Liver biopsy in the post-hepatitis C virus era in Japan.

In Japan, liver biopsies were previously crucial in evaluating the severity of hepatitis caused by the hepatitis C virus (HCV) and diagnosing HCV-related hepatocellular carcinoma (HCC). However, due to the development of effective antiviral treatments and advanced imaging, the necessity for biopsies has significantly decreased. This change has resulted in fewer chances for diagnosing liver disease, causing many general pathologists to feel less confident in making liver biopsy diagnoses. This article provides a comprehensive overview of the challenges and potential solutions related to liver biopsies in Japan. First, it highlights the importance of considering steatotic liver diseases as independent conditions that can coexist with other liver diseases due to their increasing prevalence. Second, it emphasizes the need to avoid hasty assumptions of HCC in nodular lesions, because clinically diagnosable HCCs are not targets for biopsy. Third, the importance of diagnosing hepatic immune-related adverse events caused by immune checkpoint inhibitors is increasing due to the anticipated widespread use of these drugs. In conclusion, pathologists should be attuned to the changing landscape of liver diseases and approach liver biopsies with care and attention to detail.

Change in Main Histological Type of Invasive Breast Cancer From Ductal to Lobular Carcinoma by Neoadjuvant Chemotherapy.

We present a case study of breast cancer initially diagnosed as invasive ductal carcinoma (IDC), which subsequently substituted into invasive lobular carcinoma (ILC) following neoadjuvant chemotherapy (NAC). A 61-year-old woman presented with a palpable breast lump, and histological examination through core needle biopsy (CNB) confirmed the presence of IDC. After a 6-month course of NAC, the patient achieved a clinically complete response (cCR) and underwent mastectomy. The surgical specimen showed no detectable tumor upon palpation, but microscopic analysis revealed a highly infiltrative growth of poorly-cohesive small atypical cells in the original tumor area. Immunohistochemical staining demonstrated that the tumor cells were negative for E-cadherin, leading to a diagnosis of ILC. To address the histological discrepancy before and after NAC, we re-evaluated the initial CNB using E-cadherin immunohistochemistry. While most tumor cells were E-cadherin positive, a small area displaying scirrhous subtype-like morphology exhibited E-cadherin negativity. Consequently, we revised the diagnosis to mixed IDC-ILC. The differential chemosensitivity between IDC and ILC may provide insight into this phenomenon.

Malignant pleural mesothelioma in a patient with pneumothorax: A cumbersome subtype both clinically and pathologically.

Here, we report a case of malignant pleural mesothelioma (MPM) that was very difficult to diagnose. A 62-year-old woman with a surgical history of recurrent bilateral pneumothorax was admitted to our hospital with severe dysphagia. Computed tomography (CT) detected stenosis in the lower esophagus. Immunohistochemical examination of a biopsy sample from the stenotic region was suggestive of MPM. Chemotherapy was initiated, but the patient soon weakened and died. Autopsy revealed atypical cells, identical to those seen in the biopsy sample which had spread into the stenotic esophagus and entire thoracic cavity. Although neither pleural thickening/nodules nor asbestos bodies were observed, we finally diagnosed the tumor as a biphasic-type MPM. We re-examined previous surgical specimens of pneumothorax and acknowledged foci of bland mesothelial cell proliferation which had the same pathological findings as tumor cells at autopsy. The lack of asbestos exposure and pleural thickening, an initial manifestation of pneumothorax, and faint cytological atypia prevented an early diagnosis. In cases of recurrent pneumothorax in elderly patients, MPM should be included in the differential diagnosis.

Probe-Based Confocal Laser Endomicroscopy Using Acrinol as a Novel Dye Can Be Used to Observe Cancer Nuclei of Bladder Carcinoma In Situ.

Background: Cystoscopy using white light is a standard procedure for diagnosing bladder cancer; however, white light can result in missed lesions that are present, but not visible, such as in cases of carcinoma in situ (CIS). In this case report, we describe observing the nuclei of urothelial carcinoma cells in situ that were not visible with cystoscopy under white light using probe-based confocal laser endomicroscopy (pCLE) with acrinol and fluorescein during transurethral resection of a bladder tumor (TURBT). Case Presentation: A 59-year-old male with a medical history of neurogenic bladder dysfunction with multiple bladder diverticula was referred to the urology department for gross hematuria. TURBT was performed with the assistance of pCLE, using acrinol as a novel dye. Standard cystoscopy under white light could not detect any bladder tumor; however, pCLE using acrinol could detect the abnormal nuclei of bladder CIS. Subsequent histopathologic analysis of the specimen confirmed a diagnosis of bladder CIS. To our knowledge, this is the first reported case of bladder CIS diagnosed with the assistance of pCLE using acrinol in a patient undergoing a TURBT. Conclusion: pCLE using acrinol as a novel dye can help observe the cancerous nuclei of bladder CIS that cannot be detected using conventional cystoscopy under white light. Therefore, pCLE using acrinol is one possible modality for performing an optical biopsy during TURBT.

Chondroblastoma of trapezium with metacarpal involvement.

Chondroblastomas typically affect the epiphysis of the long bones in young patients, and only rarely occur in the elderly >70 years. Approximately 10% to 20% of chondroblastomas are located in the small bones of the hands or feet, however, they are rare in the carpal bones. Chondroblastoma is a benign tumor, but it may show not only aggressive clinical course but also pulmonary metastases. We report a case of chondroblastoma in a 75-year-old woman that originated in the right trapezium, involving the proximal half of the first metacarpal. She had noticed a mass in her right wrist for approximately 1 year before presenting to the hospital. Radiologically, a large lytic tumor was observed in the right trapezium, with marked expansion of the cortex. On magnetic resonance imaging and computed tomography, the tumor extended from the trapezium into the proximal half of the first metacarpal. Resection of the trapezium and a half of the first metacarpal was performed. Histologically, typical chondroblastoma with small foci of secondary aneurysmal bone cyst was noted. This is an unusual case of chondroblastoma, originating in the carpal bones of an elderly individual, and involving adjacent bone. Benign chondroblastomas of unusual sites may show locally aggressive features, and benign chondroblastomas may occur in elderly persons.

Characterization of thermostable native alkaline phosphatase from an aerobic hyperthermophilic archaeon, Aeropyrum pernix K1.

This paper reports the characterization of an alkaline phosphatase (AP) from an aerobic hyperthermophilic Archaeon Aeropyrum pernix K1. The native AP was purified into homogeneity. The enzyme is predicted as a homodimeric structure with a native molecular mass of about 75 kDa and monomer of about 40 kDa. Apparent optimum pH and temperature were estimated at 10.0 and above 95 degrees C, respectively. Magnesium ion increased both the stability and the activity of the enzyme. A. pernix AP has been demonstrated as a very thermostable AP, retaining about 76% of its activity after being incubated at 90 degrees C for 5.5 h and 67% of its activity after being incubated at 100 degrees C for 2.5 h, respectively, under the presence of Mg(II). Enzyme activity was increased in addition of exogenous Mg(II), Ca(II), Zn(II), and Co(II).