Jin Tanahashi

Human intestinal spirochetosis in Japan; its incidence, clinicopathologic features, and genotypic identification

Human intestinal spirochetosis is a common condition in Western countries, but is not well recognized in Japan. To demonstrate the incidence and clinicopathologic findings of human intestinal spirochetosis in Japan, we retrospectively investigated biopsy, and endoscopically or surgically resected specimens of the large intestine. Among a series of 2556 samples, 11 cases of human intestinal spirochetosis were detected (0.4%). Together with additional nine cases sporadically found, 20 cases of human intestinal spirochetosis were subjected to molecular detection of two strains of spirochetes (Brachyspira aalborgi and Brachyspira pilosicoli) by amplifying species-specific portion of 16S ribosomal RNA and NADH oxydase gene by polymerase chain reaction. B. aalborgi was detected in all cases examined, three of which revealed dual infection of both species. Our results suggest that human intestinal spirochetosis infection is relatively rare, and B. aalborgi is the most prevalent species in Japan. Most of human intestinal spirochetosis were asymptomatic, although symptomatic in exceptional cases. In addition, we emphasize a usefulness of immunostaining with anti-Treponema pallidum and anti-Mycobacterium bovis polyclonal antibodies for detecting the spirochetes.

Duodenal gangliocytic paraganglioma treated with endoscopic hemostasis and resection

Gangliocytic paragangliomas are exceedingly rare tumors that arise in close proximity to the papilla of Vater. There are few reports of the endoscopic resection of duodenal gangliocytic paraganglioma. A 61-year-old woman was admitted with a complaint of melena. Endoscopic examination revealed a pedunculated submucosal tumor with erosion in the third portion of the duodenum. Hemostasis, using a gold probe, was performed. Nine days later, we successfully resected the tumor, using endoscopic polypectomy. To determine the depth of tumor invasion, endoscopic ultrasonography was used. The size of the tumor was 3.0 × 2.5 × 1.0 cm. A total of 25 cases of duodenal gangliocytic paraganglioma have been reported in Japan. Generally, this tumor is considered benign. However, resection was performed in many patients because preoperative diagnosis was impossible. In Japan, no previous studies have reported using endoscopic hemostasis, to our knowledge. Our patient is the fourth in Japan to be treated by endoscopic resection. We report on our patient, with a review of the literature.

Sitafloxacin Activity against Helicobacter pylori Isolates, Including Those with gyrA Mutations

ABSTRACT Sitafloxacin showed MICs of less than or equal to 0.5 μg/ml against 105 isolates of Helicobacter pylori, including 44 isolates with mutations in the gyrA gene. The highest MICs for garenoxacin and levofloxacin were 8 and 64 times, respectively, higher than the highest MICs observed for sitafloxacin.

A case of cutaneous myoepithelial carcinoma

Background:  Cutaneous myoepithelioma, both benign and malignant, is a rare neoplasm composed of neoplastic myoepithelial cells showing diverse histopathological features, and criteria for discriminating benign or malignant have not been fully clarified.

Mutational analysis of Wnt signaling molecules in ameloblastoma with aberrant nuclear expression of β-catenin

BACKGROUND To clarify the genetic background of ameloblastoma, expression of beta-catenin, and mutational status of genes involved in Wnt signaling pathway were investigated. METHODS We analyzed beta-catenin and cyclin D1 in 18 cases of ameloblastoma by immunohistochemical staining, and searched for mutations in CTNNB1 (gene for beta-catenin), APC, AXIN1, and AXIN2 by polymerase chain reaction (PCR) and direct sequencing method. RESULT We detected membranous and occasionally cytoplasmic expression of beta-catenin in 16 of 18 cases (89%), and nuclear expression of beta-catenin principally in the peripheral columnar cells in 11 of 18 cases (61%). In nine of the 18 cases (50%), we detected the expression of cyclin D1 principally in the peripheral columnar cells. However, there was no correlation between nuclear expressions of beta-catenin and cyclin D1. No missense mutations were found in CTNNB1, APC, AXIN1, and AXIN2 in all cases except for silent mutation and already-known single nucleotide polymorphism. CONCLUSION Mutations in CTNNB1, APC, AXIN1, and AXIN2 are not implicated in nuclear accumulation of beta-catenin, and that the expression of cyclin D1 is accelerated independently of beta-catenin in ameloblastomas. Other Wnt signaling members or alternative pathways involved in the degradation of beta-catenin should be subject of further investigation.

Solitary fibrous tumor of the thyroid gland: Report of two cases and review of the literature

Presented herein are the first two Japanese cases of solitary fibrous tumor (SFT) of the thyroid gland. The patients were 64‐ and 41‐year‐old men, who underwent hemithyroidectomy for thyroid tumors. Histopathologically, the tumors were well circumscribed, and were composed of spindle cells, collagen bundles and entrapped thyroid follicles. Spindle cells and collagen bundles were mostly in a patternless arrangement with an admixture of hypo‐ and hypercellular areas. Proliferating spindle cells were bland, slender, and occasionally wavy without any atypia and increased mitotic figures. Immunohistochemically, they were strongly positive for CD34, CD99, and bcl‐2, but negative for epithelial membrane antigen, keratin, thyroglobulin, calcitonin, thyroid transcription factor‐1, α‐smooth muscle actin, desmin, S‐100 protein and CD117. Based on these findings, the two patients were diagnosed as having thyroid SFT. Neither local recurrence nor metastasis has been observed in 5 years in patient 1 or in 4 years in patient 2. Thyroid SFT is extremely rare, and only 20 cases have been reported in the English‐language literature including hemangiopericytoma. Although recurrence or metastasis has not been described in any reported cases, the clinical behavior of SFT is still undetermined, therefore long‐term follow up seems necessary at present.

Merkel cell carcinoma co-existent with sebaceous carcinoma of the eyelid

Merkel cell carcinoma is occasionally associated with other types of cutaneous malignancies including squamous cell carcinoma, basal cell carcinoma and lentigo maligna. We report a case of Merkel cell carcinoma co‐existent with sebaceous carcinoma in the right upper eyelid of a 61‐year‐old Japanese man. Histopathologically, the resected tumor consisted of three nodules located in the tarsal plate, showing two distinct histopathological types. Two nodules were Merkel cell carcinoma and located in the proximal part of the palpebral conjunctiva. The third was sebaceous carcinoma located in the distal transitional zone between the epidermis and the conjunctiva. No features of transition between these two components were noted. Metastatic deposits were identified in the regional lymph nodes, which solely consisted of Merkel cell carcinoma without sebaceous carcinoma. This is the first report of such co‐existent lesions.

Comparison of the efficacy of irsogladine maleate and famotidine for the healing of gastric ulcers after Helicobacter pylori eradication therapy: a randomized, controlled, prospective study.

Abstract Objective. Helicobacter pylori eradication therapy alone cannot heal gastric ulcers in Japanese patients. Irsogladine has previously been shown to accelerate the healing of gastric ulcers after H. pylori eradication therapy. And we previously reported that histamine H2 receptor antagonists inhibit gastric ulcer relapse after H. pylori eradication therapy. We therefore compared the efficacy of irsogladine with famotidine as appropriate treatments for ulcers after eradication therapy. Methods. Gastric ulcer patients with H. pylori infection (n = 119) were randomized to treatment with irsogladine 4 mg/day (n = 60) or famotidine 40 mg/day (n = 59) following 1-week H. pylori eradication therapy. After treatment, assessments of gastric ulcer healing were performed. Results. The ulcer healing rates in patients receiving irsogladine and famotidine were 85.2% (46/54) and 79.6% (43/54), respectively, and were not significantly different (p = 0.4484). In the famotidine group, the healing rate was significantly lower in patients who drink alcohol than in those who do not (60.0% vs. 91.2%; p = 0.0119). However, in the irsogladine group the healing rate did not differ between patients who drink alcohol and those who do not. Furthermore, the healing rate in smokers was significantly higher in the irsogladine group (88.0%) than in the famotidine group (59.1%) (p = 0.0233). Conclusions. Irsogladine and famotidine are both acceptable in treatment after H. pylori eradication therapy in gastric ulcer patients. Findings also suggest that irsogladine is more beneficial than famotidine in patients who drink alcohol and smoke.

Pulmonary myoepithelial carcinoma resembling matrix-producing carcinoma of the breast: case report and review of the literature

Tanahashi J, Kashima K, Daa T, Yada N, Tanaka K‐I, Kawano Y, Yokoyama S. Pulmonary myoepithelial carcinoma resembling matrix‐producing carcinoma of the breast: case report and review of the literature. APMIS 2010; 118: 401–6.

A Case of Sebaceoma With Extensive Apocrine Differentiation

Apocrine differentiation is a rare event in sebaceoma, and only 3 cases have been reported. We report a case of sebaceoma with extensive apocrine differentiation on the scalp in a 73-year-old Japanese woman. The resected tumor was located entirely within the dermis and subcutis as a well-circumscribed, lobulated, solid, and partially cystic mass, measuring 35 mm at the largest diameter. Histopathologically, it was composed of uniform basaloid cells with clusters of sebocytes, squamous islands of ductal structures, and apocrine cells with apparent decapitation secretion. Nuclear atypia of all types of cells was inconspicuous, and mitotic figures were infrequent. We considered the lesion to be a sebaceoma with apocrine differentiation.