Frozen section diagnosis of gastrointestinal poorly cohesive and signet-ring cell adenocarcinoma: useful morphologic features to avoid misdiagnosis

The Visible Stomach: Elusive Diffuse-Type Adenocarcinoma Presents With Gastric Outlet Obstruction

The diagnosis of diffuse-type gastric cancers may be challenging due to their submucosal infiltration. A male in his early 60s was diagnosed with signet-ring cell adenocarcinoma of the diffuse type based on a biopsy from a perforated gastric ulcer. Postoperative workup was negative, including repeated esophagogastroduodenoscopy, gastric biopsies, tumor markers, computed tomography (CT), and positron emission tomography (PET). Six months after the operation, the patient presented to our center with abdominal discomfort and nausea. The clinical examination showed an enlarged visible stomach due to gastric outlet obstruction. The patient underwent total gastrectomy after confirmation of malignancy using an intraoperative frozen section. However, the tumor was already advanced locally and regionally. Confirmed malignancy in biopsies from perforated gastric ulcers should be never considered false positivity. To avoid missing a diffuse gastric cancer, endoscopic biopsies should be obtained using advanced techniques such as submucosal dissection under endosonographic guidance.

Rapid brain structure and tumour margin detection on whole frozen tissue sections by fast multiphotometric mid-infrared scanning

Frozen section analysis is a frequently used method for examination of tissue samples, especially for tumour detection. In the majority of cases, the aim is to identify characteristic tissue morphologies or tumour margins. Depending on the type of tissue, a high number of misdiagnoses are associated with this process. In this work, a fast spectroscopic measurement device and workflow was developed that significantly improves the speed of whole frozen tissue section analyses and provides sufficient information to visualize tissue structures and tumour margins, dependent on their lipid and protein molecular vibrations. That optical and non-destructive method is based on selected wavenumbers in the mid-infrared (MIR) range. We present a measuring system that substantially outperforms a commercially available Fourier Transform Infrared (FT-IR) Imaging system, since it enables acquisition of reduced spectral information at a scan field of 1 cm² in 3 s, with a spatial resolution of 20 µm. This allows fast visualization of segmented structure areas with little computational effort. For the first time, this multiphotometric MIR system is applied to biomedical tissue sections. We are referencing our novel MIR scanner on cryopreserved murine sagittal and coronal brain sections, especially focusing on the hippocampus, and show its usability for rapid identification of primary hepatocellular carcinoma (HCC) in mouse liver.