A giant metaplastic breast carcinoma with osseous differentiation: A rare case report and review of the literature.

INTRODUCTION: Metaplastic breast carcinoma (MBC) is a rare form of breast cancer, comprising less than 1 % of all breast malignancies. Osseous differentiation is an extremely rare subtype of MBC, accounting for only 0.003-0.12 % of all breast cancer cases. CASE PRESENTATION: We report a case of advanced-stage metaplastic breast carcinoma with osseous differentiation. The patient received neoadjuvant chemotherapy, but then the tumor progressed to metastasis. Despite palliative surgery, and chemotherapy, the disease did not respond; the patient died shortly later. CLINICAL DISCUSSION: Metaplastic breast carcinoma with osseous differentiation often rapidly progressive, resistant to chemotherapy, and associated with a poor prognosis. Some studies in the literature suggest that MBC tends to spread through the blood rather than lymphatic spread and therefore leads to lung and bone metastases. CONCLUSION: These findings suggest that the role of neoadjuvant chemotherapy in this histopathological group is limited and its use should be carefully considered.

Mental Health of Medical Students After Combating the COVID-19 Epidemic: A Cross-sectional Study in Vietnam.

OBJECTIVES: This study was conducted to investigate the prevalence of mental health (MH) symptoms and associated factors among medical students who were engaged in combating the coronavirus disease 2019 (COVID-19) epidemic in 4 provinces/cities of Vietnam. METHODS: A cross-sectional study with 580 participants was conducted at a medical university in Northern Vietnam. MH was assessed using the 21-item Depression, Anxiety, and Stress Scale, which was previously standardized in Vietnam. Data were collected through a structured self-administered questionnaire. Multivariate logistic regression was employed to examine the association between MH symptoms and relevant factors. RESULTS: Out of a total of 2703 medical students, 21.5% responded to the questionnaire. Among the 580 respondents, the prevalence rates of depression, anxiety, and stress were 43.3%, 44.0%, and 24.7%, respectively. Factors significantly associated with self-reported depression included being female and having a COVID-19 infection. Similarly, being female and having a COVID-19 infection were significantly associated with self-reported anxiety. Factors associated with self-reported stress included being female, having a personal or family history of MH symptoms, working more than 8 hr/day, and having a COVID-19 infection. CONCLUSIONS: COVID-19 has adversely impacted the MH of medical students. Our findings are valuable in their potential to motivate universities, MH professionals, and authorities to offer mental healthcare services to this group. Furthermore, there is a pressing need for training courses designed to equip future healthcare workers with the skills to manage crises effectively.

Recurrent early-stage squamous cell carcinoma cervical cancer presenting with isolated ovary metastasis: a rare case report.

Introduction: Ovarian metastatic squamous carcinoma of the cervix is rare, accounting for about 0.4%. This study reports a single case of metastatic recurrent cervical cancer in the ovary. Case presentation: A 46-year-old patient with a history of cervical cancer T1b2N0M0 underwent a radical hysterectomy, bilateral pelvic lymph node dissection, and ovarian preservation. One year later, the patient was admitted to the hospital because of abdominal pain in the left iliac fossa; the abdominal computed tomography image showed a left ovarian tumour. The patient underwent laparoscopic left oophorectomy. Postoperative histopathology confirmed ovarian squamous cell carcinoma. From this case, we would like to review the literature on epidemiology, diagnosis, treatment, and prognosis. Clinical discussion: Ovarian preservation during surgery in patients with cervical cancer offers many benefits, but careful patient selection is required. However, it should be selected carefully and closely monitored. Conclusions: Clinicians should be aware of this situation of ovarian metastasis in patients with early cervical cancer undergoing ovarian-conserving surgery.

Ovary metastasis from lung cancer mimicking primary ovarian cancer: A rare case report.

Introduction: Ovarian metastasis from lung cancer is very rare, which might lead to a misdiagnosis as primary ovarian cancer. Case presentation: We report a 49-year-old woman presenting to our hospital because of a painful mass in the lower abdomen, with no respiratory symptoms. Her initial diagnosis was stage IVB ovarian cancer with pulmonary metastasis. Therefore, the patient underwent neo-adjuvant Paclitaxel - Carbolatin chemotherapy followed by interval debulking surgery. However, postoperative histopathology and immunohistochemistry findings confirmed the diagnosis of primary lung cancer with ovarian metastases. EGFR exon 19 deletion mutation was found by tumor analysis. Therefore, she was then treated with erlotinib and the disease achieved the partial response and remained stable for 7 months. Conclusion: Diagnosis of lung cancer in the context of ovarian and peritoneal metastases can be difficult. In this circumstance, thorough systemic assessment and immunohistochemistry are essential to confirm the primary.

Rectal metastasis originating from breast cancer: A rare case report.

Introduction: Gastrointestinal tract involvement in breast cancer is rarely encountered clinically. Data about this condition is limited and mostly from case reports. Case presentation: We report a case of rectal metastasis originating from breast cancer, which presents after a long-term latency of initial diagnosis. The patient had a history of diagnosis and treatment of stage II triple-negative breast cancer with mastectomy and adjuvant chemotherapy and radiotherapy. She showed no signs of recurrence up to eleven years, then presented with hematochezia and mild constipation. A rectal lesion was found on colonoscopy, which raise the initial suspicion of primary rectal cancer, but surprisingly, immunohistochemistry staining of the rectal specimen confirmed the origin of breast cancer. Clinical discussion: Breast cancer with rectal metastasis is very rare. Immunohistochemistry combined with medical history is essential for definitive diagnosis in this situation. Mammaglobin and GCDFP-15, CDX2, CK20, and CK7 help differentiate the origin from the breast or the rectum. Conclusion: Though breast cancer metastasizing to the rectum is a rare event, physicians should be aware of this differential diagnosis, even in patients with a remote history of breast cancer.

Recurrent ovarian cancer presenting with isolated axillary lymph node metastasis: A rare case report.

Introduction: Ovarian cancer with metastatic axillary lymph node is a very rare entity. This study aims to report a case of recurrent ovarian cancer presenting with isolated axillary lymph node metastasis. Case presentation: We report a case of a 58-year-old patient with recurrent ovarian cancer in the axillary node and a suspected lesion in the ipsilateral breast. One year before recurrence, the patient was diagnosed with FIGO stage IIIC ovarian cancer and was treated with primary debulking and paclitaxel-carboplatin adjuvant chemotherapy. Biopsies of the breast lesion, right and left axillary lymph node yielded a fibroadenoma in the breast and a metastatic carcinoma in the axillary node. Immunohistochemistry stains of the left axillary node biopsy specimen was positive for CK7, P53 and PAX-8 markers, and negative for CK20 and GCDFP-15 markers. Immunohistochemistry results combined with a history of ovarian cancer helped confirm the ovarian origin of axillary lymph node metastasis. Clinical discussion: Recurrent ovarian cancer presenting with isolated axillary lymph node metastasis is rare. Immunohistochemistry combined with medical history is essential for definitive diagnosis in this situation. PAX-8 and GCDFP-15 help to differentiate the origin from the breast or the ovary. Conclusion: Oncologists and pathologists should recognize this rare clinical scenario for early diagnosis and treatment. Detailed medical history, imaging, and immunohistochemical studies on biopsy specimen should help reach accurate diagnosis.

Clinical characteristics and factors relating to poor outcome in patients with aneurysmal subarachnoid hemorrhage in Vietnam: A multicenter prospective cohort study.

BACKGROUND: The prevalence of risk factors for poor outcomes from aneurysmal subarachnoid hemorrhage (SAH) varies widely and has not been fully elucidated to date in Vietnam. Understanding the risk and prognosis of aneurysmal SAH is important to reduce poor outcomes in Vietnam. The aim of this study, therefore, was to investigate the rate of poor outcome at 90 days of ictus and associated factors from aneurysmal SAH in the country. METHODS: We performed a multicenter prospective cohort study of patients (≥18 years) presenting with aneurysmal SAH to three central hospitals in Hanoi, Vietnam, from August 2019 to August 2020. We collected data on the characteristics, management, and outcomes of patients with aneurysmal SAH and compared these data between good (defined as modified Rankin Scale (mRS) of 0 to 3) and poor (mRS, 4-6) outcomes at 90 days of ictus. We assessed factors associated with poor outcomes using logistic regression analysis. RESULTS: Of 168 patients with aneurysmal SAH, 77/168 (45.8%) were men, and the median age was 57 years (IQR: 48-67). Up to 57/168 (33.9%) of these patients had poor outcomes at 90 days of ictus. Most patients underwent sudden-onset and severe headache (87.5%; 147/168) and were transferred from local to participating central hospitals (80.4%, 135/168), over half (57.1%, 92/161) of whom arrived in central hospitals after 24 hours of ictus, and the initial median World Federation of Neurological Surgeons (WFNS) grading score was 2 (IQR: 1-4). Nearly half of the patients (47.0%; 79/168) were treated with endovascular coiling, 37.5% (63/168) were treated with surgical clipping, the remaining patients (15.5%; 26/168) did not receive aneurysm repair, and late rebleeding and delayed cerebral ischemia (DCI) occurred in 6.1% (10/164) and 10.4% (17/163) of patients, respectively. An initial WFNS grade of IV (odds ratio, OR: 15.285; 95% confidence interval, CI: 3.096-75.466) and a grade of V (OR: 162.965; 95% CI: 9.975-2662.318) were independently associated with poor outcomes. Additionally, both endovascular coiling (OR: 0.033; 95% CI: 0.005-0.235) and surgical clipping (OR: 0.046; 95% CI: 0.006-0.370) were inversely and independently associated with poor outcome. Late rebleeding (OR: 97.624; 95% CI: 5.653-1686.010) and DCI (OR: 15.209; 95% CI: 2.321-99.673) were also independently associated with poor outcome. CONCLUSIONS: Improvements are needed in the management of aneurysmal SAH in Vietnam, such as increasing the number of aneurysm repairs, performing earlier aneurysm treatment by surgical clipping or endovascular coiling, and improving both aneurysm repairs and neurocritical care.

A Pixel Design of a Branching Ultra-Highspeed Image Sensor.

A burst image sensor named Hanabi, meaning fireworks in Japanese, includes a branching CCD and multiple CMOS readout circuits. The sensor is backside-illuminated with a light/charge guide pipe to minimize the temporal resolution by suppressing the horizontal motion of signal carriers. On the front side, the pixel has a guide gate at the center, branching to six first-branching gates, each bifurcating to second-branching gates, and finally connected to 12 (=6×2) floating diffusions. The signals are either read out after an image capture operation to replay 12 to 48 consecutive images, or continuously transferred to a memory chip stacked on the front side of the sensor chip and converted to digital signals. A CCD burst image sensor enables a noiseless signal transfer from a photodiode to the in-situ storage even at very high frame rates. However, the pixel count conflicts with the frame count due to the large pixel size for the relatively large in-pixel CCD memory elements. A CMOS burst image sensor can use small trench-type capacitors for memory elements, instead of CCD channels. However, the transfer noise from a floating diffusion to the memory element increases in proportion to the square root of the frame rate. The Hanabi chip overcomes the compromise between these pros and cons.

Toward the Super Temporal Resolution Image Sensor with a Germanium Photodiode for Visible Light.

The theoretical temporal resolution limit tT of a silicon photodiode (Si PD) is 11.1 ps. We call "super temporal resolution" the temporal resolution that is shorter than that limit. To achieve this resolution, Germanium is selected as a candidate material for the photodiode (Ge PD) for visible light since the absorption coefficient of Ge for the wavelength is several tens of times higher than that of Si, allowing a very thin PD. On the other hand, the saturation drift velocity of electrons in Ge is about 2/3 of that in Si. The ratio suggests an ultra-short propagation time of electrons in the Ge PD. However, the diffusion coefficient of electrons in Ge is four times higher than that of Si. Therefore, Monte Carlo simulations were applied to analyze the temporal resolution of the Ge PD. The estimated theoretical temporal resolution limit is 0.26 ps, while the practical limit is 1.41 ps. To achieve a super temporal resolution better than 11.1 ps, the driver circuit must operate at least 100 GHz. It is thus proposed to develop, at first, a short-wavelength infrared (SWIR) ultra-high-speed image sensor with a thicker and wider Ge PD, and then gradually decrease the size along with the progress of the driver circuits.

Light-In-Flight Imaging by a Silicon Image Sensor: Toward the Theoretical Highest Frame Rate.

Light in flight was captured by a single shot of a newly developed backside-illuminated multi-collection-gate image sensor at a frame interval of 10 ns without high-speed gating devices such as a streak camera or post data processes. This paper reports the achievement and further evolution of the image sensor toward the theoretical temporal resolution limit of 11.1 ps derived by the authors. The theoretical analysis revealed the conditions to minimize the temporal resolution. Simulations show that the image sensor designed following the specified conditions and fabricated by existing technology will achieve a frame interval of 50 ps. The sensor, 200 times faster than our latest sensor will innovate advanced analytical apparatuses using time-of-flight or lifetime measurements, such as imaging TOF-MS, FLIM, pulse neutron tomography, PET, LIDAR, and more, beyond these known applications.

An Image Signal Accumulation Multi-Collection-Gate Image Sensor Operating at 25 Mfps with 32 × 32 Pixels and 1220 In-Pixel Frame Memory.

The paper presents an ultra-high-speed image sensor for motion pictures of reproducible events emitting very weak light. The sensor is backside-illuminated. Each pixel is equipped with multiple collection gates (MCG) at the center of the front side. Each collection gate is connected to an in-pixel large memory unit, which can accumulate image signals captured by repetitive imaging. The combination of the backside illumination, image signal accumulation, and slow readout from the in-pixel signal storage after an image capturing operation offers a very high sensitivity. Pipeline signal transfer from the the multiple collection gates (MCG) to the in-pixel memory units enables the sensor to achieve a large frame count and a very high frame rate at the same time. A test sensor was fabricated with a pixel count of 32 × 32 pixels. Each pixel is equipped with four collection gates, each connected to a memory unit with 305 elements; thus, with a total frame count of 1220 (305 × 4) frames. The test camera achieved 25 Mfps, while the sensor was designed to operate at 50 Mfps.

Toward the Ultimate-High-Speed Image Sensor: From 10 ns to 50 ps.

The paper summarizes the evolution of the Backside-Illuminated Multi-Collection-Gate (BSI MCG) image sensors from the proposed fundamental structure to the development of a practical ultimate-high-speed silicon image sensor. A test chip of the BSI MCG image sensor achieves the temporal resolution of 10 ns. The authors have derived the expression of the temporal resolution limit of photoelectron conversion layers. For silicon image sensors, the limit is 11.1 ps. By considering the theoretical derivation, a high-speed image sensor designed can achieve the frame rate close to the theoretical limit. However, some of the conditions conflict with performance indices other than the frame rate, such as sensitivity and crosstalk. After adjusting these trade-offs, a simple pixel model of the image sensor is designed and evaluated by simulations. The results reveal that the sensor can achieve a temporal resolution of 50 ps with the existing technology.

The Theoretical Highest Frame Rate of Silicon Image Sensors.

The frame rate of the digital high-speed video camera was 2000 frames per second (fps) in 1989, and has been exponentially increasing. A simulation study showed that a silicon image sensor made with a 130 nm process technology can achieve about 1010 fps. The frame rate seems to approach the upper bound. Rayleigh proposed an expression on the theoretical spatial resolution limit when the resolution of lenses approached the limit. In this paper, the temporal resolution limit of silicon image sensors was theoretically analyzed. It is revealed that the limit is mainly governed by mixing of charges with different travel times caused by the distribution of penetration depth of light. The derived expression of the limit is extremely simple, yet accurate. For example, the limit for green light of 550 nm incident to silicon image sensors at 300 K is 11.1 picoseconds. Therefore, the theoretical highest frame rate is 90.1 Gfps (about 1011 fps).