Characterization of acrylic polyamide plastic embolization particles in vitro and in human tissue sections by light microscopy, infrared microspectroscopy and scanning electron microscopy with energy dispersive X-ray analysis

Gastrointestinal Tract Injury by Yttrium-90 Appears Largely Restricted to Resin Microspheres But Can Occur Years After Embolization

Radioembolization therapy utilizes yttrium-90 (Y90) impregnated resin (SIR-Spheres) or glass (TheraSpheres) microspheres to selectively target hepatic lesions via transarterial radioembolization. Occasional cases of gastrointestinal tract injury, secondary to nontargeted delivery of microspheres, have been reported, but large descriptive pathology series are lacking. We identified 20 cases of histologically confirmed mucosal injury associated with Y90 from 17 patients and assessed the corresponding clinical and pathologic sequelae. The mucosal biopsies were obtained from 1 to 88 months following Y90 therapy (median: 5 mo). Most cases were gastric (17, 85%), while the remaining were duodenal. Endoscopic ulceration was seen in the majority of cases (16, 80%), and mucosal erythema in the remaining 4. Histologically, a majority (19, 95%) of cases showed rounded, dark blue to purple microspheres measuring 4 to 30 µm, consistent with resin microspheres. A single case with glass microspheres demonstrated 26 µm translucent beads. Histologic evidence of ulceration was appreciated in 14 (70%) cases, and the microspheres were clearly intravascular in 6 (30%). A foreign body giant cell reaction to the microspheres was uncommon (3 cases, 15%). We additionally performed a retrospective review of all gastrointestinal tissue obtained postprocedure from 784 sequential patients treated with Y90 microspheres. Three patients (0.4%) demonstrated the presence of resin microspheres upon histologic examination. No cases involving glass-based Y90 were identified (P=0.0078), despite the majority of patients having received glass radioembolization (630, 80%). This increased risk of secondary sphere dissemination is likely related to the increased number of particles required per activity for resin versus glass microspheres. We conclude that Y90 microspheres may be encountered in the gastrointestinal tract years after initial liver-targeted therapy and, when present, are often associated with mucosal ulceration. This finding is less likely to be encountered in patients who received Y90 radioembolization utilizing glass microspheres.

Infrared metrics for fixation-free liver tumor detection

Infrared (IR) spectroscopic imaging of human liver tissue slices has been used to identify and characterize liver tumors. Liver tissue, containing a liver metastasis of breast origin (mucinous carcinoma), was surgically removed from a consenting patient and frozen without formalin fixation or dehydration procedures, so that lipids and water remained in the tissues. A set of IR metrics (ratios of various IR peaks) was determined for tumors in fixation-free liver tissues. K-means cluster analysis was used to tell tumor from nontumor. In this case, there was a large reduction in lipid content upon going from nontumor to tumor tissue, and a well-resolved IR spectrum of nontumor liver lipid was obtained and analyzed. These IR metrics may someday guide work on IR spectroscopic diagnostics on patients in the operating room. This work also suggests utility for these methods beyond the identification of liver tumors, perhaps in the study of liver lipids.

Clinical, epidemiologic, histopathologic and molecular features of an unexplained dermopathy

BACKGROUND

Morgellons is a poorly characterized constellation of symptoms, with the primary manifestations involving the skin. We conducted an investigation of this unexplained dermopathy to characterize the clinical and epidemiologic features and explore potential etiologies.

METHODS

A descriptive study was conducted among persons at least 13 years of age and enrolled in Kaiser Permanente Northern California (KPNC) during 2006-2008. A case was defined as the self-reported emergence of fibers or materials from the skin accompanied by skin lesions and/or disturbing skin sensations. We collected detailed epidemiologic data, performed clinical evaluations and geospatial analyses and analyzed materials collected from participants' skin.

RESULTS

We identified 115 case-patients. The prevalence was 3.65 (95% CI = 2.98, 4.40) cases per 100,000 enrollees. There was no clustering of cases within the 13-county KPNC catchment area (p = .113). Case-patients had a median age of 52 years (range: 17-93) and were primarily female (77%) and Caucasian (77%). Multi-system complaints were common; 70% reported chronic fatigue and 54% rated their overall health as fair or poor with mean Physical Component Scores and Mental Component Scores of 36.63 (SD = 12.9) and 35.45 (SD = 12.89), respectively. Cognitive deficits were detected in 59% of case-patients and 63% had evidence of clinically significant somatic complaints; 50% had drugs detected in hair samples and 78% reported exposure to solvents. Solar elastosis was the most common histopathologic abnormality (51% of biopsies); skin lesions were most consistent with arthropod bites or chronic excoriations. No parasites or mycobacteria were detected. Most materials collected from participants' skin were composed of cellulose, likely of cotton origin.

CONCLUSIONS

This unexplained dermopathy was rare among this population of Northern California residents, but associated with significantly reduced health-related quality of life. No common underlying medical condition or infectious source was identified, similar to more commonly recognized conditions such as delusional infestation.

Uterine artery embolization with trisacryl gelatin microspheres in women treated for leiomyomas: a clinicopathologic analysis of alterations in gynecologic surgical specimens

To characterize the histologic range of alterations due to uterine artery embolization with trisacryl gelatin microspheres in gynecologic specimens containing leiomyomas in detail, we report our clinicopathologic experience with 26 cases (longest postuterine artery embolization interval, 1.9 yr). Microspheres were observed in 85% of cases and could be seen up to 1.9 years after embolization. They were mainly present in leiomyomas and nonneoplastic myometrium but could be found in other nontargeted sites, such as the cervix, endometrium, ovaries, and fallopian tubes; however, infarction (present in 96% of cases) was confined to leiomyomas and did not involve other nonneoplastic tissues. The appearance of the infarcts was correlated with time after embolization, and coagulative necrosis/necrosis of indeterminate type was restricted to the early period after uterine artery embolization (before 10 wk postuterine artery embolization) whereas hyaline necrosis was seen predominantly in the late period (mostly after 10 wk, up to 1.9 yr). Of the 14 hysterectomy specimens with microspheres in extravascular spaces (almost all of which were in close proximity to the arteries), pseudoaneurysms were also focally present in 8 (57%) specimens. Microspheres were usually associated with mild inflammatory reactions, which persisted >1 year after embolization but did not become more severe over time. Morphologic and histochemical features of trisacryl gelatin microspheres were compared with other embolization agents, which can also be encountered in surgical specimens [polyvinyl alcohol (PVA) particles and PVA microspheres]. Trisacryl gelatin microspheres were negative with periodic acid-Schiff and orange-pink with Movat stains whereas PVA was positive with periodic acid-Schiff and black with Movat. Our study, the largest histologic analysis to date, confirms and extends the observations of earlier studies of trisacryl gelatin microspheres. In addition, we conclude that, as expected, the histologic appearance of microsphere-induced infarcts is a function of time, similar to healing of infarcts in nongynecologic sites. Pseudoaneurysms are a likely mechanism for the production of microspheres in extravascular spaces. Inflammation associated with microspheres can persist in gynecologic tissues but does not seem to result in the destruction of nontargeted sites. Finally, trisacryl gelatin microspheres can be distinguished from PVA particles and PVA microspheres based on a combination of morphologic features and histochemical stains.

Deposition of calcium salts in a case of pulmonary zygomycosis: histopathologic and chemical findings

We report a case of pulmonary zygomycosis associated with unusual deposition of calcium salt crystals. The patient was a 75-year-old female who had onset of cough and shortness of breath. She was treated for community-acquired pneumonia but died despite intensive therapy. Postmortem examination revealed diffuse alveolar damage and multifocal necrotizing pneumonia associated with herpes simplex infection and invasive zygomycosis. Birefringent particles were seen associated with fungal elements in the lung parenchyma, within bronchial cartilage, and in blood vessel walls. By infrared spectroscopy, the birefringent particles in the pulmonary parenchyma and within bronchial cartilage had spectral characteristics of calcium oxalate dihydrate and calcium oxalate monohydrate, respectively. The birefringent crystals within vascular walls were identified as calcium carbonate. This case documents the chemical composition and location of 3 different calcium salt crystals in pulmonary zygomycosis. It also shows that among pulmonary fungal infections, calcium oxalate deposition is not restricted to aspergillosis.

Alcian Blue Staining Method to Visualize Bonghan Threads Inside Large Caliber Lymphatic Vessels And X-Ray Microtomography to Reveal Their Microchannels

BACKGROUND

Novel threadlike structures, so-called Bonghan threads, inside large caliber lymphatic vessels were recently observed by using the Janus Green B staining in the case of rabbits, and by using fluorescent magnetic nanoparticles for rats. They are thought to have channels through which some liquid with abundant hyaluronic acid (HA) flows. In the present work, the authors put forward a hypothesis to test that the Bonghan threads can be visualized in vivo by HA-staining dye, Alcian blue, and that the channels may be revealed by using X-ray microtomography.

METHODS AND RESULTS

Alcain blue was injected into a lymph vessel near the caudal vena cava of a rat to make the Bonghan threads visible. Specimens were stained with YoYo-1 and Masson's trichrome. They were also examined by confocal microscopy and X-ray microtomography. A Bonghan thread was well stained by Alcian blue and was about 50 microm thick and 10-20 times thinner than the surrounding lymphatic vessel. It had a broken line shape, with a distribution of rod-shaped nuclei, which is the characteristic of Bonghan threads in general. Whereas lymphatic vessels are surrounded by a collagenous matrix, Bonghan threads do not contain any collagenous component. X-ray microtomography revealed continuous microchannels inside the Bonghan threads.

CONCLUSIONS

Bonghan threads contain HA abundantly, harbor continuous microchannels, and have characteristic distribution of the rod-shape nuclei. Thus, they are novel anatomical structures with liquid-carrying microchannels.