Dibson D. Gondim

Endoscopic ultrasound-guided liver biopsy: a multicenter experience.

Background and aims: Endoscopic ultrasound-guided (EUS) liver biopsy (LB) is proposed as a newer method that offers several advantages over existing techniques for sampling liver tissue. This study evaluated the diagnostic yield of EUS-LB as the primary outcome measure. In addition, the safety of the technique in a large patient cohort was assessed. Patients and methods: Patients undergoing EUS for evaluation of elevated liver enzymes or hepatic disease were included in this prospective, non-randomized, multicenter study. EUS-LB was performed with EUS-fine needle aspiration (FNA; 19-gauge needle). Tissue was formalin-fixed and stained with hematoxylin and eosin, and trichrome. Using a microscope micrometer, specimen length was measured and the number of complete portal triads (CPTs) were counted. The main outcome measure was to assess the diagnostic yield of EUS-LB, and to monitor for any procedure-related complications. Results: Patients (110; median age, 53 years; 62 women) underwent EUS-LB at eight centers. The indication was abnormal liver enzymes in 96 patients. LB specimens sufficient for pathological diagnosis were obtained in 108 of 110 patients (98 %). The overall tissue yield from 110 patients was a median aggregate length of 38 mm (range, 0 – 203), with median of 14 CPTs (range, 0 – 68). There was no statistical difference in the yield between bilobar, left lobe only, or right lobe only biopsies. There was one complication (0.9 %) where self-limited bleeding occurred in a coagulopathic and thrombocytopenic patient. This complication was managed conservatively. Conclusions: EUS-guided LB was a safe technique that yields tissue adequate for diagnosis among 98 % of patients evaluated.

Renal Cell Carcinoma With Chromosome 6p Amplification Including the TFEB Gene: A Novel Mechanism of Tumor Pathogenesis?

Amplification of chromosome 6p has been implicated in aggressive behavior in several cancers, but has not been characterized in renal cell carcinoma (RCC). We identified 9 renal tumors with amplification of chromosome 6p including the TFEB gene, 3 by fluorescence in situ hybridization, and 6 from the Cancer Genome Atlas (TCGA) databases. Patients’ ages were 28 to 78 years (median, 61 y). Most tumors were high stage (7/9 pT3a, 2/9 pN1). Using immunohistochemistry, 2/4 were positive for melanocytic markers and cathepsin K. Novel TFEB fusions were reported by TCGA in 2; however, due to a small composition of fusion transcripts compared with full-length transcripts (0.5/174 and 3.3/132 FPKM), we hypothesize that these represent secondary fusions due to amplification. Five specimens (4 TCGA, 1 fluorescence in situ hybridization) had concurrent chromosome 3p copy number loss or VHL deletion. However, these did not resemble clear cell RCC, had negative carbonic anhydrase IX labeling, lacked VHL mutation, and had papillary or unclassified histology (2/4 had gain of chromosome 7 or 17). One tumor each had somatic FH mutation and SMARCB1 mutation. Chromosome 6p amplification including TFEB is a previously unrecognized cytogenetic alteration in RCC, associated with heterogenous tubulopapillary eosinophilic and clear cell histology. The combined constellation of features does not fit cleanly into an existing tumor category (unclassified), most closely resembling papillary or translocation RCC. The tendency for high tumor stage, varied tubulopapillary morphology, and a subset with melanocytic marker positivity suggests the possibility of a unique tumor type, despite some variation in appearance and genetics.

Characteristics of the Peritumoral Pseudocapsule Vary Predictably With Histologic Subtype of T1 Renal Neoplasms.

OBJECTIVE To determine characteristics of the peritumoral pseudocapsule (PC) between renal tumor subtypes. METHODS The peritumoral PCs of 160 pT1 renal tumors were examined, including 60 clear cell renal cell carcinomas (RCCs), 50 papillary RCCs, 25 chromophobe RCCs, and 25 oncocytoma. Pathologic features (presence or absence of PC, mean thickness, continuity, and invasion by tumor) were analyzed. PC thickness was measured using an ocular micrometer to the nearest 1/10 mm. RESULTS A complete PC was found in 77% of clear cell tumors, 74% of papillary, 28% of chromophobe, and 4% of oncocytomas. Tumor PC was present but incomplete in 18% of clear cell, 18% of papillary, 44% of chromophobe, and 56% of oncocytoma. The PC was entirely absent in no clear cell tumors, 6% of papillary, 28% of chromophobe, and 40% of oncocytoma. Mean PC thickness and presence of invasion beyond the PC differed significantly by tumor subtype. Clear cell RCC possessed the thickest PC showing invasion through the capsule in 8% of tumors compared to 30% of papillary tumors. Complete PC invasion was not seen in chromophobe RCC or renal oncocytoma. Oncocytoma and chromophobe RCC characteristically exhibited an incomplete or absent PC. CONCLUSION The characteristics of peritumoral PC vary predictably with histologic subtype of renal neoplasms. Clear cell RCC shows the most consistent PC, with a lower rate of invasion beyond it compared to papillary RCC. Chromophobe and oncocytoma characteristically have an incomplete or absent PC.

#InSituPathologists: how the #USCAP2015 meeting went viral on Twitter and founded the social media movement for the United States and Canadian Academy of Pathology

Professional medical conferences over the past five years have seen an enormous increase in the use of Twitter in real-time, also known as “live-tweeting”. At the United States and Canadian Academy of Pathology (USCAP) 2015 annual meeting, 24 attendees (the authors) volunteered to participate in a live-tweet group, the #InSituPathologists. This group, along with other attendees, kept the world updated via Twitter about the happenings at the annual meeting. There were 6,524 #USCAP2015 tweets made by 662 individual Twitter users; these generated 5,869,323 unique impressions (potential tweet-views) over a 13-day time span encompassing the dates of the annual meeting. Herein we document the successful implementation of the first official USCAP annual meeting live-tweet group, including the pros/cons of live-tweeting and other experiences of the original #InSituPathologists group members. No prior peer-reviewed publications to our knowledge have described in depth the use of an organized group to “live-tweet” a pathology meeting. We believe our group to be the first of its kind in the field of pathology.

Primary Cystic Trophoblastic Tumor of the Testis: A Study of 14 Cases

Cystic trophoblastic tumor (CTT) has been described in postchemotherapy retroperitoneal lymph node dissections of patients with testicular germ cell tumors. Prognostically, this lesion is similar to teratoma and no further treatment is required after surgery in the absence of other components. CTT has not, however, been reported in the testis. We identified 14 CTTs in the treated (4) and untreated (9; no information for 1 patient) testes of patients 15 to 43 years old (median, 25) with mixed germ cell tumors. The CTT was a minor component (<1% to 10%) and associated with teratoma (14), embryonal carcinoma (7), yolk sac tumor (7), seminoma (1), and choriocarcinoma (1). At follow-up, CTT and teratoma were also found in 2 subsequent resections (spermatic cord and pelvis mass) in 2 patients. The CTTs were not grossly distinct but on microscopic examination were cystic to partly solid, with cysts often containing fibrinoid material and lined by mononucleated squamoid cells with eosinophilic to pale, frequently vacuolated cytoplasm and having pleomorphic nuclei with dense, often smudged chromatin. Mitotic activity was inconspicuous. Immunostains for hCG (6/6), inhibin (6/6), and p63 (2/6) were focally positive. The pathogenesis of CTT is not completely understood. As untreated patients without choriocarcinoma may have CTT in the testis, it is suggested that testicular CTT represents a form of regressed choriocarcinoma or a late morphologic phase in the transformation of choriocarcinoma to teratoma.