A primary thymic adenocarcinoma with two components that traced distinct evolutionary trajectories.

Even though it is a rare subtype, identifying the genetic features of thymic adenocarcinoma is valuable for a multifaceted understanding of thymic epithelial tumors. We experienced a female patient with thymic adenocarcinoma associated with thymic cysts. The tumor consisted of a solid whitish lesion (lesion-1) and a large cystic lesion with small papillary nodules (lesion-2). Microscopically, lesion-1 exhibited poorly differentiated adenocarcinoma accompanying numerous inflammatory cell infiltrates, and lesion-2 (the nodules within the cystic lesion) exhibited enteric-type adenocarcinoma. Consistent with the histological difference, whole-exome sequencing revealed that these two components exhibited distinct genetic features, except for only a few shared mutations, including CDKN2A truncation. Lesion-1 exhibited microsatellite instability-high signature with high mutation burden, for which immune checkpoint inhibitors might apply; and lesion-2 exhibited whole-genome doubling with KRAS hotspot mutation. Our case presents novel genetic features of thymic adenocarcinoma and demonstrates that distinct mutational processes can be operative within a single tumor.

Properties of Achromobacter xylosoxidans highly resistant to aminoglycoside antibiotics.

We herein discovered a highly resistant clinical isolate of Pseudomonas aeruginosa with MICs to amikacin, gentamicin, and arbekacin of 128 µg/mL or higher in a drug sensitivity survey of 92 strains isolated from the specimens of Yoka hospital patients between January 2009 and October 2010, and Achromobacter xylosoxidans was separated from this P. aeruginosa isolate. The sensitivity of this bacterium to 29 antibiotics was investigated. The MICs of this A. xylosoxidans strain to 9 aminoglycoside antibiotics were: amikacin, gentamicin, arbekacin, streptomycin, kanamycin, neomycin, and spectinomycin, 1,024 µg/mL or ≥ 1,024 µg/mL; netilmicin, 512 µg/mL; and tobramycin, 256 µg/mL. This strain was also resistant to dibekacin. This aminoglycoside antibiotic resistant phenotype is very rare, and we are the first report the emergence of A. xylosoxidans with this characteristic.

A ciliated adenocarcinoma of the lung mimicking lung abscess and pneumonia.

This case report describes a 78-year-old man initially treated for pneumonia and lung abscess who was resistant to antimicrobial treatment and was eventually diagnosed with ciliated adenocarcinoma. Ciliated adenocarcinoma, a rare non-terminal respiratory unit (TRU)-type lung adenocarcinoma, presents a unique diagnostic challenge because of its similarity to pneumonia and lung abscesses. Morphologically, the ciliated adenocarcinoma in this case appeared to be a non-TRU type adenocarcinoma, with partial mucous epithelium, no visible extracellular mucus, thyroid transcription factor (TTF)-1 negativity, and mucin (MUC) 5AC positivity on immunostaining. The patient was considered to have ciliated adenocarcinoma based on the fact that the mucous epithelium was partial and extracellular mucus was not prominent. This case emphasizes the importance of considering malignancy in patients with non-resolving pulmonary infections.

18F-FDG PET/CT Findings of G-CSF-Producing Gallbladder Cancer.

ABSTRACT: We report a case of granulocyte colony-stimulating factor (G-CSF)-producing gallbladder cancer in a 64-year-old man. Contrast-enhanced CT showed an exophytic hypoattenuation mass with peripheral enhancement in the gallbladder. 18F-FDG PET/CT showed avid FDG uptake in the gallbladder mass and diffuse FDG uptake in the bone marrow. The patient was diagnosed with G-CSF-producing gallbladder cancer based on an elevated serum level of G-CSF and histological findings. G-CSF-producing tumors are associated with a poor prognosis because of rapid progression. Early and accurate diagnosis of G-CSF-producing tumors based on characteristic PET/CT findings is important to determine treatment strategies and improve prognosis of patients.

Chronic abruption-oligohydramnios sequence (CAOS) revisited: possible implication of premature rupture of membranes.

AIM: The pathogenic mechanism of chronic abruption-oligohydramnios sequence (CAOS) remains unknown, and there are no objective standards for diagnosis on imaging or using pathological evidence. We aimed to reconsider and clarify the true pathology of CAOS by integrating clinical, magnetic resonance imaging (MRI) and histopathological findings of the placenta. MATERIAL AND METHODS: This is a case series of patients with CAOS managed at our hospital between 2010 and 2020. The clinical data of the patients, including MRI findings and placental pathology, were reviewed retrospectively. RESULTS: A total of 18 patients were eligible. Preterm birth occurred in 17 (94%) cases; the median gestational age at delivery was 25. Three neonates (17%) died within two years, and 10 neonates (56%) developed chronic lung disease. MRI was performed in 13 cases and clearly showed intrauterine hematoma and hemorrhagic amniotic fluid. Pathologically, in all cases, retroplacental hematoma was not detected, and fetal membranes were extremely fragile and ragged. Shedding and necrosis of the amniotic epithelium was a characteristic finding, which was confirmed in 17 cases (94%). Diffuse chorionic hemosiderosis (DCH) was detected in all cases. CONCLUSIONS: The fundamental cause of CAOS is repeated intrauterine hemorrhage and subsequent subchorionic hematoma, which induces hemorrhagic amniotic fluid and DCH. Consequently, these factors result in the necrosis and weakening of the amnion. Therefore, the true pathology of CAOS is believed to be premature rupture of membranes rather than chronic abruption.

Histological distribution pattern of hemosiderin deposition on the chorionic plate and fetal membrane of diffuse chorioamniotic hemosiderosis related to chronic abruption oligohydramnios sequence.

INTRODUCTION: Chronic abruption oligohydramnios sequence (CAOS) is histologically characterized by diffuse chorioamniotic hemosiderosis (DCH). However, the criteria for the histological evaluation of the extent of CAOS-related hemosiderin deposition (HD) of the membranes and the difference in HD between the chorionic plate (CP) and fetal membrane (FM) are not well studied. This case control study compared the degree and distribution pattern of HD on CP and FM to present the histological features of DCH and the criteria for histological evaluation. METHODS: From the medical records of Kyoto University Hospital (2010-2019), we selected 20 CAOS cases that were clinically diagnosed by Elliot's criteria. Twenty non-CAOS cases matched to the CAOS group by gestational age were selected as controls. We compared the clinical data and pathological features in the two groups. We performed iron staining in all the cases and analyzed HD in CP and FM according to the histological score (H-Score: 0-12), which was determined as the density (0-3) multiplied by the extent of staining (0-4). RESULTS: HD was found in 100% (20/20) of CAOS and 15% (3/20) of control cases. In both the FM and CP, CAOS cases showed a significantly higher HS than control cases (CAOS, HS = 4-12; Control, HS = 0-1, p < 0.0001). Three CAOS patients presented HD alone in the CP. The HS of the CP was significantly higher than that of the FM (p = 0.0003). DISCUSSION: CAOS presented DCH with HS ≥ 4. This study showed that the CP might be more suitable for evaluating DCH than the FM.

Primary hepatic lymphoma as other iatrogenic immunodeficiency-related lymphoproliferative disorders: a case report and review of the literature.

We report a case of 68-year-old man with stable polymyositis complicated with primary hepatic lymphoma (PHL) as other iatrogenic immunodeficiency-related lymphoproliferative disorders (OIIA-LPD). Multiple liver masses were diagnosed as diffuse large B-cell lymphoma (DLBCL) by biopsy. The LPD was associated with Epstein-Barr virus (EBV) reactivation, because EBV-DNA was detected in peripheral blood, and EBV antigen was detected in the tumour. He presented with high fever, cytopenia and hyperferritinemia, suggesting hemophagocytosis. Only discontinuation of methotrexate and tacrolimus resulted in a dramatic regression of the liver masses and improvement of fever and cytopenia. We review six cases of OIIA-LPD localised in the liver. All cases were DLBCL; 4/6 cases (67%) were positive for EBV staining, and 2/6 cases (33%) were improved after the discontinuation of immunosuppressants. Screening for EBV in blood and liver tumour is important, when a patient in immunosuppressive status presented with liver masses.