Actinomycosis of the Gallbladder: A Case Report

Introduction: Actinomycosis of the gallbladder is extremely rare and may mimic a malignancy leading to delayed diagnosis and/or inappropriate treatment.Presentation of case: Here we report the case of an 82-year-old man who presented with right upper abdominal discomfort for one month. Radiographically, an ill-defined mass was found in the gallbladder fossa that invaded the adjacent abdominal wall and liver bed. In addition, a stone was found in the gallbladder lumen. The imaging features suggested a gallbladder carcinoma. An initial CT-guided needle biopsy showed an inflammatory process. The subsequent open cholecystectomy revealed a contracted, thick-walled gallbladder surrounded by a soft tissue mass near the fundus. Histologically, the gallbladder revealed acute and chronic cholecystitis and microabscesses containing sulfur granules in the soft tissue mass, which showed Gram-positive filamentous bacilli. Under the diagnosis of gallbladder actinomycosis, the patient received post-operative antibiotics for 7 weeks and was well 5 months after diagnosis.Conclusion: Our case demonstrated that a gallbladder actinomycosis should be considered in the differential diagnosis in patients with cholelithiasis and cholecystitis presenting an invasive mass in the gallbladder fossa

Perivascular Interstitial Cells of Cajal in Human ColonSummary

Background & Aims: Interstitial cells of Cajal (ICC) closely associate with nerves and smooth muscles to modulate gut motility. In the ICC microenvironment, although the circulating hormones/factors have been shown to influence ICC activities, the association between ICC and microvessels in the gut wall has not been described. We applied three-dimensional (3D) vascular histology with c-kit staining to identify the perivascular ICC and characterize their morphologic and population features in the human colon wall. Methods: Full-thickness colons were obtained from colectomies performed for colorectal cancer. We targeted the colon wall away from the tumor site. Confocal microscopy with optical clearing (use of immersion solution to reduce scattering in optical imaging) was performed to simultaneously reveal the ICC and vascular networks in space. 3D image rendering and projection were digitally conducted to illustrate the ICCâvessel contact patterns. Results: Perivascular ICC were identified in the submucosal border, myenteric plexus, and circular and longitudinal muscles via high-definition 3D microscopy. Through in-depth image projection, we specified two contact patternsâthe intimate cell body-to-vessel contact (type I, 18% of ICC in circular muscle) and the long-distance process-to-vessel contact (type II, 16%)âto classify perivascular ICC. Particularly, type I perivascular ICC were detected with elevated c-kit staining levels and were routinely found in clusters, making them readily distinguishable from other ICC in the network. Conclusions: We propose a new subclass of ICC that closely associates with microvessels in the human colon. Our finding suggests a functional relationship between these mural ICC and microvessels based on the morphologic proximity. Keywords: 3D Histology, c-kit, ICC, Mural Cell

-D Visualization and Quantitation of Microvessels in Transparent Human Colorectal Carcinoma

<div><p>Microscopic analysis of tumor vasculature plays an important role in understanding the progression and malignancy of colorectal carcinoma. However, due to the geometry of blood vessels and their connections, standard microtome-based histology is limited in providing the spatial information of the vascular network with a 3-dimensional (3-D) continuum. To facilitate 3-D tissue analysis, we prepared transparent human colorectal biopsies by optical clearing for in-depth confocal microscopy with CD34 immunohistochemistry. Full-depth colons were obtained from colectomies performed for colorectal carcinoma. Specimens were prepared away from (control) and at the tumor site. Taking advantage of the transparent specimens, we acquired anatomic information up to 200 μm in depth for qualitative and quantitative analyses of the vasculature. Examples are given to illustrate: (1) the association between the tumor microstructure and vasculature in space, including the perivascular cuffs of tumor outgrowth, and (2) the difference between the 2-D and 3-D quantitation of microvessels. We also demonstrate that the optically cleared mucosa can be retrieved after 3-D microscopy to perform the standard microtome-based histology (H&E staining and immunohistochemistry) for systematic integration of the two tissue imaging methods. Overall, we established a new tumor histological approach to integrate 3-D imaging, illustration, and quantitation of human colonic microvessels in normal and cancerous specimens. This approach has significant promise to work with the standard histology to better characterize the tumor microenvironment in colorectal carcinoma.</p> </div