Sublingual immunotherapy (SLIT) is an effective and popular treatment for cedar pollinosis. Although SLIT can cause allergic side effects, eosinophilic esophagitis (EoE) is a lesser-known side effect of SLIT. A 26-year-old male with cedar pollinosis, wheat-dependent exercise-induced anaphylaxis, and food allergies to bananas and avocados presented with persistent throat itching, difficulty swallowing, heartburn, and anterior chest pain 8 days after starting SLIT for cedar pollinosis. Laboratory examination showed remarkably elevated eosinophils, and esophagogastroduodenoscopy revealed linear furrows in the entire esophagus. Histological examination of an esophageal biopsy specimen revealed high eosinophil levels. The patient was strongly suspected with EoE triggered by SLIT. The patient was advised to switch from the swallow to the spit method for SLIT, and the symptoms associated with SLIT-triggered EoE were reduced after switching to the spit method. This case highlights the importance of recognizing SLIT-triggered EoE as a potential side effect of SLIT for cedar pollinosis, especially with the increasing use of SLIT in clinical practice. EoE can occur within a month after initiating SLIT in patients with multiple allergic conditions, as observed in our case. Furthermore, the spit method should be recommended for patients who experience SLIT-triggered EoE before discontinuing SLIT.

An 83-year-old man suddenly lost consciousness, and his blood pressure dropped. Results of blood analysis were within normal range. A chest radiograph showed enlargement of the left mediastinum. Computed tomographic scan of the chest showed a large mass surrounding the left common carotid artery in the left upper mediastinum. Histology revealed a large B-cell lymphoma. A Holter ECG showed transient sinus bradycardia and atrioventricular block. The power spectrum revealed increase in power of high frequency, suggesting that general vagal activity might be related to bradycardia. Evaluation of autonomic system from high frequency and low frequency components may be useful in examining the mechanisms of sudden bradycardia and/or hypotension of unknown origin.

Sclerosing mucoepidermoid carcinoma (SMC) is described as a "sclerosing variant" of mucoepidermoid carcinoma, and it is characterized by dense fibrosis and sclerosis of the stroma. SMC with eosinophilia (SMCE) is another and more rare subtype characterized by eosinophilia in addition to the sclerotic stroma common to SMC. However, unlike SMC, SMCE is not listed in the current 4th edition of WHO classification. Here, we describe three cases: one SMC in the parotid gland, one SMCE in the submandibular gland and one SMCE in the minor salivary gland of the oral cavity. The patients included a 71-year-old Japanese male, a 74-year-old Japanese female, and an 81-year-old Japanese female. They each complained of mass formation and underwent surgical resection. Histologically, the tumors mainly consisted of squamous cells with scarce keratinization that formed irregular large and small nests along with cystic structures containing mucous cells against the background of sclerotic stroma. One oral SMCE showed fine nesting and trabecular invasion. The two SMCEs included dense aggregates of eosinophils as well as more prominent lymphoid infiltration. Fluorescence in situ hybridization for MAML2 confirmed split signals in SMC, but not in SMCE.

Gene profiling has identified at least 4 breast cancer subtypes, including Luminal A, Luminal B, HER2-enriched and basal-like, and immunohistochemistry is used as a guide to determine these subtypes. In the present study, patients with ER-positive, HER2-negative and negative nodes were classified into 4 groups according to the PgR and the Ki-67 status and were retrospectively examined. The analysis was based on the clinicopathological findings, and includes the recurrence score (RS) and disease-free survival (DFS) rates. Patients with invasive breast cancer (n=1866) were classified as LA (high PgR/low Ki-67), LB-1 (high PgR/high Ki-67), LB-2 (low PgR/high Ki-67), and LB-3 (low PgR/low Ki-67). In addition, 41 of the cases underwent a 21-gene expression assay. The data revealed that T1 tumors were more prevalent in the LA group and rare in the LB-2 group. Furthermore, nuclear grade 3 and p53 overexpression was revealed to be significantly correlated with LB-2. In terms of prognosis, LA had a significantly more favorable DFS; however, no differences were observed in the LB-3 group. LB-2 had a significantly worse DFS in all cases, and in the cases administered with endocrine therapy alone. Chemotherapy in combination with endocrine therapy was administered to cases with a higher risk of recurrence. In the LB-2 group, there was no difference in the DFS rates between the cases with endocrine therapy and chemo-endocrine therapy. These findings suggest that chemotherapy could improve the DFS in the LB-2 group. In addition, the majority of cases with LA, LB-3 and LB-1 had a RS of ≤25 and the majority of the LB-2 cases had a RS of >25. The patients with LA and LB-3 had a favorable DFS even in the group that received endocrine therapy alone. LB-2 was significantly correlated with a higher degree of malignancy and benefited from chemotherapy. These data suggest that the PgR and the Ki-67 status are effective in predicting prognosis, and for deciding on the most effective treatment strategy in patients with breast cancer.

Abstract Background: Breast cancer is no longer a single disease with high molecular heterogeneity. Gene profiling has identified at least 4 subtypes: Luminal A, Luminal B, HER2-enriched and basal-like breast cancer. Moreover, immunohistochemistry (IHC) classification is now considered a surrogate for establishing breast cancer subtypes. In previous report Luminal A was defined as ER and PgR positive, HER2 negative, Ki-67 low and recurrence risk low based on the multi-gene-expression assay. The distinction between Luminal A-like and Luminal B-like can be made by either using a high Ki-67 value (≥20%) or a low PgR value (< 20%). In this study, patients with ER positive, HER2 negative and negative node were classified into 4 groups according to the PgR and the Ki-67 status (cutoff points: 20%) and examined retrospectively in relation to clinicopathological findings including the recurrence score (RS) and disease-free survival (DFS). Methods: A total of 1866 invasive breast cancer patients from November 2001 to November 2016 were included in this study. The cases were classified as follows; LA as high PgR/low Ki-67 (850 cases), LB1 as high PgR/high Ki-67 (553 cases), LB2 as low PgR/high Ki-67 (226 cases), and LB3 as low PgR/low Ki-67 (237 cases). Out of all these cases, 1510 were treated with endocrine therapy alone. The median follow-up period was 78.1 months. Moreover, 23 of the cases underwent a 21-gene expression assay and the RS (< 25 and > 26) was compared with our classification. Results: The median age was 57.4 years (range: 25 - 94). T1 tumors were more common in the LA group and rare in the LB2 group. Nuclear grade 3 and p53 overexpression were significantly correlated with LB2. Endocrine therapy alone was performed in 87.4% (LA), 77.4% (LB1), 58.8% (LB2) and 86.9% (LB3), retrospectively. There were significant differences in DFS between the LA group (5y DFS: 98%, 10 y DFS: 95.9%) and the LB2 group (5y: 89.9%, 10y: 83.6%; p<0.0001) or LB1 (5y: 94.9%, 10y: 89.5%; p<0.0001), but there was no difference with the LB3 group (5y: 98.6%, 10y: 94.7%; p=0.88). In the cases with endocrine therapy alone, LA showed a similar DFS with LB3 (p=0.25). LB2 had a significantly worse DFS in all the cases and in the cases with endocrine therapy. Chemotherapy was administered to cases with a higher nuclear grade in combination with endocrine therapy. In the LB2 group, there was no difference in DFS between the cases with endocrine therapy and in the cases with chemo-endocrine therapy. Moreover, most of the cases with LA (1/1) and LB1 (15/16) had a RS of <25, and all of the LB2 (6/6) cases had a RS of >26. Conclusion: The patients with LA and LB3 (both: Ki-67<20%) had a favorable DFS even in the endocrine therapy alone group. However, LB1 and LB2 (both: Ki-67≥20%) had a poorer DFS. Moreover, LB2 (PgR<20% and Ki-67≥20%) was significantly correlated with a higher degree of malignancy and benefited from chemotherapy. LA and LB3 with low Ki-67 values were considered to be a part of the Luminal A group. These data suggest that PgR and the Ki-67 status are useful in predicting prognosis and deciding the treatment strategy for patients with ER-positive and HER2 negative breast cancer. Citation Format: Arima N, Nishimura R, Osako T, Nishiyama Y, Okumura Y, Fujisue M, Toyozumi Y. Ki-67 index value and progesterone receptor status predict prognosis and suitable treatment in node-negative breast cancer patients with estrogen receptor positive and HER2 negative tumors [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-32.

A 53-year-old woman was referred to our hospital with a 40-mm splenic tumor, which was detected incidentally on abdominal computed tomography during hospitalization for pyelonephritis. The tumor was hypointense on T2-weighted imaging and gradually enhanced on dynamic study. The tumor increased in size over a six-month period. Since we could not exclude splenic malignancy, we performed laparoscopic partial splenectomy. Histological examination revealed multiple angiomatoid nodules with three distinct vessel types. Pathologically, the tumor was diagnosed as a sclerosing angiomatoid nodular transformation (SANT). We then examined the correlation between the imaging and pathological findings, and performed a review of previous reports, concluding that contrast-enhanced MRI was the most useful modality for diagnosing SANT.

e12020 Background: Expression of the estrogen (ER) and progesterone receptor (PgR) is still clinically important in predicting prognosis and determining therapeutic strategies in breast cancer. According to the ASCO and CAP guidelines tumors with ≥1% positively staining cells should be considered ER/PgR positive. The clinical significance of low-ER/PgR-staining (1-9%) tumors were analyzed to investigate the biology and prognosis. Methods: This study examined 3193 consecutive HER2 negative invasive breast cancer cases. Clinicopathological characteristics and prognosis of hormone receptor (HR)-negative (<1%), low-HR-staining (1-9%) tumors and positive (≥ 10%) tumors were compared. The median follow-up period was 75 months. Results: The following is the number of patients in each of the tumor categories: 466 ER cases (14.6%) and 775 PgR cases (24.2%) in the <1% group; 68 ER cases (2.1%) and 218 PgR cases (6.8%) in the 1-9% group; and 2559 ER cases and 2200 PgR cases in the ≥ 10% group. The age groups were; young (≤35 y), premenopausal (36-50 y), postmenopausal (51-65 y) and the elderly (≥66 y). The median ER positive cell rate was significantly lower in the young group. In contrast, the PgR expression was significantly higher in the premenopausal group and significantly lower in the postmenopausal group. Patients in the ≥10% group had significantly smaller tumors, lower Ki-67 values, a lower p53 overexpression and nuclear grade. The elderly group had better disease-free survival (DFS) and the young group had the lowest DFS. In addition, DFS by ER/PgR expression was more favorable in the ≥ 10% group than the other groups. Patients with 1-9% ER had significantly lower DFS than those in the ≥10% elderly group. Patients with 1-9% PgR had significantly lower DFS than those in all the ≥10% groups and significantly lower DFS than those in the <1% premenopausal group. Multivariate analysis for DFS revealed that PgR expression, lymph node metastasis and tumor size were significant prognostic factors. Conclusions: There was a clear difference in the PgR expression rate due to the menopausal status. Moreover, the 1-9% ER and PgR groups had biological features that were similar to ER/PgR-negative tumors.

Introduction The recent diagnostic modality such as MRI can diagnose a tiny breast lesion even in healthy contralateral breasts. Recently, the rate of contralateral prophylactic mastectomy (CPM) is on the rise in the United States. In Japan, the CPM has been started for selected patients with a high risk. In this study, we divided bilateral breast cancers into the synchronous and the metachronous group and then compared the clinical features and biology. Patients and Methods Out of 216 bilateral breast cancer patients who underwent surgery between 1995 and March 2015, there were 101 synchronous breast cancer cases and 115 metachronous breast cancer cases (interval to the second tumor u003e 1 year). The items examined were age, tumor size, lymph nodal status, histological type, and biological markers (ER, PgR, HER2, p53 and Ki-67 index values) in the cases with paired data. Results 1. The incidence of metachronous tumors was relatively stable at 2.1–2.7% throughout the period. On the other hand, the incidence of synchronous tumors has increased to 4.4% in the most recent 5-year period and the median interval was 7.1 years. 2. There was no difference in the tumor size of both tumors in the synchronous group, but the second tumor was significantly smaller than the first tumor in the metachronous group (2.2cm to 1.7cm). The node negative rates showed no difference between two groups. 3. The cases with DCIS were seen in 20% and 25% of the synchronous group and 12% and 16% of the metachronous group. Most of the patients (94.3%) with invasive cancer received systemic adjuvant therapy in the metachronous group. 4. The ER positive rates of both tumors were 87.1% and 88.1% in the synchronous group and 71.6% and 68.4% in the metachronous group, respectively. The concordance rates were higher in the synchronous group (p=0.02). Moreover, there was a significant difference in ER positive rates between the two groups (p=0.01) and the ER negative tumors were more frequent in the second tumor of the metachronous group. The PgR negative tumors increased in the second tumor of metachronous cases. The shorter the interval ( 5. The Ki-67 index values significantly increased in the second tumor of the metachronous group, especially in the cases with a shorter interval. However, there was no difference in the synchronous group. The p53 overexpression rates significantly increased in the cases with a shorter interval. 6. The postoperative prognosis for the first tumor did not differ in both groups. Conclusion The incidence of synchronous bilateral breast cancer cases have increased but have remained relatively stable in the metachronous group. The concordance rates of the ER, PgR, Ki-67 and p53 status were higher in the synchronous group but the cases with negative ER, negative PgR, higher Ki-67 values and positive p53 increased in the second tumor of the metachronous group. These findings suggest that adjuvant systemic therapy played a important role in the treatment of bilateral breast cancer but the secondary tumor was more aggressive in the metachronous cases. Citation Format: Arima N, Nishimura R, Osako T, Nishiyama Y, Fujisue M, Okumura Y, Murakami K, Toyozumi Y. The difference between metachronous and synchronous bilateral breast cancer in terms of clinical features and biology. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-26.

Follicular lymphoma (FL) occasionally transforms into diffuse large B-cell lymphoma (DLBCL). This is generally associated with a poor prognosis, necessitating more potent chemotherapy as salvage treatment. However, de novo DLBCL, but not DLBCL transformed from FL, can be treated as primary DLBCL. We encountered a 63-year-old woman who developed DLBCL after a 9-year remission following treatment of FL. To differentiate DLBCL transformed from FL and de novo DLBCL, VDJ gene rearrangements in IgH were examined by PCR using biopsy specimens from both lymphomas. The results revealed the two lymphomas to be different clones. Thus, she was diagnosed with primary DLBCL. Therefore, routine chemotherapy and radiation therapy were conducted for the primary DLBCL with a limited stage, achieving complete remission. Treatment based on the clonality assessment of VDJ gene rearrangements is potentially useful for treating late relapse of B-cell lymphoma according to the pathological conditions of patients.

AIM:Insufficient attention for the Ki-67 immunohistochemistry has been given to the importance of tissue handling for surgical breast cancer specimens. We sought to investigate the effect of fixation status on the Ki-67.METHODS:We examined the effect of fixative, time to and duration of fixation using surgical specimens, and finally, compared the paired Ki-67 index in the tumour between core needle and surgical specimen.RESULTS:The Ki-67 was significantly higher when 10% neutral buffered formalin was used (p=0.0276). Insufficient fixation caused a drastic reduction in the Ki-67 index (p=0.0177), but not significant in oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). Sixteen hours delayed time to fixation also caused a reduction of the Ki-67 (p=0.0284), but not significant in ER. Prolonged fixation significantly led to a gradual reduction in the Ki-67 in a time-dependent manner, but not in both ER and HER2. Finally, cutting the tumour before fixation improved fixation status and consequently caused an increased level of the Ki-67 index (p=0.0181), which resulted in a strong correlation of the Ki-67 between core needle and surgical specimen (r=0.8595).CONCLUSIONS:Tissue handling of surgical specimen is critical for assessing the Ki-67 compared with ER and HER2. We should pay more attention to tissue fixation status for the standard assessment of the Ki-67 index.

Objective: In this case-control study, we investigated the most suitable cell counting area and the optimal cutoff point of the Ki-67 index. Methods: Thirty recurrent cases were selected among hormone receptor (HR)-positive/HER2-negative breast cancer patients. As controls, 90 nonrecurrent cases were randomly selected by allotting 3 controls to each recurrent case based on the following criteria: age, nodal status, tumor size, and adjuvant endocrine therapy alone. Both the hot spot and the average area of the tumor were evaluated on a Ki-67 immunostaining slide. Results: The median Ki-67 index value at the hot spot and average area were 25.0 and 14.5%, respectively. Irrespective of the area counted, the Ki-67 index value was significantly higher in all of the recurrent cases (p < 0.0001). The multivariate analysis revealed that the Ki-67 index value of 20% at the hot spot was the most suitable cutoff point for predicting recurrence. Moreover, higher ΔKi-67 index value (the difference between the hot spot and the average area, ≥10%) and lower progesterone receptor expression (<20%) were significantly correlated with recurrence. Conclusion: A higher Ki-67 index value at the hot spot strongly correlated with recurrence, and the optimal cutoff point was found to be 20%.

背景 : 乳腺分泌癌は浸潤癌の特殊型に分類されるまれな腫瘍である. 若年者に多くみられることから以前は若年性癌と呼ばれていたが, 近年では成人の報告例が多い. 分泌所見が乏しい症例では細胞異型が軽度なため, 良性病変と誤診されることがある. 当院で分泌癌と診断された 3 例の細胞所見を再検討し, その正診率向上のために必要な所見の抽出を試みた.

A.B. Benson, Chicago, Ill. A. Chang, Singapore A.L. Cheng, Taipei J.F. Cleary, Madison, Wis. M. Dietel, Berlin M.S. Ernstoff, Cleveland, Ohio M.G. Fakih, Duarte, Calif. J.J. Grau, Barcelona H. Gronemeyer, Illkirch D.F. Hayes, Ann Arbor, Mich. C.S. Johnson, Buffalo, N.Y. M.J. Kelley, Durham, N.C. L. Kumar, New Delhi P.J. Loehrer, Indianapolis, Ind. J.R. Marshall, Buffalo, N.Y. S. Monfardini, Milan R. Nagler, Haifa R. Ohno, Nagoya B. Pestalozzi, Zurich H.M. Pinedo, Amsterdam E.A. Repasky, Buffalo, N.Y. A. Semczuk, Lublin E.F. Smit, Amsterdam C.N. Sternberg, Rome R. Stupp, Zurich M.S. Tallman, New York, N.Y. S. Tanaka, Hiroshima M. Tian, Houston, Tex. D.L. Trump, Buffalo, N.Y. T. Wiegel, Ulm W. Yasui, Hiroshima H. Zhang, Hangzhou City Editor-in-Chief

Abstract Introduction The recent diagnostic modality such as MRI can diagnose a tiny breast lesion even in healthy contralateral breasts. Recently, the rate of contralateral prophylactic mastectomy (CPM) is on the rise in the United States. In Japan, the CPM has been started for selected patients with a high risk. In this study, we divided bilateral breast cancers into the synchronous and the metachronous group and then compared the clinical features and biology. Patients and Methods Out of 216 bilateral breast cancer patients who underwent surgery between 1995 and March 2015, there were 101 synchronous breast cancer cases and 115 metachronous breast cancer cases (interval to the second tumor > 1 year). The items examined were age, tumor size, lymph nodal status, histological type, and biological markers (ER, PgR, HER2, p53 and Ki-67 index values) in the cases with paired data. Results 1. The incidence of metachronous tumors was relatively stable at 2.1–2.7% throughout the period. On the other hand, the incidence of synchronous tumors has increased to 4.4% in the most recent 5-year period and the median interval was 7.1 years. 2. There was no difference in the tumor size of both tumors in the synchronous group, but the second tumor was significantly smaller than the first tumor in the metachronous group (2.2cm to 1.7cm). The node negative rates showed no difference between two groups. 3. The cases with DCIS were seen in 20% and 25% of the synchronous group and 12% and 16% of the metachronous group. Most of the patients (94.3%) with invasive cancer received systemic adjuvant therapy in the metachronous group. 4. The ER positive rates of both tumors were 87.1% and 88.1% in the synchronous group and 71.6% and 68.4% in the metachronous group, respectively. The concordance rates were higher in the synchronous group (p=0.02). Moreover, there was a significant difference in ER positive rates between the two groups (p=0.01) and the ER negative tumors were more frequent in the second tumor of the metachronous group. The PgR negative tumors increased in the second tumor of metachronous cases. The shorter the interval (< 5years), the more the ER positive rate decreased (p=0.002). However, the longer interval did not correlate with the change of receptor status. 5. The Ki-67 index values significantly increased in the second tumor of the metachronous group, especially in the cases with a shorter interval. However, there was no difference in the synchronous group. The p53 overexpression rates significantly increased in the cases with a shorter interval. 6. The postoperative prognosis for the first tumor did not differ in both groups. Conclusion The incidence of synchronous bilateral breast cancer cases have increased but have remained relatively stable in the metachronous group. The concordance rates of the ER, PgR, Ki-67 and p53 status were higher in the synchronous group but the cases with negative ER, negative PgR, higher Ki-67 values and positive p53 increased in the second tumor of the metachronous group. These findings suggest that adjuvant systemic therapy played a important role in the treatment of bilateral breast cancer but the secondary tumor was more aggressive in the metachronous cases. Citation Format: Arima N, Nishimura R, Osako T, Nishiyama Y, Fujisue M, Okumura Y, Murakami K, Toyozumi Y. The difference between metachronous and synchronous bilateral breast cancer in terms of clinical features and biology. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-26.

Abstract Background: Uncontrolled proliferation is a key factor of malignant tumors. The Ki-67 index is known to be a significant prognostic factor in terms of disease-free and overall survival in breast cancer. However, there are several limitations in the use of this biomarker, the biggest being a difference in opinion among breast cancer specialist on how to create an international standard for the Ki-67 index. Therefore, the aim of this case control study was to investigate the most suitable area to count and to determine the optimal cut-off point of the Ki-67 index for a more accurate prognosis. Patients and Methods: Thirty recurrent cases (< 5 years after initial treatment) were selected among hormone receptor (HR)-positive/HER2-negative breast cancer patients. As a control, 90 non-recurrent cases (>5 years after initial treatment) were randomly selected by allotting 3 controls to each recurrent case based on the following predetermined criteria; age, nodal status and tumor size. All patients were treated with adjuvant endocrine therapy alone. Both the hot spot and the average area of the tumor were evaluated on a Ki-67 immunostaining slide and then photographs were taken. The Ki-67 index was automatically scored using the CountσCell (Seiko Tech., Fukuoka, Japan). Moreover, the difference in the Ki-67 index values (ΔKi-67) between the hot spot and the average area were calculated. The Chi-square and Fisher’s exact tests were used for inter-group comparison. Paired t-test and Wilcoxon’s (non-parametric) test were used to compare the mean value for the Ki-67 index values. Logistic regression analysis was used to calculate the odds ratio of the Ki-67 index related to recurrence. Results: 1) A higher Ki-67 index value at the hot spot was more significantly associated with recurrence than the average area, and the Ki-67 index value of 20% at the hot spot was the most suitable cut-off point for predicting recurrence. Irrespective of the area counted, the Ki-67 index value was significantly higher in all of the recurrent cases (p<0.0001). The next step was to determine the most suitable cut-off point for the Ki-67 index. Out of all the cut-off points used in this study, the most significant difference was found in the values 20, 25 and 30% at only the hot spot (each p<0.0001). Furthermore, logistic regression analysis demonstrated that the highest odds ratio was 20% at the hot spot. 2. The ΔKi-67 index value was significantly correlated with recurrence and the ΔKi-67 index value of 10% was the most suitable cut-off point. The ΔKi-67 index values ranged from 2 to 54% (median: 10%) and significantly correlated with recurrence and the Ki-67 value at hot spot (p<0.0001). Logistic regression analysis revealed that a ΔKi-67 index cut-off point of 10%. Conclusion: A higher Ki-67 index value at the hot spot was strongly correlated with recurrence, and the most suitable cut-off point was 20%. ΔKi-67 index value also significantly correlated with recurrence, and the most suitable cut-off point was 10%. Finally, the hot spot counting method is strongly related to tumor biology and prognosis in HR-positive/HER2-negative breast cancer. Citation Format: Nobuyuki Arima, Reiki Nishimura, Tomofumi Osako, Yasuyuki Nishiyama, Yasuhiro Okumura, Masahiro Nakano, Mamiko Fujisue, Rumiko Tashima, Yasuo Toyozumi. A comparison of the hot spot and the average cancer cell counting methods and the optimal cut-off point of the Ki-67 index for luminal type breast cancer with or without recurrence – A case control study for prognostic factors [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-02-03.

背景 : Mammary analogue secretory carcinoma of the salivary gland (MASC) は Skalova らにより最初に紹介された乳腺分泌癌と同一の遺伝子転座を示す唾液腺腫瘍である. 今回, 私どもは副耳下腺に発生した MASC の 1 例を経験し, 腺房細胞癌との細胞学的鑑別点について検討したので報告する. 症例 : 患者は 24 歳男性. 右頬部の腫脹と疼痛にて来院し, 腫瘍切除術を施行. 当初は副耳下腺原発の腺房細胞癌と診断していたが, 乳腺分泌癌との形態学的類似性から, RT-PCR 法にて ETV6-NTRK3 キメラ融合遺伝子を証明し, MASC と最終診断した. 細胞所見を再検討するに, ヘモジデリン貪食組織球が目立つ背景, シート状・濾胞状・乳頭状の細胞集塊, 軽度の細胞異型, 乏しい zymogen 顆粒は MASC も考慮すべき所見であったが, 背景に粘液が乏しく, 腺房細胞癌との細胞学的鑑別は必ずしも容易でなかった. 結論 : MASC の診断には乳腺分泌癌に類似した形態所見の拾い上げや S-100 蛋白や mammaglobin の免疫染色が有用であるが, 確定診断には融合遺伝子の証明が避けられないと思われた.