A rare case of a huge malignant pleural mesothelioma presenting in the posterior mediastinum.

We report a case of a 69-year-old woman with pleural mesothelioma presenting in the posterior mediastinum with a maximum diameter of 25 cm. She had a chronic cough and a pleural effusion was noted on chest X-ray. The examination of the effusion showed high hyaluronic acid levels, and mesothelioma was suspected. A chest computed tomography scan showed a huge mediastinal mass, which caused rapid progression of respiratory failure and compression of the heart. Sufficient tissue samples could not be obtained before death. The patient died approximately 1 month after the initial visit, and a pathological autopsy was performed. The diagnosis of malignant pleural mesothelioma was made. Malignant pleural mesothelioma with a huge posterior mediastinal mass such as in this case is considerably rare; however, it is a rapidly progressing form of the disease and is reported here as an important differential diagnosis for mediastinal tumours.

Expression of vascular endothelial growth factor receptor in thymic epithelial tumors.

Thymic epithelial tumors (TETs) are rare and the major symptoms are not obvious until the tumor progresses to a relatively large size and compresses the surrounding organs. As its growth is aggressive and it metastasizes to distant organs, it is important to find novel effective therapies. Lenvatinib, a vascular endothelial growth factor receptor (VEGFR) inhibitor, is approved as a drug therapy for thymic carcinoma (TC); however, although it is a molecular targeted therapy, there are no obvious predictors of therapeutic efficacy. The present study aimed to assess the association between clinicopathological factors and the protein expression of VEGFR, which is associated with tumor aggressiveness and the efficacy of VEGFR inhibitors. The VEGFR-2 protein expression was evaluated in 144 patients with TETs who underwent surgical resection. The present study assessed whether the expression of VEGFR-2 protein was associated with TET classification and pathological stage, progression-free survival and overall survival (OS). A total of 94 cases (65.2%) were positive for VEGFR-2 protein. The expression of VEGFR-2 was higher in the more aggressive type B3 thymoma and TC (88.5%) than in types A, AB, B1 and B2 thymoma (60.2%). The 5-year OS rate for the overall population was 53.1%. The 5-year OS rates of patients with negative VEGFR-2 staining score values (66.5%) were significantly longer than in patients with positive VEGFR-2 staining score values (42.5%; P=0.000078). Furthermore, the pathological stage was the only factor significantly associated with OS in multivariate analysis. The results of the present study suggest the possibility that the indications for VEGF inhibitor therapy could be extended to type B3 thymoma.

Comprehensive genomic profiling of salivary gland carcinoma: Analysis of the Center for Cancer Genomics and Advanced Therapeutics database in Japan.

Comprehensive information on genetic alterations in salivary gland cancer (SGC) is limited. This study aimed to elucidate the genetic and clinical characteristics of patients with SGC using the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, a Japanese national genomic database. We analyzed data of 776 patients with SGC registered in the C-CAT database between June 1, 2019, and June 30, 2023. Adenoid cystic carcinoma was the most common histologic type, followed by salivary duct carcinoma (SDC) and adenocarcinoma not otherwise specified. Genetic data of 681 patients receiving FoundationOne® CDx were analyzed. We identified specific features of the combination of TP53 and CDKN2A alterations among the histological types. Specific LYN amplification was mainly detected in carcinoma ex pleomorphic adenoma and myoepithelial carcinoma. For SDC, the frequency of ERBB2 and BRAF alterations were higher in cases with metastatic lesions than in those with primary lesions. Although 28.6% patients were offered recommended treatment options, only 6.8% received the recommended treatments. This study highlights the differences in genetic alterations among the histological types of SGC, with comprehensive genomic profiling tests revealing lower drug accessibility. These findings could contribute to the development of personalized treatment for patients with SGC.

Fluorescent periodic acid Schiff-like staining combined with standard cytologic staining of the same cytologic specimen may facilitate cytopathologic diagnosis.

BACKGROUND: Periodic acid Schiff (PAS) staining which detects glycogen and mucosubstances is frequently used as an ancillary method for an accurate cytopathologic diagnosis. Unfortunately, cytologic slides for PAS stain are not routinely prepared. Aqueous 7-amino-4-methylcoumarin (AMC) is colorless and transparent under bright field illumination but exhibits strong fluorescence under ultraviolet (UV) light and can be used as a Schiff reagent. We recently reported that combining [author: Please define (H&E) in the first occurrence if necessary.]H&E and AMC is useful for histopathologic diagnosis of various disease conditions. In this study, we investigated whether standard cytologic staining (Papanicolaou [Pap] and Giemsa) combined with AMC was useful for cytopathologic analysis. METHODS: Specimens of non-neoplastic human tissues and archived cytologic specimens of various disease conditions were stained with a combination of Pap and AMC (Pap/AMC) or Giemsa and AMC (Giemsa/AMC). RESULTS: The addition of AMC had no significant effect on Pap or Giemsa staining, and the cytomorphology under bright field microscopy was perfectly preserved. The AMC fluorescent signals observed under UV light were intense and the staining pattern was identical to that obtained by PAS staining. Diastase digestion differentiated glycogen from other AMC-positive elements. The efficacy of using Pap/AMC and Giemsa/AMC for archived cytologic specimens was demonstrated in several diseases including cases of endometrial carcinoma, adenoid cystic carcinoma, metastatic signet-ring cell carcinoma, candidiasis, and trichomoniasis. CONCLUSION: Pap/AMC and Giemsa/AMC are useful in aiding cytopathologic diagnosis especially when the information gained from PAS staining is critical and cytologic specimens for PAS are not available.

Low Daily Step Count Associated with Small Erector Spine Muscle Area and Sarcopenia in Idiopathic Pulmonary Fibrosis.

Objective The daily step count is associated with mortality in idiopathic pulmonary fibrosis (IPF). However, the factors associated with this phenomenon are not yet fully understood. We therefore clarified its association with clinical parameters. Methods Fifty-nine patients with IPF with available data for daily step counts; 6-minute walk distance (6MWD); chest, abdominal, and pelvic computed tomography (CT); pulmonary function; psychological evaluations; and sarcopenia assessments were prospectively enrolled. The daily step count was measured continuously for seven consecutive days. The cross-sectional areas of the erector spinae muscles at the level of the 12th vertebra (ESMCSA) and psoas major muscle volume (PMV) obtained by CT were assessed. Results The average age of the patients was 73.3±8.1 years old, and the percent predicted forced vital capacity was 81.6% ±15.8%. The average daily step count was 4,258 (2,155-6,991) steps. The average 6MWD, ESMCSA, and PMV were 413±97 m, 25.5±6.7 cm2, and 270±75.6 cm3, respectively. A linear regression analysis for daily step count showed that the ESMCSA and 6MWD were independent factors for the daily step count, whereas the PMV and skeletal muscle index were not. The daily step count, ESMCSA, and 6MWD were lower in patients with sarcopenia than in those without sarcopenia. Conclusions A lower daily step count was associated with a smaller erector spinae muscle area and sarcopenia in patients with IPF. Further studies are warranted to confirm the importance of physical therapy for muscle strengthening in patients with IPF.

Importance of the Number and Location of Lymph Node Metastasis in Oropharyngeal Cancer.

BACKGROUND/AIM: The 8th edition of the American Joint Committee on Cancer staging system classifies oropharyngeal cancer (OPC) by the expression of p16. The discrepancy observed in this system between pathological and clinical N-stages in p16-positive OPC has provoked controversy. Therefore, this study investigated prognostic factors not included in the new staging system for p16-positive OPC patients. PATIENTS AND METHODS: Patients with non-metastatic OPC receiving radiotherapy were reviewed. Clinical lymph node statuses were reassessed based on contrast-enhanced computed tomography and fluorodeoxyglucose positron emission tomography. Overall survival (OS) and cause-specific survival (CSS) were analyzed using multivariate analyses to adjust baseline imbalances. RESULTS: In total, 166 OPC patients were reviewed. Among them, 81 patients with p16-positive were analyzed. Three or more lymph node metastases (LNM) were observed in 21 p16-positive OPCs. Retropharyngeal lymph node metastasis (Rp) was found in 12. Three-year OS, CSS, and progression-free survival rates in p16-positive patients were 76, 88, and 81%, respectively. In multivariate analyses of p16-positive OPC, LNM ≥3 was a prognostic factor of OS (hazard ratio=9.30, p<0.001) and CSS (hazard ratio=17.80, p=0.005). Rp was associated with poor CSS (hazard ratio=8.73, p=0.03). In N0-1 p16-positive patients, LNM ≥3 trended to be associated with poor OS (hazard ratio=3.93, p=0.06). CSS in patients with Rp was unfavorable (hazard ratio=70.16, p=0.05). CONCLUSION: LNM ≥3 and Rp may be predictive of OS and CCS in p16-positive OPC. These are also possibly used to subcategorize p16-positive cN0-1 OPC. Further validation of lymph node staging is needed to refine the clinical staging system.

Prognostic scores for patients with salivary adenoid cystic carcinoma without lymph node metastasis.

Adenoid cystic carcinoma (AdCC) of salivary gland grows relatively slowly, but occasionally develops distant metastasis. Although cervical lymph node metastasis (LNM) has been reported as a strong prognostic factor, most of AdCC do not have LNM. In this study, we investigated the prognostic factors to predict disease free survival (DFS), distant metastasis free survival (DMFS), and overall survival (OS) for 175 patients surgically treated for AdCC without LNM, and developed prognostic score (PS) determined as number of positive prognostic factors. The following emerged as significant prognostic factors: positive surgical margin in DFS, pT3/4 and positive surgical margin in DMFS, and positive surgical margin and high-histological grade in OS. 10-year DFS rates were 56.4% in PS0, and 19.1% in PS1 (p < 0.0001). 10-year DMFS rates were 86.3% in PS0, 56.4% in PS1, and 30.7% in PS2 (p < 0.0001). 10-year OS rates were 100% in PS0, 73.3% in PS1, and 38.8% in PS2 (p < 0.0001).

The Landscape of MYB/MYBL1- and Peri-MYB/MYBL1-Associated Rearrangements in Adenoid Cystic Carcinoma.

Approximately 60% of adenoid cystic carcinoma (AdCC) cases are positive for MYB::NFIB or MYBL1::NFIB, whereas MYB/MYBL1 oncoprotein, a key driver of AdCC, is overexpressed in most cases. Juxtaposition of superenhancer regions in NFIB and other genes into the MYB/MYBL1 locus is an attractive oncogenic hypothesis for AdCC cases, either negative or positive for MYB/MYBL1::NFIB. However, evidence supporting this hypothesis is insufficient. We examined 160 salivary AdCC cases for rearrangements in MYB/MYBL1 loci and peri-MYB/MYBL1 areas (centromeric and telomeric areas of 10 Mb each) using formalin-fixed, paraffin-embedded tumor sections. For the detection of the rearrangements, we employed conventional fluorescence in situ hybridization split and fusion assays and a 5 Mb fluorescence in situ hybridization split assay. The latter is a novel assay that enabled us to detect any possible splits within a 5 Mb distance of a chromosome. We found MYB/MYBL1- and peri-MYB/MYBL1-associated rearrangements in 149/160 patients (93%). AdCC cases positive for rearrangements in MYB, MYBL1, the peri-MYB area, and the peri-MYBL1 area numbered 105 (66%), 20 (13%), 19 (12%), and 5 (3%), respectively. In 24 peri-MYB/MYBL1 rearrangement-positive cases, 14 (58%) were found to have a juxtaposition of the NFIB or RAD51B locus into the MYB/MYBL1 loci. On comparing with a tumor group positive for MYB::NFIB, a hallmark of AdCC, other genetically classified tumor groups had similar features of overexpression of the MYB transcript and MYB oncoprotein as detected by semiquantitative RT-qPCR and immunohistochemistry, respectively. In addition, clinicopathological and prognostic features were similar among these groups. Our study suggests that peri-MYB/MYBL1 rearrangements may be a frequent event in AdCC and may result in biological and clinicopathological consequences comparable to MYB/MYBL1 rearrangements. The landscape of MYB/MYBL1 and peri-MYB/MYBL1 rearrangements shown here strongly suggests that juxtaposition of superenhancers into MYB/MYBL1 or peri-MYB/MYBL1 loci is an alteration that acts as a key driver for AdCC oncogenesis and may unify MYB/MYBL1 rearrangement-positive and negative cases.

7-Amino-4-methylcoumarin as a fluorescent substitute for Schiff's reagent: a new method that can be combined with hemalum and eosin staining on the same tissue section.

An aqueous 7-amino-4-methylcoumarin (AMC) solution exhibits strong fluorescence under ultraviolet (UV) light and can be used as a Schiff reagent to visualize aldehydes. We investigated hemalum and eosin (H & E) and AMC staining for histological and pathological analysis. Sections of normal and lesioned human tissues were stained with combined H & E/AMC staining. After H & E/AMC staining, the H & E morphology was preserved under bright field microscopy. The AMC fluorescent signals observed under UV light were intense and the staining pattern was identical to that obtained by periodic acid-Schiff (PAS) staining. AMC staining of archived H & E sections also was successful. Diastase digestion differentiated glycogen from other AMC positive elements. Using H & E/AMC staining, mucus-rich adenocarcinoma cells, amebic trophozoites and fungal hyphae were visualized clearly under UV excitation. Using H & E/AMC staining, H & E and PAS-like histological imaging can be obtained using a single tissue section. H & E/AMC is useful for pathologic diagnosis especially when information from PAS staining is critical, the number of tissue sections is limited and/or the lesion in question is small.

A Transanal Endoscopic Ultrasound-guided Fine-needle Aspiration Biopsy for an Intrapelvic Tumor Diagnosed as Recurrence of a Smooth Muscle Tumor of Uncertain Malignant Potential Following Uterine Morcellation.

A transoral endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) is a well-established tissue-sampling method. However, performing a transanal EUS-FNAB remains challenging. Uterine morcellation has emerged as a minimally invasive approach for benign tumor treatment. However, uterine myomas are heterogeneous and include malignant and indeterminate malignant cells. We herein report a rare case of intrapelvic tumor diagnosed by a transanal EUS-FNAB as a recurrence of smooth muscle tumors of uncertain malignant potential following uterine morcellation. Physicians should be aware that a previous uterine myoma resected under morcellation has the possibility of intra-abdominal recurrence. A transanal EUS-FNAB is a practical option for making a pathological diagnosis.

SARC-F scores can predict health status and daily activity in patients with idiopathic pulmonary fibrosis.

Background: The strength, assistance in walking, rising from a chair, climbing stairs, and falls questionnaire (SARC-F) is widely used for screening sarcopenia. We aimed to examine the association of SARC-F scores with the measurements of quality of life and activity in patients with idiopathic pulmonary fibrosis (IPF). Methods: This cross-sectional pilot study prospectively enrolled 54 patients with IPF who completed pulmonary function tests, the 6-min walk test, the chronic obstructive pulmonary disease assessment test (CAT), St. George's Respiratory Questionnaire (SGRQ), the Hospital Anxiety and Depression Scale, and a daily step count. The daily step count was measured continuously for 7 consecutive days using a tri-axis accelerometer device. Results: The mean age was 73.6±7.9 years and the mean percent predicted forced vital capacity was 80.4%±15.6%. The median [interquartile range] SARC-F score, SGRQ total scores, and CAT scores were 2 [1-3.25], 28.8 [14.4-46.9], and 13 [7-22], respectively. SARC-F scores were correlated with the percent predicted forced vital capacity (r=-0.51, P<0.001), CAT score (r=0.57, P<0.001), SGRQ total score (r=0.77, P<0.001), Hospital Anxiety and Depression Scale anxiety score (r=0.31, P=0.025), and Hospital Anxiety and Depression Scale depression score (r=0.28, P=0.041). Linear regression analyses revealed that the 6-minute walk test (6MWT) (standardized ß=0.33, P=0.011) and SARC-F score (standardized ß=-0.39, P=0.005), but not the CAT score and SGRQ total score, were significant predictors for daily step count. Conclusions: SARC-F scores were correlated with health status and daily activity in patients with IPF. Further studies are warranted to validate the utility of the SARC-F in patients with IPF.

Frequency and impact on clinical outcomes of sarcopenia in patients with idiopathic pulmonary fibrosis.

OBJECTIVES: Sarcopenia is a syndrome characterized by reduced muscle mass and function. It is well-recognized as a complication in chronic diseases such as chronic obstructive pulmonary disease. However, little is known about sarcopenia in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to investigate the clinical characteristics of sarcopenia and the association between quality of life and sarcopenia in patients with IPF. METHODS: In this pilot cross-sectional study, 56 Japanese outpatients with IPF (49 men) were enrolled prospectively. Sarcopenia was diagnosed according to the criteria of the Asian Working Group for Sarcopenia 2019. Its associations with clinical parameters including age, pulmonary functions, physical performance, and patient-reported outcomes (PROs) were examined. RESULTS: The frequency of sarcopenia was 39.3% (n = 22) in this cohort. There were significant differences in St George's Respiratory Questionnaire (p = .005), modified Medical Research Council score (p = .004), and Hospital and Anxiety Depression Scale depression score (p = .030) between the sarcopenic and non-sarcopenic groups. On multivariate regression analysis, 6-min walk distance (6MWD) was an independent factor associated with sarcopenia (odds ratio 1.241, 95% confidence interval 1.016-1.515, p = .034). CONCLUSION: Sarcopenia was associated with PROs and physical performance in patients with IPF.

CCR7 alterations associated with inferior outcome of adult T-cell leukemia/lymphoma under mogamulizumab treatment.

Adult T-cell leukemia/lymphoma (ATL) patients have a very poor prognosis. The humanized anti-CCR4 therapeutic monoclonal antibody, mogamulizumab, is a key agent for ATL treatment. Our previous integrated molecular analysis demonstrated that among all the driver genes in ATL, CCR7 gene alterations were significantly associated with clinical response to mogamulizumab. Accordingly, here we investigated the detailed clinical impact of CCR7 alterations in a larger cohort of ATL patients. These CCR7 alterations, most of which lead to C-terminus truncations, were observed in 27 of 223 patients (12%). For patients receiving mogamulizumab but not allogeneic hematopoietic stem cell transplantation (HSCT), CCR7 alterations were significantly associated with worse survival (median survival from the first dose of mogamulizumab of 0.7 years for 12 patients with CCR7 alterations vs. 1.6 years for 72 patients without, p = 0.020). On the other hand, the presence or absence of CCR7 alterations had no significant impact on survival in the entire cohort (median overall survival of 1.4 and 1.8 years, respectively, p = 0.901), or on the survival of patients receiving allogeneic HSCT (median survival from the day of transplantation of 0.9 years for 6 patients with CCR7 alterations and 1.4 years for 48 without, p = 0.543). Multivariate analysis indicated that patients with CCR4 alterations but lacking CCR7 alterations (n = 20) had significantly better survival after receiving mogamulizumab-containing treatments (hazard ratio for survival, 0.437, 95% confidence interval, 0.192-0.994). This study contributes to the establishment of precision medicine for ATL.

Decreased peak expiratory flow rate associated with mortality in idiopathic pulmonary fibrosis: A preliminary report.

OBJECTIVES: The peak expiratory flow rate (PEFR) is known to decrease in patients with sarcopenia. However, little is known about the clinical impact of the PEFR in idiopathic pulmonary fibrosis (IPF). This study aimed to confirm whether a decrease in PEFR over 6 months was associated with survival in IPF patients. METHODS: Consecutive IPF patients who had been assessed at a single center were retrospectively analyzed. The relative decline in PEFR over 6 months was assessed. Survival analyses were performed by univariate and multivariate Cox proportional hazard models. RESULTS: A total of 61 eligible cases (average age 70 years) were examined, and 21 patients (34.4%) died. The univariate Cox regression analysis showed that the body mass index, baseline % predicted forced vital capacity (FVC), baseline % predicted PEFR, % predicted diffusion capacity for carbon monoxide (DLCO), relative decline in FVC, and relative decline in PEFR were prognostic factors. On multivariate analyses, relative decline in PEFR (hazard ratio [HR] 1.037, p < .05) and baseline % predicted FVC (HR 0.932, p < .001) were independent prognostic factors, whereas relative decline in FVC was not. CONCLUSION: A decrease in PEFR after 6 months may predict worse survival in patients with IPF.

Serum creatinine/cystatin C ratio is a surrogate marker for sarcopenia in patients with idiopathic pulmonary fibrosis.

BACKGROUND: The serum creatinine/cystatin C (Cr/CysC) ratio has attracted attention as a marker for sarcopenia, but has not been studied in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to confirm the utility of the serum Cr/CysC ratio in predicting sarcopenia and investigate its clinical relevance. METHODS: This cross-sectional pilot study prospectively enrolled patients with stable IPF. IPF was diagnosed through multidisciplinary discussions according to the 2018 international guidelines, and sarcopenia was diagnosed according to the 2019 consensus report of the Asian Working Group for Sarcopenia. Patient-reported outcomes (PROs) were evaluated using the modified Medical Research Council (mMRC) dyspnea scale, chronic obstructive pulmonary disease assessment test (CAT), and King's Brief Interstitial Lung Disease (K-BILD) questionnaire. The associations between serum Cr/CysC ratio and the presence of sarcopenia and other clinical parameters, including PROs scores, were examined. RESULTS: The study enrolled 49 Japanese patients with IPF with a mean age of 73.0 ± 7.7 years and a mean percentage of predicted forced vital capacity of 80.4 ± 15.5%. Sarcopenia was diagnosed in 18 patients (36.7%), and the serum Cr/CysC ratio was 0.86 [0.76-0.94] (median [interquartile range]). The receiver operating characteristic curve analyses for the detection of sarcopenia according to the serum Cr/CysC showed that the area under the curve, optimal cutoff value, specificity, and sensitivity were 0.85, 0.88, 0.65, and 0.94, respectively. Sarcopenia was identified in 13% of patients with a high serum Cr/CysC ratio (≥ 0.88) and 60% of patients with a low serum Cr/CysC ratio (< 0.88) (P < 0.001). Multiple linear regression analysis showed that the serum Cr/CysC ratio was an independent predictive marker of worse PROs evaluated using mMRC (P < 0.05), CAT (P < 0.05), and K-BILD (P < 0.05). CONCLUSIONS: This study showed that the serum Cr/CysC ratio may be a surrogate marker of sarcopenia in patients with IPF. Furthermore, it is important to pay attention to the serum Cr/CysC ratio because a lower serum Cr/CysC ratio is associated with worse PROs. Further studies are required to validate these observations to determine whether the Cr/CysC ratio can be used to detect sarcopenia in patients with IPF.

Thymic Mucoepidermoid Carcinoma: A Clinicopathologic and Molecular Study.

Thymic mucoepidermoid carcinoma (MEC) is a rare tumor, and its characteristics remain to be clarified. Here we investigated 20 cases of thymic MEC to systematically characterize its clinical, histopathologic, and molecular features. The median age of the patients was 56 years (range, 19 to 80 y), there was a slight male predilection (3:2), and 44% of the patients were asymptomatic at diagnosis. The median tumor size was 6.8 cm in diameter, 55% were pT1 tumors, and 50% were TNM stage I tumors. When 4 tumor grading systems for salivary MEC (Armed Forces Institutes of Pathology, Brandwein, modified Healey, and the Memorial Sloan-Kettering) were employed, low-grade, intermediate-grade, and high-grade tumors accounted for 35% to 70%, 5% to 25%, and 25% to 50%, respectively. Many histologic variants were noted, and 70% of the cases were classified as nonclassic variants. MAML2 rearrangement was detected in 56% of cases, and the fusion partner was CRTC1 in all cases. CRTC1-MAML2 fusion was associated with lower pT classification and lower TNM stage. The overall survival rate of all patients was 69% and 43% at 5 and 10 years, respectively. Worse overall survival was associated with higher pT stage, higher TNM stage, residual tumors, greater tumor size, high-grade tumor histology (Armed Forces Institutes of Pathology and Memorial Sloan-Kettering, but not the other 2), and with the absence of CRTC1-MAML2 fusion. Of note, none of the patients with CRTC1-MAML2 fusion-positive tumors died during the follow-up. In conclusion, the clinicopathologic and molecular findings of thymic MEC presented here are expected to contribute to the management of this rare tumor.

Salivary mucoepidermoid carcinoma: histological variants, grading systems, CRTC1/3-MAML2 fusions, and clinicopathological features.

AIMS: To investigate the histological diversity of salivary mucoepidermoid carcinoma (MEC), its clinicopathological features, and its associations with CRTC1/3-MAML2 fusions. METHODS AND RESULTS: Salivary MEC cases (n = 177) were examined for CRTC1/3-MAML2 fusions, histological variants were classified, and tumours were graded according to four different grading systems. Adverse histological features considered to be unusual in MEC were also investigated. Of the 177 MEC cases, 110 were positive for CRTC1/3-MAML2 fusions. The classical variant was the most frequent in the fusion-positive case group, the fusion-negative case group, and the total case group. The clear/oncocytic variant was the second most frequent in the fusion-positive and total case groups. Oncocytic, Warthin-like and spindle variants were seen in the fusion-positive case group only. Clear cell, sclerosing, mucinous and central variants were seen in both the fusion-positive case group and the fusion-negative case group. No case was classified as a ciliated variant, as a mucoacinar variant, or as a high-grade transformation. As compared with the classical variant, non-classical variants were characterised by frequent CRTC1/3-MAML2 fusions and a low clinical stage in all cases. Of the four histological features considered to be unusual in MEC, marked nuclear atypia, frequent mitoses (>10/10 high-power fields) and extensive necrosis were found independently of the fusion status, and were present in 3-5% of all cases. However, none of the cases showed overt keratinisation. On comparison, the Armed Forces Institute of Pathology and modified Healey grading systems downgraded tumours, the Brandwein system upgraded tumours, and the Memorial Sloan Kettering system provided a moderate means of assessment. CONCLUSION: Recognition of the histological diversity of MEC, its clinicopathological features and its associations with CRTC1/3-MAML2 fusions is helpful for an accurate diagnosis of this carcinoma.

Long-term efficacy of weekly paclitaxel therapy in unresectable primary squamous cell carcinoma of the thyroid.

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare disease with a poor prognosis. Because of its rarity, there is no established therapeutic regimen in unresectable cases. We report a case of PSCCT treated with weekly paclitaxel (wPTX) for more than 2 years. A 59-year-old woman presented to our hospital with a progressively enlarging neck mass. CT and MRI scans showed a tumor arising from the right lobe of the thyroid, invading the esophagus and trachea, as well as partially surrounding and invading the right common carotid artery. It was deemed unresectable. Biopsy revealed poorly differentiated squamous cell carcinoma. wPTX therapy was initiated. The patient achieved a partial response and is still undergoing treatment 28 months later. Adverse events included grade 3 neutropenia and grade 2 peripheral sensory neuropathy, which were manageable. Long-term wPTX therapy has been effective in this case of unresectable PSCCT.

Pleomorphic adenoma: detection of PLAG1 rearrangement-positive tumor components using whole-slide fluorescence in situ hybridization.

Pleomorphic adenoma (PA) consists of heterogeneous histological architecture mixed with epithelioid and mesenchymal forms. Various types of epithelial or myoepithelial malignancies arise from PA, but sarcomas are extremely rare. A human androgen receptor gene (HUMARA) clonality assay has suggested that PA is clonal in nature. However, clonality of various tumor components of PA would be difficult to determine with this assay. In addition, the results obtained should be carefully interpreted. PLAG1 rearrangements are considered a good molecular marker for neoplasticity in PA. We aimed to clarify the neoplasticity of the various tumor components present in PA using whole-slide fluorescence in situ hybridization (FISH). Five PA cases positive for PLAG1 rearrangements were examined. Using an immunohistochemistry panel, cell components in PA were classified into eight cell types. To precisely localize PLAG1 rearrangement-positive cell components at the cellular level, sequential retrieval of whole-slide imaging (WSI) data of HE histology and FISH for PLAG1 rearrangement was carried out. PLAG1 rearrangements were detected in ductal cells, myoepithelial spindle cells, myoepithelial oncocytic cells, myoepithelial plasmacytoid cells, and mesenchymal chondroid cells, but not in mesenchymal lipid cells, mesenchymal fibrous cells, or vascular endothelial cells. Immunohistochemical PLAG1 expression was restricted to cell components harboring PLAG1 rearrangements.The results of the present study indicate that ductal and myoepithelial, chondroid cells are neoplastic but lipid, fibrous, and endothelial cells are not. PLAG1 immunohistochemistry is useful in discriminating neoplastic from non-neoplastic cell components. These findings may be important for elucidating tumorigenesis and the process of malignant transformation in PA.

Pulmonary Tumor Thrombotic Microangiopathy Secondary to Extramammary Paget's Disease: An Autopsy Case Report and Literature Review.

Pulmonary tumor thrombotic microangiopathy is a fatal disease secondary to some malignant tumors, such as gastric cancer, esophageal cancer, and pancreatic cancer. A 61-year-old man presented to our clinic with a red plaque with erosion on his scrotum and was diagnosed with extramammary Paget's disease. Seven years after the initial diagnosis, multiple bone metastases were discovered, and he was started on oral administration of tegafur/gimeracil/oteracil. Two years after beginning the oral drug administration, the patient complained of dyspnea. A chest CT scan showed ground-glass opacity. Pulmonary artery blood cytology revealed carcinoma cells. He was diagnosed with pulmonary tumor thrombotic microangiopathy. At 9 days after the diagnosis, he died of circulatory and respiratory failure. The autopsy revealed microscopic metastatic tumor emboli in multiple pulmonary vessels with fibrin thrombus, which confirmed the earlier cytologic diagnosis. Observations in our case were consistent with the typical pattern of this pathology in the lung with multiple metastases. Pulmonary tumor thrombotic microangiopathy with a primary disease of cutaneous malignancy is extremely rare. Here, we report a rare case of pulmonary tumor thrombotic microangiopathy secondary to extramammary Paget's disease with a literature review.