S100A8 and S100A9 are associated with endometrial shedding during menstruation.

Matrix metalloproteinases (MMPs) and their major source, endometrial stromal cells (ESCs), play important roles in menstruation. However, other mechanisms in endometrial shedding may be unexplored. This study focused on four proteins: S100A8 and S100A9 (alarmins) are binding partners and induce MMPs, MMP-3 cycle-dependently plays a key role in the proteolytic cascade, and CD147, which has S100A9 as its ligand, induces MMPs. Immunostaining for these proteins was performed on 118 resected specimens. The percentage and location of each positive reaction in ESCs were measured and compared using Image J. The influence of leukocytes on S100A8 or S100A9 immunopositivity was also examined. From the premenstrual phase, S100A8 and MMP-3 began to have overlapping expressions in ESCs of the superficial layer, and ESC detachment was found within these sites. S100A9 was expressed from the late secretory phase and CD147 already from earlier. Later, the expression sites of S100A9 and CD147 included those of S100A8. Before menstruation, S100A8 or S100A9 expression was not affected by leukocytes. These results suggest that the local formation of S100A8/S100A9 complex, which occurs specifically in ESCs upon progesterone withdrawal, induces the local expression of MMP-3 and serves as a switch to the lysis phase.

A Case of Colonic Micropapillary Carcinoma with a High Frequency of Apoptosis.

Colorectal micropapillary carcinoma (MPC) exhibits aggressive biological characteristics, with empty spaces and reversed polarity, similar to the poorly differentiated clusters (PDCs) formed from detached cancer cells. Epithelial-mesenchymal transition, which is involved in the cancer cell acquisition of apoptosis resistance, is closely linked with histological findings of MPC, PDCs, and tumor buds (TBs), with MPC and TBs considered as apoptosis-resistant features. However, we encountered a case of colonic MPC with frequent apoptosis. We examined the case using immunohistochemistry. In many of the tumor glands (TGs) of the MPC, empty spaces and tumor cell detachment toward the gland interior were observed. Moreover, TG ruptures were scattered, with PDCs adjacent to them. Apoptosis occurred mainly at the TG and PDC peripheries in the middle and deep tumor layers, and transforming growth factor beta 1 (TGF-ß1) positivity was evident in those tumor cells. Cells positive for apoptosis-related M30 were distributed mainly in the deep layer with a significant PDC and TB presence. However, apoptosis and M30 positivity were low in the TBs. Non-tumorous bud components, especially those in the deep layer, had poor ability to promptly acquire apoptosis resistance. No nuclear ß-catenin positivity was found in any of the tumor cells. Apoptosis has the potential to reciprocally produce MPC, PDCs, and TBs, with TGF-ß1 involvement.

Hybrid Carcinoma of the Parotid Gland: An Extremely Rare Three Cases with an Immunohistochemical Analysis and a Review of the Literature.

Salivary hybrid carcinoma (HC) is defined as when two or more kinds of carcinoma exist at the same location in a single mass. We reestimated and examined three cases of salivary gland HC. Case 1 involved a 76-year-old male. Case 2 involved a 74-year-old female. Case 3 involved a 66-year-old male. Histologically, case 1 involved a combination of salivary duct carcinoma (SDC) and squamous cell carcinoma (SqCC). Immunohistochemically, the former was positive for gross cystic disease fluid protein (GCDFP)-15 and androgen receptor (AR). Case 2 involved a combination of SqCC and neuroendocrine carcinoma. Immunohistochemically the latter was positive for synaptophysin and neural cell adhesion molecule (NCAM). Case 3 involved a combination of SDC and epithelial-myoepithelial carcinoma (EMC). Immunohistochemically, the former was positive for GCDFP-15 and AR, whereas the inner cells of the latter were positive for cytokeratin 7, and the outer cells of the latter were positive for actin. Because of the transitional zone between SDC and EMC, it was speculated that high-grade SDC arose from low-grade EMC.

Periostin expression and its supposed roles in benign and malignant thyroid nodules: an immunohistochemical study of 105 cases.

BACKGROUND: Thyroid tumors are often difficult to histopathologically diagnose, particularly follicular adenoma (FA) and follicular carcinoma (FC). Papillary carcinoma (PAC) has several histological subtypes. Periostin (PON), which is a non-collagenous extracellular matrix molecule, has been implicated in tumor invasiveness. We herein aimed to elucidate the expression status and localization of PON in thyroid tumors. METHOD: We collected 105 cases of thyroid nodules, which included cases of adenomatous goiter, FA, microcarcinoma (MIC), PAC, FC, poorly differentiated carcinoma (PDCa), and undifferentiated carcinoma (UCa), and immunohistochemically examined the PON expression patterns of these lesions. RESULTS: Stromal PON deposition was detected in PAC and MIC, particularly in the solid/sclerosing subtype, whereas FA and FC showed weak deposition on the fibrous capsule. However, the invasive and/or extracapsular regions of microinvasive FC showed quite strong PON expression. Except for it, we could not find any significant histopathological differences between FA and FC. There were no other significant histopathological differences between FA and FC. Although PDCa showed a similar PON expression pattern to PAC, UCa exhibited stromal PON deposition in its invasive portions and cytoplasmic expression in its carcinoma cells. Although there was only one case of UCa, it showed strong PON immunopositivity. PAC and MIC showed similar patterns of stromal PON deposition, particularly at the invasive front. CONCLUSIONS: PON may play a role in the invasion of thyroid carcinomas, particularly PAC and UCa, whereas it may act as a barrier to the growth of tumor cells in FA and minimally invasive FC.

Nivolumab-induced liver injury with a steroid-refractory increase in biliary enzymes, in a patient with malignant mesothelioma: An autopsy case report.

This is the first autopsy report of hepatotoxicity from nivolumab immunotherapy for malignant mesothelioma. The increase in levels of biliary enzymes and randomly distributed endothelial damage were steroid-refractory, but second-line option was abandoned because of cachexia. Further discussions are needed regarding the customized management of immune-related toxicities.

A case of small hepatocellular carcinoma with malignant ductular reaction.

Herein reported is the unique case of a small hepatocellular carcinoma (HCC) with several foci of a minor (10% in area) component of "malignant ductular reactions". The patient was 51-year-old man who was a drinker. HBV/HCV were negative. The tumor was small (12×10×11 mm), solid, expansile and reddish-brown, and contained fibrous septa. The background was cirrhotic without alcoholic features. Histologically, the tumor was well differentiated HCC, and, besides the HCC, it contained several small foci consisting of the following four biliary epithelial elements: clusters of small cells (CSC), ductules (D), ductular hepatocytes (DH), and bile ducts (BD). The proportion of area was as follows: HCC 90%, CSC 3%, D 3%, DH 2%, and BD 2%. These non-HCC elements were intimately admixed and formed several foci that were characteristically located in the fibrous septa (FS), except for CSC which were situated among HCC cells close to FS. There were gradual merges between HCC and CSC, CSC and D, D and DH, and D and BD, respectively. Cells of CSC and D resembled rat oval cells. Cells of these four elements had atypical features regarded as malignant. Immunohistochemically (IHC), HCC were positive for arginase, HepPar1, and less frequently CK7. CSC were positive for CK7. D were positive for arginase, HepPar1, CK7, CK19, EMA, and EpCAM. DH were positive for arginase, HepPar1, and CK7. BD were positive for CK7, CK19, EMA, EpCAM and mucin. Although such tumors as this have been termed stem cell-related cancers, our case lacked definite evidence for stem cell origin in histology as well as in the IHC that showed negativity for KIT, CD34, and OCT3/4. The above findings suggest that CSC, D, DH and BD are analogous to the ductular reaction seen in hepatic inflammation. Therefore, we termed the phenomenon "malignant ductular reaction". It is suggested in the present tumor that at first only HCC developed, and then HCC cells in the interface with FS transformed to CSC, like a fetal ductal plate. Then, the CSC gave rise to D, which in turn led to DH and BD in FS, all findings of which are most likely sequential considering embryonic biliary development. The idea that the present tumor was at first D carcinoma and then D developed on one hand into CSC and HCC, and on the other into DH and BD seems possible, but its probability appears low because the vast majority of the present tumor had the phenotype of HCC.

Switching from first or second generation EGFR-TKI to osimertinib in EGFR mutation-positive NSCLC.

AIM: We evaluated the efficacy of a novel switch protocol for EGFR-TKIs for EGFR mutation-positive NSCLC. MATERIALS & METHODS: Clinical records were collected from the patients who had received one of two sequential combination strategies of EGFR-TKIs: Salvage use of osimertinib for T790M-mediated acquired resistance to an prior EGFR-TKI or switch use of osimertinib where an EGFR-TKI was switched to osimertinib before disease progression. RESULTS: Progression-free survival of osimertinib and time from the start of treatment until progression to osimertinib was comparable between the salvage use and switch use of osimertinib. CONCLUSION: Switch use of osimertinib seemed to produce improved efficacy for patients with activating EGFR mutations, because of the lack of patient selection via T790M.

A case of small well-differentiated hepatocellular carcinoma with marked lymphocytic infiltrate.

We herein report a case of well-differentiated small hepatocellular carcinoma (HCC) with severe lymphocytic infiltrate (SLI) in a 55-year-old male patient with HCV-related cirrhosis. The patient had been followed-up because of HCV-related cirrhosis. He was found to have two small nodules in S8 by imaging techniques, and he underwent S8 segmentectomy. The resected liver showed two small nodules. Both were encapsulated, well-defined, solid, reddish and expansive nodules with fibrous septa. They measured 8 × 8 mm and 15 × 10 mm, respectively. Histologically, both tumours were pure HCC; the smaller showed SLI with lymphocytes/HCC cells ratio over 20, while the larger showed mild lymphocytic infiltration with lymphocytes/HCC cells ratio of 0.8. The smaller HCC was well-differentiated (trabecular thickness <3) HCC-SLI with Edmondson II = I cytologic atypia, while the larger was moderately-differentiated (trabeculae >3) HCC (Edmondson II>III>I). Extremely well-differentiated Edmondson I HCC or adenomatous hyperplasia areas were seen in the periphery of both HCCs. The patterns of SLI could be classified into the following three: sinusoids (S) type, portal tract (PT) type, lymph follicle (LF) type. In S-type, lymphocytes were infiltrated between the trabeculae. In PT-type, SLI was found to arise from extension from already inflamed PT within HCC or neighboring PT. The HCC cells frequently exhibited moth-eaten or piece meal necrosis in PT-type. In LF-type, lymphocytes were activated, and nuclear dusts were noted. It appeared that LF-type has arisen from preexisting S-type and/or PT-type. We speculated that the entry of SLI was from S in S-type, from incorporated inflamed PT in PT-type, and from both in LF-type. The approximate overall positive ratios of lymphoid cells among inflammatory cells were as follows: CD20 50%, CD3 70%, CD4 50%, CD8 30%, CD138 3%, CD163 40%, granzyme B 2%, smooth muscle actin (SMA) 30%, CD31 30%, CD21 2%, S100 3%, bcl-2 10%, CK19 1%, CD10 1%, CD30 0%, CD56 0% and Ki67 labeling index = 5%. EBV-ISH and HPV IHC were negative. Interestingly, Kupffer cells had myofibroblastic antigen in addition to macrophage antigens, and stellate cells expressed macrophage antigens aside from myofibroblastic antigens. These data suggest that, in the present case, pan-B-cells, pan-T-cells, helper T-cells, cytotoxic T-cells, plasma cells, macrophages, Kupffer cells, stellate cells, myofibroblasts, fibroblasts, endothelial cells, dendritic cells, Langerhans cells, and toxic molecules may play roles in tumour immunology.

Clinical Characteristics and Long-Term Outcomes of Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) has various morphological and clinical features. A decade has passed since the previous survey of the epidemiological and clinical characteristics of Japanese HCM patients. The Aichi Hypertrophic Cardiomyopathy (AHC) Registry is based on a prospective multicenter observational study of HCM patients. The clinical characteristics of 42 ambulant HCM patients followed up for up to 5 years were investigated. The primary endpoint was major adverse cardiac events (MACE), defined as death, non-fatal stroke, admission due to congestive heart failure (CHF), or episodes of sustained ventricular tachycardia/fibrillation. The MACE-free survival during the 5-year follow-up period was 76% according to Kaplan-Meier analysis. HCM-related death occurred in 3 (7%) patients and SCD occurred in 2 (5%) patients. Additionally, 3 (7%) patients were admitted to the hospital due to CHF. Meanwhile, sustained VT was detected in one (2%) of the patients who received ICD implantation and subsequently terminated with antitachycardia pacing using an ICD. The patients with HCM exhibiting left ventricular outflow obstruction (HOCM) had a slightly lower MACE-free survival rate than those with neither HOCM nor dilated-HCM (dHCM) (71% versus 81%, log-rank P = 0.581). Furthermore, the patients with dHCM demonstrated a significantly lower MACE-free survival rate than those with neither HOCM nor dHCM (33% versus 81%, log-rank P = 0.029). In the AHC Registry targeting current Japanese HCM patients, we demonstrated that many HCM patients continue to suffer from MACE despite the development of various treatments for HCM.