Primary Thyroid Lymphoma: Clinical Factors Predicting the Possibility of Diffuse Large B-Cell Lymphoma.

Aims: Among primary thyroid lymphomas (PTLs), diffuse large B-cell lymphoma (DLBCL) has a poorer prognosis than other indolent lymphomas such as mucosa-associated lymphoid tissue (MALT) or follicular lymphoma (FL). However, the clinical differences between DLBCL and indolent lymphoma remain unclear. Therefore, this retrospective study on PTL was aimed at investigating the clinical differences between DLBCL and indolent lymphomas and identifying the factors differentiating DLBCL from indolent lymphomas. Materials and Methods: Medical records of 28 patients diagnosed with PTL and treated at our institution between 2005 and 2022 were retrospectively analyzed. Data on the following clinical variables were extracted: sex, age, symptoms (pain and dysphagia), ultrasonographic appearance patterns, the presence of airway stenosis on computed tomography and laryngeal endoscopy, blood test results, disease stage, and pathological diagnosis. Results: In all, 13 patients were histologically diagnosed with DLBCL, 12 with MALT lymphoma, and 3 with FL. Significant differences in disease-specific survival rates were evident between the DLBCL and indolent lymphoma groups (68.2 vs 100%, P = .043). High lactate dehydrogenase levels (>230 U/mL) and airway stenosis were observed only in patients with DLBCL. Multivariate analysis identified that the presence of a linear echoic strand pattern and the absence of an echoic nodular pattern on ultrasound were independently associated with DLBCL (P = .0497 and .012, respectively). Conclusion: DLBCL can cause airway stenosis. The linear echogenic strand pattern and the absence of a nodular pattern should be recognized as predictive factors of DLBCL.

The fine-needle aspiration cytology and clinical findings of Kikuchi-Fujimoto disease in pediatric patients: a retrospective clinical study.

BACKGROUND: Histological evaluation of lymph node is crucial for the definitive diagnosis of Kikuchi-Fujimoto disease (KFD). However, lymph node biopsy under local anesthesia is often difficult in pediatric patients. OBJECTIVES: We evaluated cytological findings for pediatric patients with prolonged cervical lymphadenitis clinically suggestive of KFD and investigated the clinical characteristics of patients diagnosed with KFD by fine-needle aspiration cytology (FNAC). METHODS: This retrospective clinical study included 58 Japanese pediatric patients with cervical lymphadenitis who underwent FNAC. RESULTS: Cytological diagnosis was KFD for 22 and suspicion of KFD for 11 patients. The remaining 25 patients were diagnosed with non-specific lymphadenitis (NSL). Tenderness was independently associated with a higher frequency of both KFD in narrow and broad senses, compared with NSL (p = .009; p = .038). The percentage of patients who underwent FNAC within 28 days from symptom onset tended to be higher among patients with KFD in a narrow sense than those with NSL (p = .052). CONCLUSION: This study indicated that the period from symptom onset to FNAC (<28 days) and the symptom of tenderness were associated with the cytological diagnosis of KFD.

Clinicopathologic Analysis of Sinonasal Inverted Papilloma, with Focus on Human Papillomavirus Infection Status.

Sinonasal inverted papilloma (SNIP) can recur; however, the factors related to tumor recurrence remain unclear. This study aimed to analyze risk factors, including human papillomavirus (HPV) infection, as well as other factors associated with SNIP recurrence. Thirty-two patients who were diagnosed with SNIP and underwent surgery between 2010 and 2019 were enrolled: 24 men and 8 women, with a mean age of 59.2 years. The mean follow-up was 57.3 months. Demographics and information about history of smoking, diabetes mellitus (DM), hypertension, allergic rhinitis, alcohol consumption, tumor stage, surgical approach, and recurrence were reviewed retrospectively. Specimens were investigated using polymerase chain reaction to detect HPV DNA (high-risk subtypes: 16, 18, 31, 33, 35, 52b, and 58; low-risk subtypes: 6 and 11). Seven patients (21.9%) experienced recurrence. HPV DNA was detected in five (15.6%) patients (high-risk subtypes, n = 2; low-risk subtypes, n = 3). Patients with recurrence of SNIP had a higher proportion of young adults and displayed higher rates of HPV infection, DM, and advanced tumor stage than those without recurrence. HPV infection, young adulthood, DM, and advanced tumor stage could be associated with a high recurrence rate, which suggests that patients with these risk factors could require close follow-up after surgery.

Application of Lip Biopsy for the Histological Diagnosis of Immunoglobulin G4-Related Disease.

We describe the case of a 51-year-old woman with immunoglobulin G4-related disease (IgG4-RD) diagnosed using lip biopsy. She reported having bilateral submandibular nodules for a month. Magnetic resonance imaging showed diffuse swelling in the bilateral submandibular glands (SMGs), suggesting inflammatory changes. Laboratory data revealed an elevated level of serum IgG4. Fine needle aspiration cytology of the SMG showed a considerable number of lymphocytes with degeneration but did not demonstrate specific findings for a definitive diagnosis of IgG4-RD. Lip biopsy was performed, and a biopsy specimen from the labial salivary gland showed abundant lymphoplasmacytic infiltration with a large number of IgG4-positive cells. The patient was diagnosed with IgG4-RD based on histological and laboratory findings. Findings of further examinations revealed that the patient had autoimmune pancreatitis, confirming our diagnosis. Four months after prednisolone administration, improvement of the submandibular and pancreatic lesions was observed. One year after the initial presentation, the serum IgG4 level was normalized. In cases of IgG4-RD with salivary gland involvement, lip biopsy might be one of the options for the histological diagnosis of IgG4-RD.

Methotrexate-Associated Lymphoproliferative Disorders Mimicking Granulomatosis With Polyangiitis: A Radiological Diagnostic Challenge.

Methotrexate-associated lymphoproliferative disorders (MTX-LPD) frequently involve the extranodal organs throughout the body. Among the extranodal occurrences of MTX-LPD, pulmonary involvement is most frequent. In contrast, there are only a few reports of MTX-LPD in the nasal cavity or paranasal sinuses. Moreover, there are no previous reports of MTX-LPD mimicking granulomatosis with polyangiitis (GPA) in imaging examinations. We describe a case of a 53-year-old woman with MTX-LPD mimicking GPA in the nasal cavity and lungs. She complained of left nasal obstruction and discharge, general fatigue, and continual fever for 2 months. The patient had been diagnosed with rheumatoid arthritis and received methotrexate (MTX) for over 10 years. Contrast-enhanced computed tomography revealed unenhanced masses in the nasal cavity and multiple masses with cavitary changes in the bilateral lungs, suggesting GPA. However, histological examination of the nasal lesion and a history of MTX treatment indicated a diffuse large B-cell lymphoma type MTX-LPD. Two weeks after MTX withdrawal, prominent improvements in both lesions were observed. Complete regression of the nasal lesion was observed 3 months after discontinuation of MTX. Thus, MTX-LPD may mimic GPA in imaging examinations.

Cytopathological Findings of Secretory Carcinoma of the Salivary Gland and the Diagnostic Utility of Giemsa Staining.

Secretory carcinoma is a salivary gland neoplasm first described as a mammary analogue secretory carcinoma by Skalova and redesignated as a secretory carcinoma in the 2017 World Health Organization Classification of Head and Neck Tumors. Secretory carcinoma diagnosis is reliant on specific cytological and histological findings and the detection of an ETV6-NTRK3 fusion gene. Here, we examined the clinical and cytopathological features of four cases of secretory carcinoma occurring in three males and a female, aged between 39 and 74 years. All four tumors involved the parotid gland, and were found to have the ETV6-NTRK3 fusion gene. Fine-needle aspiration-based cytology smears of all tumors displayed papillary and/or dendritic pattern clusters, some of which were associated with blood vessels. The neoplastic cells displayed enlarged nuclei with fine chromatin and small, distinct, single nucleoli. Furthermore, several neoplastic cells with a characteristic vacuolated cytoplasm were identified in each specimen. Giemsa staining revealed cytoplasmic vacuolation, intracytoplasmic metachromatic secretions and/or various sized metachromatic granules, and a background of metachromatic mucin in all four specimens. Given this, we conclude that these cytological findings, especially those of the Giemsa staining, might be helpful in the diagnosis of secretory carcinoma.

PD-L1 expression in tongue squamous cell carcinoma.

PURPOSE: Immune checkpoint proteins programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) are important therapeutic targets for head and neck cancer. This large-scale case study aimed to analyze tongue squamous cell carcinomas (SCCs) and evaluate the correlation between PD-L1 expression and clinical prognosis. So far, this study is the largest case study on PD-L1 expression in tongue SCCs. METHODS: This is a case-control study that analyzed 121 tongue SCCs. Paraffin-embedded sections and clinical data were obtained retrospectively and immunohistochemistry with PD-L1 was performed. RESULTS: 11.6% contained ≥ 50% of PD-L1-positive cells, 57.1% of these cases had a poor prognosis with nodal metastasis. Among cases of T1/2 primary lesions with nodal metastasis, cases of high PD-L1 expression had a significantly shorter disease-free survival than cases of no PD-L1 expression (p = 0.018). The hazard ratio for high PD-L1 expression was 3.21 (95 per cent CI, 1.26-8.72) compared with no PD-L1 expression after adjusting for other factors. CONCLUSIONS: These data indicate that PD-L1 upregulation in tongue SCCs is associated with a more advanced stage and shorter disease-free survival. PD-1/PD-L1 inhibitors might hence constitute potential adjuvant therapy for tongue SCCs with PD-L1 upregulation.

Supraglottic subepithelial benign mass lesions: Focus on clinical features of sialolipoma-like lesion.

OBJECTIVES: Sialolipoma has been classified as a benign soft tissue lesion in the 2017 World Health Organization classification of head and neck tumors. To our knowledge, only one case of laryngeal sialolipoma has been reported in the English literature. We conducted a retrospective study to identify clinical characteristics of supraglottic sialolipoma-like lesion and differentiate it from other supraglottic subepithelial masses. METHODS: Medical records of 16 patients with supraglottic subepithelial benign mass lesions who underwent histological evaluation between 2003 and 2019 were retrospectively analyzed. Sialolipoma-like lesion was defined as a local finding of a well-circumscribed gross mass with pathological presence of salivary gland-like parenchymal lobules with evenly interspersed adipose tissue. RESULTS: Eight patients showed histological positivity for sialolipoma-like lesion, 3 for amyloidosis, 2 for hemangioma, and 1 each for cyst, lymphoid hyperplasia, and chondrometaplasia. Sialolipoma-like lesion tended to be predominant among men; those affected had a mean age of 52.8 (range, 39-74) years. By contrast, among patients with amyloidosis, the ratio of men to women was 1:2 (100% vs. 33%; p = 0.055). Fiberscopic examination of all patients with sialolipoma-like lesions identified well-circumscribed, yellowish masses, closely resembling local amyloidosis findings. Sialolipoma-like lesion was associated with a significantly higher body-mass index (BMI; 27.4 ± 2.8 kg/m2) than amyloidosis (21.6 ± 1.4 kg/m2; p = 0.014). The transoral approach was used for lesion resection in all patients with sialolipoma-like lesion. No patient experienced postoperative recurrence. CONCLUSION: Laryngeal sialolipoma-like lesion might be more prevalent than was previously reported, and histological examination is important to differentiate it from amyloidosis. Supraglottic sialolipoma-like lesion must be differentially diagnosed in patients with high BMI presenting with well-circumscribed, yellowish supraglottic masses.

Basal Cell Carcinoma in the Middle Ear: A Case Report and Literature Review.

Although basal cell carcinoma (BCC) often occurs in the head and neck region, BCC in the middle ear is extremely rare. As far as we could determine, only five cases of BCC in the middle ear have been reported previously in the literature. We present the case of a 54-year-old Japanese man with BCC in the middle ear. Preoperative histopathologic examination indicated the possibility of skin appendage tumor. Mastoidectomy and extirpation of the lesion were performed, and the resected tumor was finally diagnosed as BCC. Four months after the initial surgery, the patient had local recurrence and reoperation, and postoperative radiotherapy was given. The patient had repeat local recurrence in the parapharyngeal space 3 years and 2 months following postoperative radiotherapy. The patient did not respond to two courses of chemotherapy with cisplatin and 5-fluorouracil, and eventually died of the primary disease 4 years and 7 months after the initial surgical treatment. We reviewed the five cases previously reported in the literature concerning BCC in the middle ear. More case reports concerning BCC in the middle ear are needed to determine its appropriate management.

Clinicopathological analysis of 34 Japanese patients with EBV-positive mucocutaneous ulcer.

Epstein-Barr virus (EBV)-positive mucocutaneous ulcer (EBVMCU) is a unifocal mucosal or cutaneous ulcer that is histologically characterized by proliferating EBV-positive atypical B cells. While EBVMCU demonstrates a histology similar to that of EBV-positive diffuse large B-cell lymphoma (DLBCL), their clinical behavior differs. Thus, characterizing distinguishing features of EBVMCU and EBV-positive DLBCL is critical. To identify unique characteristics between EBVMCU and lymphoma, we analyzed the clinicopathological and genetic features of 34 Japanese patients with EBVMCU and compared them to those of 24 EBV-positive DLBCL patients and 25 EBV-negative DLBCL patients. All patients with EBVMCU had localized ulcerative lesions, and 31 patients (91%) were using immunosuppressants, such as methotrexate (MTX) or hydroxycarbamide. All patients that were followed up with exhibited good prognosis following immunosuppressant reduction or chemotherapy. In addition, 17 EBV-positive DLBCL patients, and 15 EBV-negative DLBCL patients, received chemotherapy (P < 0.001, P < 0.001, respectively). Our data showed that EBVMCU did not increase indicators associated with lymphoma prognosis, such as soluble interleukin 2 receptor (sIL-2R) and lactate dehydrogenase (LDH) compared to those in the EBV-positive DLBCL or EBV-negative DLBCL groups (sIL-2R, P < 0.001, P = 0.025; LDH, P = 0.018, P = 0.038, respectively). However, histologically, EBVMCU exhibited EBV-positive, variable-sized, atypical B-cell proliferation. Thus, EBVMCU was histologically classified as: (1) polymorphous; (2) large cell-rich; (3) classic Hodgkin lymphoma-like; and (4) mucosa-associated lymphoid tissue lymphoma-like. Moreover, genetic analysis showed that immunoglobin heavy chain (IGH) gene rearrangement did not differ significantly between EBVMCU and EBV-positive DLBCL (44% vs. 32%; P = 0.377), or between EBVMCU and EBV-negative DLBCL (44% vs. 58%; P = 0.280). Therefore, it is difficult to distinguish EBVMCU from EBV-positive DLBCL using only pathological and genetic findings, suggesting that clinical information is important in accurately distinguishing between EBVMCU and EBV-positive DLBCL.

Clinical characteristics of subglottic cancer: emphasis on therapeutic management strategies for stage II subglottic cancer.

Background: Subglottic cancer (SGC) is extremely rare, as most laryngeal cancers are localized to the glottic region. Accordingly, the clinical characteristics of SGC have not been well characterized.Objectives: In the current study, SGCs were clinically evaluated, and the outcomes of radiotherapy (RT) in patients with stage II SGC were assessed.Materials and Methods: Medical data derived from 11 patients with SGC, who were treated at our hospital between 1995 and 2019, were retrospectively reviewed.Results: In our department SGC accounted for 3.9% of the 280 laryngeal cancer patients treated during the study period. At the time of SGC diagnosis, 9 (81.8%) had stage II cancer, 1 had stage III cancer, and 1 had stage IV cancer. Stage II SGC patients treated with concurrent chemoradiotherapy (CCRT) showed a significantly higher local control rate (p = .026) and laryngeal dysfunction free rate (p = .026) than those treated with RT alone. Salvage surgery, performed in 4 patients whose disease was not locally controlled with CCRT/RT, was successful in 3 patients.Conclusion: As a treatment strategy for stage II SGC, CCRT is an acceptable initial treatment for laryngeal function and preservation while salvage surgery is effective for recurrence after CCRT/RT treatment.

Pathological evaluation of radiotherapy and concomitant intraarterial cisplatin for maxillary sinus cancer.

OBJECTIVE: Since 2010, we have mainly performed surgical treatment following radiotherapy and concomitant intraarterial cisplatin (RADPLAT) for locally advanced maxillary sinus cancer (MSC). The present study investigated treatment results and pathological evaluations following RADPLAT for MSC. METHODS: Pathological response to RADPLAT was evaluated using surgical specimens. Pathological response was graded in accordance with the classification method that Shimosato reported in 1964, as grade V (no tumor cells remain in any of section), grade IV, III, II, I, and 0. Five-year overall and disease-specific survival rates were estimated using Kaplan-Meier methods. Univariate analyses of correlations between recurrence of MSC and other clinicopathological parameters were evaluated using the chi-square or Fisher's exact tests. RESULT: 19 patients were enrolled in this study, 5 patients showed T3 disease and 14 had T4 disease. One patient demonstrated local recurrence and 3 patients experienced distant metastasis. The 5-year overall survival rate was 67.1% (T3, 50.0%; T4, 69.6%), and the 5-year disease-specific survival rate was 81.9% (T3, 100%; T4, 76.0%). Histological response was categorized as grade V in 9 cases. No significant risk factors for residual cancer were identified. CONCLUSION: Our study suggested that RADPLAT not only has a low risk of side effects, but also could represent an effective procedure for locally advanced MSC by pathological evaluation. Increasing the therapeutic intensity of RADPLAT might provide an effective modality to avoid highly invasive surgery.

Clinical Significance of Cytoplasmic IgE-Positive Mast Cells in Eosinophilic Chronic Rhinosinusitis.

Cross-linking of antigen-specific IgE bound to the high-affinity IgE receptor (FcεRI) on the surface of mast cells with multivalent antigens results in the release of mediators and development of type 2 inflammation. FcεRI expression and IgE synthesis are, therefore, critical for type 2 inflammatory disease development. In an attempt to clarify the relationship between eosinophilic chronic rhinosinusitis (ECRS) and mast cell infiltration, we analyzed mast cell infiltration at lesion sites and determined its clinical significance. Mast cells are positive for c-kit, and IgE in uncinated tissues (UT) and nasal polyps (NP) were examined by immunohistochemistry. The number of positive cells and clinicopathological factors were analyzed. Patients with ECRS exhibited high levels of total IgE serum levels and elevated peripheral blood eosinophil ratios. As a result, the number of mast cells with membranes positive for c-kit and IgE increased significantly in lesions forming NP. Therefore, we classified IgE-positive mast cells into two groups: membrane IgE-positive cells and cytoplasmic IgE-positive cells. The amount of membrane IgE-positive mast cells was significantly increased in moderate ECRS. A positive correlation was found between the membrane IgE-positive cells and the radiological severity score, the ratio of eosinophils, and the total serum IgE level. The number of cytoplasmic IgE-positive mast cells was significantly increased in moderate and severe ECRS. A positive correlation was observed between the cytoplasmic IgE-positive cells and the radiological severity score, the ratio of eosinophils in the blood, and the total IgE level. These results suggest that the process of mast cell internalization of antigens via the IgE receptor is involved in ECRS pathogenesis.

MACC1 expression is an indicator of recurrence in early-stage glottic cancer.

BACKGROUND: Metastasis-associated in colon cancer 1 (MACC1) has been reported to be an independent indicator of poor prognoses in some kinds of cancer due to disease metastasis or recurrence. We investigated the correlation between MACC1 expression and the prognosis of glottic cancer. METHODS: Paraffin-embedded, early-stage (I or II) glottic cancer specimens (n = 52) were immunohistochemically analyzed to explore MACC1 expression. The clinical records associated with each case were also examined. Recurrence-free survival (RFS) was estimated using the Kaplan-Meier method, and between-group RFS differences were assessed using the log-rank test. The multivariate analyses were evaluated using the Cox's proportional-hazard model. RESULTS: Patients were treated with only radiotherapy (RT) (n = 37, including 18 with T1 disease and 19 with T2 disease), or with chemoradiotherapy (CRT) (n = 15, including 1 with T1 disease and 14 with T2 disease). Eleven patients demonstrated local recurrence and two patients experienced cervical lymph node recurrence. Tumor specimens were MACC1-positive in 9 of the 13 (69.2%) patients with local or neck recurrence, and 7 of the 11 (63.6%) patients with local recurrence. The RFS rate of patients who were treated with only RT was significantly lower than that of patients who were treated with CRT (P = 0.0243). The RFS rate was significantly lower in cases with MACC1 expression than in those without MACC1 expression (P = 0.0003). Multivariate analysis revealed that MACC1 expression was an independent risk factor of local recurrence (P = 0.0016). CONCLUSION: MACC1 is an independent indicator of recurrence related to RFS in early-stage glottic cancer.

Role of Macrophage Migration Inhibitory Factor in NLRP3 Inflammasome Expression in Otitis Media.

HYPOTHESIS: Macrophage migration inhibitory factor plays an important role in the expression of interleukin (IL)-1ß and the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in lipopolysaccharide-induced otitis media. BACKGROUND: NLRP3 inflammasome and macrophage migration inhibitory factor are critical molecules mediating inflammation. However, the interaction between the NLRP3 inflammasome and macrophage migration inhibitory factor has not been fully examined. METHODS: Wild-type mice and macrophage migration inhibitory factor gene-deficient (MIF) mice received a transtympanic injection of either lipopolysaccharide or phosphate-buffered saline. The mice were sacrificed 24 hours after the injection. Concentrations of IL-1ß, NLRP3, ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain and a pyrin domain), and caspase-1 in the middle ear effusions were measured by enzyme-linked immunosorbent assay. Temporal bones were processed for histologic examination and immunohistochemistry. RESULTS: In the immunohistochemical study using the wild-type mice, positive staining of macrophage migration inhibitory factor, NLRP3, ASC, and caspase-1 were observed in infiltrating inflammatory cells induced by lipopolysaccharide in the middle ear. The number of inflammatory cells caused by lipopolysaccharide administration decreased remarkably in the MIF mice as compared with the wild-type mice. The concentrations of IL-1ß, NLRP3, ASC, and caspase-1 increased in the lipopolysaccharide-treated wild-type mice. The MIF mice with lipopolysaccharide had decreased levels of IL-1ß, NLRP3, ASC, and caspase-1 as compared with the wild-type mice. CONCLUSION: Macrophage migration inhibitory factor has an important role in the production of IL-1ß and the NLRP3 inflammasome. Controlling the inflammation by modulating macrophage migration inhibitory factor and the NLRP3 inflammasome may be a novel therapeutic strategy for otitis media.

Long-term treatment with clarithromycin and carbocisteine improves lung function in chronic cough patients with chronic rhinosinusitis.

PURPOSE: Chronic cough is a common complaint. Because the pathophysiology of chronic cough is complicated, the management of chronic cough is challenging. To the best of our knowledge, no previous study has examined the effect of macrolide antibiotics in chronic cough patients with chronic rhinosinusitis. The purpose of this study is to determine the changes in lung function for chronic cough patients with chronic rhinosinusitis who are treated by clarithromycin and carbocisteine. MATERIALS AND METHODS: Thirty-two chronic cough patients with chronic rhinosinusitis were recruited. Patients using inhaled corticosteroids and/or a bronchodilator, asthmatic patients, and patients with abnormal findings on auscultation and/or chest X-ray examination were excluded from this study. The patients received low-dose clarithromycin treatment for 3 months. Both before and after the treatment, a computed tomography (CT) scan of the paranasal sinuses, lung function test, peripheral blood test, and sino-nasal outcome test (SNOT-20) were applied. RESULTS: Both the lung function and Lund-MacKay CT scores were improved by the long-duration therapy with macrolide antibiotics. The change in obstructive pulmonary function and the improvement of the CT score in each subject were significantly correlated. SNOT scores also improved after the treatment. CONCLUSIONS: The macrolide antibiotics treatment has beneficial effects on lung function in non-asthmatic chronic cough patients with normal chest X-ray findings. The improvement of chronic rhinosinusitis may have some role in the lung condition. Upper respiratory tract examination and treatment may be useful for the management of chronic cough.

The efficacy of OK-432 sclerotherapy on thyroglossal duct cyst and the influence on a subsequent surgical procedure.

Background: Although there are studies regarding the efficacy of OK-432 sclerotherapy on thyroglossal duct cyst (TDC), its effects on surgical procedure following this therapy have not been properly described. Objectives: The present study aimed to delineate the prognostic factors of OK-432 sclerotherapy in patients with TDC and investigate its influence on subsequent surgical procedure and the histological characteristics in patients with poor response to OK-432 sclerotherapy. Material and methods: We conducted a retrospective analysis of the medical records of 20 TDC patients treated with OK-432 sclerotherapy. Results: Of the 20 patients, OK-432 sclerotherapy was effective in 5 patients (25.0%). OK-432 showed a lower effective rate in multilocular cysts (9.1%) than in unilocular cysts (44.4%), although not significantly. Five cases were treated with surgery following OK-432 sclerotherapy. There was no significant difference in the operating time and the amount of bleeding between patients with and without OK-432 sclerotherapy. From the results of the histological examination of the cyst wall, two cases had stratified squamous epithelium and two cases showed the absence of lymphocyte infiltration. Conclusion and significance: OK-432 sclerotherapy is an acceptable initial treatment for TDC, especially in unilocular cysts, because of lack of influence on surgical procedure.