Nobuo Kanazawa

Expression of bcl‐6 protein in normal skin and epidermal neoplasms

Bcl‐6 protein is a recently identified novel transcription factor whose deregulated expression is associated with diffuse large B cell lymphomas. It was recently shown by us that the protein is located in germinal center B cells and their neoplastic counterparts. In the present study, the expression of bcl‐6 protein on normal epidermlis, benign, and malignant tumors originating from epidermal cells, and squamous cell carcinoma (SCC) cell lines are investigated. With the use of Immunohistochemistry., bcl‐6 protein was shown to stain intensely on normal prickle cells, but none to only slightly on epidermal basal cells. Papillomas and keratoacanthomas copied their normal counterparts in the mode of expression. Various levels of expression were found on seborrheic keratoses, while the expression level on basal cell epithellomas was low. Pecullariy, eccrine poromas and undifferentiated spindle‐shaped basal cell epithellomas wen totelly unstained. Squamous cell carcinomas showed a variety of expression levels, while two undifferentiated spindle‐shaped carcinomas and one undifferentiated SCC cell line remained unstained. These results suggest that the expression of bcl‐6 protein may be associated with morphological differentiation in normal and neoplastic epidermal cells.

Microsatellite‐unstable mucinous colorectal carcinoma occurring in the elderly: Comparison with medullary type poorly differentiated adenocarcinoma

Mucinous carcinoma and poorly differentiated adenocarcinoma of the large intestine have a high frequency of microsatellite instability, and their occurrence increases gradually with age. To elucidate the clinicopathological and immunohistochemical features of microsatellite‐unstable mucinous carcinoma and compare the tumor with medullary type poorly differentiated adenocarcinoma, the clinicopathological status and expression of mucin core and hMLH1 proteins were studied in 15 microsatellite‐unstable and 20 microsatellite‐stable mucinous colorectal carcinomas occurring in elderly patients, and compared with 23 cases of medullary type poorly differentiated adenocarcinoma in which 21 cases were microsatellite‐unstable. Thirteen (87%) of 15 microsatellite‐unstable carcinomas exhibited absent hMLH1 expression compared with three (15%) of 20 microsatellite‐stable carcinomas (P < 0.01). The proportion (87%) of positive MUC5AC expression in microsatellite‐unstable mucinous carcinoma was significantly higher than that (45%) in microsatellite‐stable mucinous carcinoma (P = 0.01). Compared with microsatellite‐stable mucinous carcinoma, microsatellite‐unstable mucinous carcinomas were significantly associated with a proximal location, intra‐ and peritumoral inflammatory cell infiltration, frequent MUC5AC expression, a low incidence of lymph node metastasis and absent hMLH1 protein expression, which is not different to medullary type poorly differentiated adenocarcinoma except for MUC2 expression and age‐related occurrence. These results suggest that microsatellite‐unstable mucinous carcinoma occurring in the elderly shares clinicopathological and molecular features with medullary type poorly differentiated adenocarcinoma and that microsatellite instability with absent hMLH1 expression plays an important role in the development of these two carcinomas.

Polypoid prolapsing mucosal folds with diverticulosis and colonic muco-submucosal elongated polyps

Background:  In 1991, Kelly first reported the presence of red or brown mucosal protrusions or polyps associated with diverticular disease and described this syndrome as ‘polypoid prolapsing mucosal folds in diverticular disease.’ In 1994, Matake et al. independently reported several long mucosal intraluminal protrusions as ‘colonic muco‐submucosal elongated polyps.’ The purpose of the present study is to address the relationship between the two syndromes.

Intermittent Claudication Caused by Small Aorta Syndrome: A Case Report and Review of Literature

Aortoiliac arterial steno-occlusions in young or middle-aged patients are relatively rare and have been reported in the literature as small aorta syndrome (SAS) or hypoplastic aortoiliac syndrome. We report the case of a 48-year-old Japanese woman with intermittent claudication caused by SAS. We performed left iliofemoral bypass grafting with a Dacron graft via a retroperitoneal approach. Bypass grafts, endarterectomy, and sympathectomy have been used for surgical management. Given that post-procedural event rates are higher for SAS than for other common atherosclerotic diseases, patients with SAS should be closely followed up after surgery.