Brincidofovir (CMX001) Toxicity Associated With Epithelial Apoptosis and Crypt Drop Out in a Hematopoietic Cell Transplant Patient: Challenges in Distinguishing Drug Toxicity From GVHD.

Brincidofovir (CMX001) is an oral agent with activity against double-strand DNA viruses undergoing clinical trials in immunocompromised patients. We report a patient clinically diagnosed with brincidofovir-related gastrointestinal (GI) toxicity and his histologic findings. A 2-year-old boy with medulloblastoma undergoing autologous hematopoietic cell transplantation developed adenovirus viremia 9 days posttransplant. After initial treatment with intravenous cidofovir he was started on oral brincidofovir as part of a clinical trial. He developed hematochezia, anorexia, and emesis 11 weeks later. Sigmoid colon biopsy showed marked crypt drop out, moderate epithelial apoptosis, and lamina propria edema. The pathologic diagnosis was drug-related injury versus infection. Brincidofovir toxicity was diagnosed clinically and the drug was discontinued. His GI symptoms improved in 2 weeks with supportive care and octreotide. Brincidofovir causes GI toxicity and histologically demonstrates epithelial apoptosis and crypt injury, similar to graft versus host disease and mycophenolate mofetil toxicity.

Use of the National Institutes of Health Consensus Guidelines Improves the Diagnostic Sensitivity of Gastrointestinal Graft-Versus-Host Disease.

CONTEXT: - Graft-versus-host disease of the gastrointestinal tract is a common complication of hematopoietic stem cell transplant associated with significant morbidity and mortality. Accurate diagnosis can be difficult and is a truly clinicopathologic endeavor. OBJECTIVES: - To assess the diagnostic sensitivity of gastrointestinal graft-versus-host disease using the 2015 National Institutes of Health (NIH) histology consensus guidelines and to analyze histologic findings that support the guidelines. DESIGN: - Patients with allogeneic hematopoietic stem cell transplants were identified via a retrospective search of our electronic medical records from January 1, 2005, to January 1, 2011. Endoscopies with available histology were reviewed by 2 pathologists using the 2015 NIH guidelines. The clinical diagnosis was used as the gold standard. A nontransplant set of endoscopic biopsies was used as a control. RESULTS: - Of the 250 total endoscopies, 217 (87%) had a clinical diagnosis of gastrointestinal graft-versus-host disease. Use of the NIH consensus guidelines showed a sensitivity of 86% and a specificity of 65%. Thirty-seven of 58 (64%) cases with an initial false-negative histopathologic diagnosis were diagnosed as graft-versus-host disease on our review. CONCLUSIONS: - Use of the NIH histology consensus guidelines results in a high sensitivity and specificity, thereby decreasing false-negatives. Additionally, use of the NIH guidelines aids in creating uniformity and diagnostic clarity. Correlation with clinical and laboratory findings is critical in evaluating the differential diagnosis and to avoid false-positives. As expected, increased apoptosis with decreased inflammation was associated with a pathologic diagnosis of graft-versus-host disease and supports the NIH guidelines.

Late Gastrointestinal Complications of Allogeneic Hematopoietic Stem Cell Transplantation in Adults.

Gastrointestinal (GI) complications including graft-versus-host disease (GVHD) are a major cause of morbidity and mortality in allogenic stem transplant recipients. Although several studies have previously looked into the acute GI complications, fewer smaller studies have reported late complications. In this large study we focus on the late (100 days post-transplant) GI complications in allogenic stem transplant recipients. In this single-center, retrospective study of all adult allogenic stem cell transplant recipients who had their transplant at Duke University over a 6-year period, 479 patients underwent allogenic stem cell transplant, of whom 392 recipients survived for at least 100 days post-transplant. Late GI symptoms were noted in 71 patients, prompting endoscopic evaluation. The primary endpoint of our study was the diagnosis of GI-GVHD based on endoscopic findings, whereas overall survival and nonrelapse mortality were the secondary endpoints. Of the 71 patients who underwent endoscopy, 45 (63%) had GI-GVHD. Of these 45 patients, 39 (87%) had late acute GVHD, 1 (2%) had chronic GVHD, and 5 patients (11%) had overlap disease. Of the patients who did not have GVHD, the symptoms were mostly related to infectious and inflammatory causes. Less common causes included drug toxicity, food intolerance, disease relapse, and motility issues. In a multivariate analysis the factors most indicative of GI-GVHD were histologic findings of apoptosis on the tissue specimen (odds ratio, 2.35; 95% confidence interval, 1.18 to 4.70; P = .015) and clinical findings of diarrhea (odds ratio, 5.43; 95% confidence interval, 1.25 to 23.54; P = .024). The median survival time from the first endoscopy was 8.5 months. The incidence of nonrelapse mortality at 6 months was 31% in patients with GI-GVHD and 19% in patients without GI-GVHD (P = .42). All patients with GI-GVHD were on steroid therapy, and 31% of them received total parenteral nutrition. In our population close to one-fifth of allogenic transplant recipients experienced late GI complications, warranting endoscopic evaluation. Most of these patients were found to have GI-GVHD that had a high incidence of nonrelapse mortality at 6 months and close to one-third of these patients needed total parenteral nutrition.

Primary high-grade neuroendocrine carcinoma emerging from an adenomatous polyp in the setting of familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) is a rare inherited syndrome that is characterised by innumerable adenomas of the colon and rectum, a high risk of colorectal cancer and a variety of extracolonic manifestations. FAP presents as hundreds to thousands of colonic adenomas beginning in adolescence. The syndrome is associated with less than 1% of all colorectal cancer cases, but there is a nearly 100% lifetime risk of colorectal cancer in individuals with FAP. This case demonstrates a 60-year-old man with FAP who developed high-grade neuroendocrine carcinoma with glandular and squamous differentiation, and regional lymph node and liver metastases. Early diagnosis of FAP is of the utmost importance to start screening colonoscopies to assess disease burden, perform polypectomies and to make management decisions. Neuroendocrine carcinomas rarely occur in patients with FAP, and awareness of this association among general medical physicians and pathologists is essential for the diagnosis and care of these patients.

Dual S-100-AE1/3 Immunohistochemistry to Detect Perineural Invasion in Nonmelanoma Skin Cancers.

Background. Perineural invasion (PNI) is an adverse prognostic histologic finding and increases the risk of local recurrence and metastasis. Objective. We aimed to determine if dual immunohistochemical (IHC) staining with S-100 and AE1/3 would increase the detection of PNI on nonmelanoma skin cancers (NMSCs). Methods. We collected 45 specimens of NMSCs in which there was clinical suspicion for PNI. Two dermatopathologists independently reviewed the tumors for the unequivocal presence of PNI. Results. Unequivocal PNI was present on 10 of the 45 tumors by H&E staining and on 15 of the 45 tumors by IHC staining. Large nerves (>0.1 mm) were involved in 3 of 10 H&E-stained cases and 3 of 15 IHC-stained cases, with 2 of the 4 cases demonstrating large nerve involvement with both staining methods. Of the 8 cases of PNI detected only on IHC, 7 were small nerves (≤0.1 mm). Limitations. All cases were selected because they were clinically suspicious for PNI, and this may be considered selection bias. Conclusions. PNI detection may be increased using dual S-100 and AE1/3 staining, but the majority of additional cases detected were small nerves. The clinical significance, given the small size of the involved nerves, is unclear.