Testicular Mixed Germ Cell Tumor Presenting with Upper Gastrointestinal Bleeding: A Case Report.

Testicular mixed germ cell tumors (TMGCTs) are aggressive neoplasms that often have metastases at the time of diagnosis, primarily in the lungs, bones, and brain. Gastrointestinal metastases are rare, occurring in less than 5% of cases, while duodenal involvement is extremely rare, with only few reported cases. Furthermore, gastrointestinal bleeding is an atypical initial presentation of metastatic TMGCTs. Herein, we present a very rare case of upper gastrointestinal bleeding caused by a duodenal metastasis of a TMGCT in a 24-year-old man. The patient was admitted to our hospital due to abdominal pain and melena with a hemoglobin level of 52 g/L. He had no history of testicular swelling, or any other symptoms or signs of a testicular tumor. Upper gastrointestinal endoscopy revealed a duodenal tumor mass with irregular bleeding, and abdominal ultrasound and computed tomography showed a duodenal mass that infiltrate retroperitoneum. Emergency surgery was performed, and the histopathological findings of the resected specimen were consistent with TMGCT metastasis. Subsequently, a testicular tumor was confirmed and surgically removed; however, multiple metastatic deposits were observed in the lungs. Due to the patient's poor general condition, chemotherapy was not performed. The patient died 3 months after the initial diagnosis. This case suggests that, although duodenal metastatic TMGCTs are rare, they should be considered in the differential diagnosis of gastrointestinal bleeding in young male patients.

Decoupling channel count from field of view and spatial resolution in single-sensor imaging systems for fluorescence image-guided surgery.

Significance: Near-infrared fluorescence image-guided surgery is often thought of as a spectral imaging problem where the channel count is the critical parameter, but it should also be thought of as a multiscale imaging problem where the field of view and spatial resolution are similarly important. Aim: Conventional imaging systems based on division-of-focal-plane architectures suffer from a strict relationship between the channel count on one hand and the field of view and spatial resolution on the other, but bioinspired imaging systems that combine stacked photodiode image sensors and long-pass/short-pass filter arrays offer a weaker tradeoff. Approach: In this paper, we explore how the relevant changes to the image sensor and associated image processing routines affect image fidelity during image-guided surgeries for tumor removal in an animal model of breast cancer and nodal mapping in women with breast cancer. Results: We demonstrate that a transition from a conventional imaging system to a bioinspired one, along with optimization of the image processing routines, yields improvements in multiple measures of spectral and textural rendition relevant to surgical decision-making. Conclusions: These results call for a critical examination of the devices and algorithms that underpin image-guided surgery to ensure that surgeons receive high-quality guidance and patients receive high-quality outcomes as these technologies enter clinical practice.

Hexachromatic bioinspired camera for image-guided cancer surgery.

Cancer affects one in three people worldwide. Surgery remains the primary curative option for localized cancers, but good prognoses require complete removal of primary tumors and timely recognition of metastases. To expand surgical capabilities and enhance patient outcomes, we developed a six-channel color/near-infrared image sensor inspired by the mantis shrimp visual system that enabled near-infrared fluorescence image guidance during surgery. The mantis shrimp's unique eye, which maximizes the number of photons contributing to and the amount of information contained in each glimpse of its surroundings, is recapitulated in our single-chip imaging system that integrates arrays of vertically stacked silicon photodetectors and pixelated spectral filters. To provide information about tumor location unavailable from a single instrument, we tuned three color channels to permit an intuitive perspective of the surgical procedure and three near-infrared channels to permit multifunctional imaging of optical probes highlighting cancerous tissue. In nude athymic mice bearing human prostate tumors, our image sensor enabled simultaneous detection of two tumor-targeted fluorophores, distinguishing diseased from healthy tissue in an estimated 92% of cases. It also permitted extraction of near-infrared structured illumination enabling the mapping of the three-dimensional topography of tumors and surgical sites to within 1.2-mm error. In the operating room, during surgical resection in 18 patients with breast cancer, our image sensor further enabled sentinel lymph node mapping using clinically approved near-infrared fluorophores. The flexibility and performance afforded by this simple and compact architecture highlights the benefits of biologically inspired sensors in image-guided surgery.