Reduced expression of hMLH1 and hMSH2 gene products in high-grade hepatocellular carcinoma.

We performed an immunohistochemical analysis of 2 major DNA mismatch repair proteins, human Mut L homologue-1 (hMLH1) and human Mut S homologue-2 (hMSH2), in hepatocellular carcinoma (HCC) using 33 biopsied and 58 surgically resected specimens, as well as 30 samples from non-cancerous livers. In well-differentiated HCCs, the immunoreactivity for these antigens was well preserved, and the staining intensity was stronger compared to the surrounding liver tissues. However, among 41 moderately-differentiated and 9 poorly-differentiated HCCs of the resected cases, hMLH1- and hMSH2-positive cells were significantly reduced in 19 (38%) and 9 (18%) cases, respectively. In 9 resected tumors, the expression of both of these antigens was reduced. Moreover, in 41 tumors of differing histological grades, 10 and 5 tumors for hMLH1 and hMSH2, respectively, contained a less-differentiated area with a reduced number of immunoreactive cells. The samples from non-cancerous biopsied liver and fetal autopsy tissue were well immunostained for both hMLH1 and hMSH2. We confirmed in this series that the hMLH1 and hMSH2 defect did commonly occur in high-grade HCCs, and that it might play a role in tumor progression.</p

Tracheal Stenosis Caused by Unnoticed Foreign Bodies

We describe an extremely rare case of tracheal stenosis caused by unnoticed microscopic fiber-like foreign bodies. A 66-year-old woman complained of dyspnea with inspiratory stridor. Magnifying electroendoscopy and computed tomography revealed stenosis involving the entire circumference of the tracheal lumen. Tracheotomy and biopsy were performed. Histologically, the lesion showed chronic inflammation with a deposition of fiber-like foreign bodies. The patient had no history of trauma or inhalation injury, but had undergone intratracheal intubation on 4 occasions. The lesion was incised using semiconductor laser photoresection, and the postoperative course was good. To the best of our knowledge, this represents the first report in the English literature of tracheal stenosis caused by unnoticed foreign bodies. The origin of these fiber-like foreign bodies remains unclear but might be related to chronic inflammation resulting from intratracheal intubations

A case of mucinous adenocarcinoma of the duodenum and literature review of 16 cases reported in Japan

　Primary mucinous adenocarcinoma of the duodenum is rare. Here we report a case we recently encountered, and we review 16 cases reported in Japan. An 82-year-old Japanese woman was admitted to our hospital complaining of abdominal pain and heartburn. An endoscopic examination revealed a Type 2 tumor in the descending limb of the duodenum, and endoscopically obtained specimens revealed a poorly differentiated adenocarcinoma. We performed a curative pancreatoduodenectomy with lymph node resection, and the surgical specimen revealed that the duodenum was the primary site of the mucinous adenocarcinoma. The patient is currently alive ＞ 1 year after the operation without any evidence of recurrence. Of the 16 patients reviewed, all patients had advanced tumors those depth were T3-T4. 9 patients had lymph node metastasis and 4 patients had peritoneal dissemination at the time of surgery. Since mucinous adenocarcinoma of the duodenum is often progressive cancer at a diagnosis, which is tend to have a worse prognosis than other histological types

Aberrant nuclear beta-catenin expression in the spindle or corded cells in so-called corded and hyalinized endometrioid carcinomas. Another critical role of the unique morphological feature

Corded and hyalinized endometrioid carcinoma (CHEC), showing spindle and/or corded (SPICO) cells often in the background of hyalinized stroma, is a rare variant of uterine endometrioid carcinomas. The aim of our study was to explore the status of cell-adhesion molecules (beta-catenin, Ecadherin) in CHECs and to survey whether immunostains for beta-catenin and p53 can help to distinguish CHECs from their morphological mimics: malignant mixed mullerian tumors (MMMTs) and uterine tumors resembling ovarian sex-cord tumors (UTROSCTs). Immunohistochemistry was performed and scored for each element as follows: 0: negative, 1+: 30%. The SPICO patterns were classified as spindle/fusiform; 3, corded; 1, and both; 2. SPICO components consisted of <10%: 4, 10-30%: 1, >30%: 1. Five contained squamous components. In SPICO elements of all CHECs, nuclear beta-catenin expression (score: 1+; 1, 2+; 2, 3+; 3) and complete loss of membranous expression of E-cadherin was observed. In contrast, comparable components (sarcomatous ones for eight MMMTs or sex-cord-like ones for six UTROSCTs) showed no nuclear positivity for beta-catenin. p53 expression was observed in SPICO (64.7%), sarcomatous (87.5%), and sex-cord-like (50%) components, and sarcomatous areas of most MMMTs notably showed diffuse and intense staining. Sequence analysis of PCR amplification products of exon 3 of the beta-catenin gene revealed mutation in all cases, except two lacking SPICO components represented on microdissected areas. Our results suggest that alterations in beta-catenin/E-cadherin complex play a critical role in SPICO features. Immunostain for beta-catenin and p53 is a promising approach for distinguishing CHECs from MMMTs and UTROSCT

Ovarian stromal cells as a source of cancer-associated fibroblasts in human epithelial ovarian cancer: A histopathological study.

Fibroblasts are a major component of cancer tissue and known to contribute to cancer progression. However, it remains unknown whether they are derived from local fibroblasts or of other origin. This study was designed to identify the contribution of local stromal cells to cancer stroma in human epithelial ovarian cancer. Seventy-six cases of surgically resected primary ovarian carcinoma (48 cases confined to the ovaries and 28 cases with distant metastases) and 17 cases of secondary ovarian tumor (e.g. colon cancer metastasized to the ovary) were enrolled in this study. The tissues were immunostained for forkhead box protein L2 (FOXL2), a transcription factor crucial for ovarian development and function, and markers for cancer-associated fibroblasts (CAFs) and inflammatory cells. Under normal condition, FOXL2 expression was restricted to ovarian stromal cells and some other types of cells in female genital tracts and never found in other sites of the body. FOXL2-positive cells were found in all primary and secondary tumors in the ovary, and were the dominant stromal cells in most cases. In contrast, only a few FOXL2-positive cells were found in peritoneal seeding sites of four serous carcinoma cases, and all the other tumors at extraovarian sites had no FOXL2-positive cells. FOXL2-positive cells in the ovarian lesion variably expressed CAFs markers, such as alpha-smooth muscle actin and fibroblast activating protein, as determined by double immunostaining. Background inflammation, but not histological subtype or origin of the neoplasm seemed to correlate with the proportion of FOXL2-positive cells. These results suggest that ovarian stromal cells are the main source of cancer stroma in the ovary but do not seem to move to distant sites via circulation together with tumor cells. Our results also support the hypothesis that cancer-associated fibroblasts may originate locally, which was previously demonstrated using animal models