Long-term outcomes of stapes surgery.

OBJECTIVE: Hearing improvement following stapes surgery is generally good; however, we sometimes encounter patients where hearing loss gradually progresses over the long term. In this study, we investigated the causes of hearing loss in these cases. METHODS: A total of 30 ears from 23 patients, who underwent stapes surgery at Kitasato University Hospital from 2001 to 2021 and were followed up for ≥5 years, were included in the study. Changes in air conduction (AC) and bone conduction (BC) thresholds were measured, and hearing evaluation was performed by calculating the air-bone gap (ABG) at the mean of 4 frequencies. Cases with a postoperative ABG of ≤10 dB at 6 months after surgery were classified into the following groups according to their hearing changes at 5 years after surgery: Group A (no ABG increase of ≥10 dB and no AC threshold increase of ≥10 dB) and Group B (an ABG increase of ≥10 dB and an AC threshold increase of ≥10 dB). In groups A and B, we examined factors affecting long-term postoperative results. In addition, the patients who underwent reoperation were examined. RESULTS: The AC thresholds 6 months and 5 years after surgery decreased significantly compared with those before surgery (p  <  0.01); however, the BC thresholds 6 months and 5 years after surgery did not vary significantly from those before surgery (p  >  0.05). Group A included 16 ears from 13 patients (53.3%), and Group B included 3 ears from 3 patients (10.0%). There were no significant differences in age, sex, surgical method, piston type, piston length, presence of incudostapedial joint subluxation, computed tomography findings, and preoperative ABGs between groups A and B (p  >  0.05). A total of 6 reoperations were performed in 3 ears from 3 patients, and there were 5 operations with the platinotomy hole to be closed by bone regrowth and 3 operations with the narrowed long process of the incus. CONCLUSION: In 10.0% of the patients who underwent stapes surgery, the ABG improved 6 months after surgery; however, the AC threshold and ABG increased 5 years after surgery. Our findings suggested that piston displacement and the platinotomy hole to be closed by bone regrowth are possible causes of hearing loss in cases where hearing loss progresses in the long term after stapes surgery.

Detection of circulating fungal DNA by polymerase chain reaction in a fatal case of Cunninghamella bertholletiae infection.

INTRODUCTION: Cunninghamella bertholletiae although rarely causing mucormycosis, is responsible for the highest mortality among mucormycetes. The diagnosis of mucormycosis is challenged by the absence of specific biomarkers. Herein, we report a fatal case of C. bertholletiae infection and detection of its DNA in the serum by polymerase chain reaction (PCR). PRESENTATION OF CASE: A 23-year-old male with refractory osteosarcoma was admitted with multiple lung metastases. He was on oral voriconazole prophylaxis after pulmonary aspergillosis. He suffered from fever during temporary neutropenia following chemotherapy and showed several neurological and respiratory symptoms. Despite liposomal-amphotericin B administration, the symptoms rapidly progressed, and he died five days after the onset of neurological symptoms.We retrospectively evaluated the filamentous fungus isolated after his death from gastric juices. Based on the sequence of the internal transcribed spacer (ITS) region we identified the fungal isolate as C. bertholletiae. A 146-bp portion of the D1/D2 region was quantified by quantitative-PCR using DNA extracted from the serum. C. bertholletiae DNA load in the serum was 18.0 copies/µL on the day of onset of neurological symptoms, with the highest (101.0 copies/µL) on the day of his death. DISCUSSION: Detection of circulating DNA of mucormycetes in the blood would greatly enhance the diagnosis of mucormycosis. Rapid diagnosis might alleviate mortality due to mucormycosis. CONCLUSION: The present case-report suggests that the quantification of C. bertholletiae DNA in the serum could be useful for the diagnosis and evaluation of mucormycosis pathogenesis in patients.

Identification of a novel BOC-PLAG1 fusion gene in a case of lipoblastoma.

Lipoblastoma is a rare benign adipose tissue tumor that occurs mostly in infants and children. Histological diagnosis of lipoblastoma is sometimes difficult because it closely resembles other lipomatous tumors. The detection of PLAG1 gene rearrangement is useful for the diagnosis of lipoblastoma. Four PLAG1 fusion partner genes are known in lipoblastoma: HAS2 at 8q24.1, COL1A2 at 7q22, COL3A1 at 2q32, and RAB2A at 8q12. Herein, we describe a novel fusion gene in a case of lipoblastoma of left back origin. We identified a potential PLAG1 fusion partner using 5' rapid amplification of cDNA ends, and sequence analysis revealed the novel fusion gene, BOC-PLAG1. The BOC-PLAG1 fusion transcript consists of the first exon of the BOC gene fused to exon 2 or exon 3 of the PLAG1 gene. PLAG1 expression was found to be 35.7 ±â€¯2.1 times higher in the tumor specimen than in human adipocytes by qRT-PCR. As a result of the translocation, the constitutively active promoter of BOC leads to PLAG1 overexpression. The identification of the BOC-PLAG1 fusion gene will lead to more accurate diagnosis of lipoblastoma.