Characterization of Morphologic and Cytochemical Staining Properties of Exogenous Materials Mimicking Fungal Organisms Encountered in Skin Biopsies.

BACKGROUND: Exogenous materials may be encountered in skin biopsies as contamination. Contamination may occur during the biopsy procedure in the clinic or during tissue processing in the laboratory. Although the experienced pathologist may often instinctively ignore clear examples of contamination, such tissue may be a source of confusion for young pathologists and those in training. Foreign materials can typically be recognized as exogenous by morphology, polarizability, and the presence or absence of a tissue reaction, but we have rarely encountered situations in which exogenous materials could be misinterpreted as organisms, either by their morphologic appearance or staining properties. METHODS: Exogenous materials used during skin biopsy and grossing were embedded in a nonhuman tissue scaffold and prepared into histologic slides. Hematoxylin and eosin (H&E), periodic acid-Schiff with diastase, and Grocott methenamine silver stains were performed, and each material was evaluated under polarized microscopy. RESULTS: Exogenous materials were divided into the following 3 categories with shared morphologic appearances and staining properties: suture materials, plant-based materials, and synthetic materials. CONCLUSION: We present a comprehensive characterization of the morphologic and cytochemical staining properties of multiple exogenous materials that may contaminate a skin biopsy. This characterization will aid the pathologist by providing a mechanism to identify potential contaminants in skin biopsies.

Randomized controlled trial comparing the Franseen needle with the Fork-tip needle for EUS-guided fine-needle biopsy.

BACKGROUND AND AIMS: EUS-guided FNA primarily provides cytologic samples. EUS-guided fine-needle biopsy (FNB) with needles that provide histologic specimens may enhance diagnostic yield and facilitate accessory tissue staining. Several different needle designs are currently available and design superiority is unknown. We designed a randomized controlled trial to compare 2 commonly used EUS-FNB needles in their ability to provide histologic tissue samples (primary endpoint) and to reach an accurate diagnosis (secondary endpoint). METHODS: A total of 150 lesions from 134 patients (November 2018 to June 2019) were randomized 1:1 between biopsy with a Franseen needle and a Fork-tip needle. The groups were compared regarding the quality of the tissue samples and diagnostic accuracy. RESULTS: Of 150 lesions, 75 were pancreatic and 75 were other solid lesions in and around the GI tract. There was no statistically significant difference between the Franseen needle and the Fork-tip needle in the yield of adequate histologic samples, 71 of 75 (94.7%) versus 72 of 75 (96%), (P = 1.00), an absolute difference of -1.3% (95% confidence interval [CI], -8.1% to 5.4%). The 2 groups were similar in the diagnostic accuracy of histologic analysis, 64 of 75 (85.3%) versus 68 of 75 (90.7%) (P = .45), absolute difference -5.4% (95% CI, -15.7% to 5%); and in the diagnostic accuracy of combined cytologic and histologic analysis, 65 of 75 (86.7%) versus 69 of 75 (92%) (P = .43), absolute difference -5.3% (95% CI, -15.2% to 4.5%). CONCLUSIONS: There was no significant difference in the performance of the Franseen needle versus the Fork-tip needle. Both needles achieved a high yield of histologic tissue samples and high diagnostic accuracy. (Clinical trial registration number: NCT03672032.).

Molecular changes in bone marrow, tumor and serum after conductive ablation of murine 4T1 breast carcinoma.

Thermal ablation of solid tumors using conductive interstitial thermal therapy (CITT) produces coagulative necrosis in the center of ablation. Local changes in homeostasis for surviving tumor and systemic changes in circulation and distant organs must be understood and monitored in order to prevent tumor re-growth and metastasis. The purpose of this study was to use a mouse carcinoma model to evaluate molecular changes in the bone marrow and surviving tumor after CITT treatment by quantification of transcripts associated with cancer progression and hyperthermia, serum cytokines, stress proteins and the marrow/tumor cross-talk regulator stromal-derived factor 1. Analysis of 27 genes and 22 proteins with quantitative PCR, ELISA, immunoblotting and multiplex antibody assays revealed that the gene and protein expression in tissue and serum was significantly different between ablated and control mice. The transcripts of four genes (Cxcl12, Sele, Fgf2, Lifr) were significantly higher in the bone marrow of treated mice. Tumors surviving ablation showed significantly lower levels of the Lifr and Sele transcripts. Similarly, the majority of transcripts measured in tumors decreased with treatment. Surviving tumors also contained lower levels of SDF-1α and HIF-1α proteins whereas HSP27 and HSP70 were higher. Of 16 serum chemokines, IFNγ and GM-CSF levels were lower with treatment. These results indicate that CITT ablation causes molecular changes which may slow cancer cell proliferation. However, inhibition of HSP27 may be necessary to control aggressiveness of surviving cancer stem cells. The changes in bone marrow are suggestive of possible increased recruitment of circulatory cancer cells. Therefore, the possibility of heightened bone metastasis after thermal ablation needs to be further investigated and inhibition strategies developed, if warranted.