients with COP. All patients were treated by interventional endoscopy. Clinical, sialography, and endoscopy characteristics and treatment outcomes were compared between the two groups. Compared with the COP group, the RAIS group included more females (male:female ratio 1:8.4 vs 1:2.1; P = 0.011) and had a younger onset age (42 vs 50 years; P = 0.001) and shorter disease duration prior to hospital visit (5.4 vs 34.8 months; P < 0.001). In the RAIS group, sialography revealed obliteration of the main duct (20.4% vs 0%; P < 0.001), non-visualization of the main gland (23.7% vs 0%; P < 0.001), and incomplete contrast filling of the main gland (19.4% vs 6.4%; P = 0.008), which were scarcely observed in the COP group. Endoscopy revealed a higher percentage of duct atresia in RAIS compared to COP (20.4% vs 0%; P < 0.001). During follow-up, a higher percentage of RAIS patients had duct atresia and gland atrophy (49.5% vs 1.1%, P < 0.001). Compared with COP, RAIS more commonly involves younger females and has a shorter disease duration. Atresia of the main duct and atrophy of the gland parenchyma occur more often despite the use of interventional endoscopy.