A Combined Biomarker of Bright CD38 and MYC ≥55% Is Highly Predictive of Double-/Triple-Hit High-Grade B-Cell Lymphoma.

OBJECTIVES: Diagnosis of high-grade B-cell lymphoma with MYC and BCL2 or BCL6 rearrangements (double-/triple-hit lymphoma [DTHL]) appears to mandate fluorescence in situ hybridization (FISH) testing for all large B-cell lymphoma (LBCL). Given the low incidence of DTHL, we aimed to identify flow cytometry (FC) and immunohistochemistry (IHC) features of DTHL that could be used to develop an optimal screening strategy. This combined FC-IHC approach has not yet been studied. METHODS: We compared features of 40 cases of DTHL and 39 cases of diffuse LBCL (DLBCL) without MYC rearrangement. RESULTS: Bright CD38 expression (CD38bright) by FC, high MYC expression (≥55%), and double-expressor phenotype by IHC were significantly associated with DTHL. The biomarker combining FC and IHC, CD38bright and/or MYC ≥55%, was superior to FC and IHC markers alone in predicting DTHL. Restricting FISH testing to approximately 25% of LBCL based on CD38brightand/or MYC ≥55% would detect approximately 95% of DTHL-BCL2 and approximately 75% of DHL-BCL6. CONCLUSIONS: Our study demonstrated that the novel biomarker of CD38bright and/or MYC ≥55% is highly predictive of DTHL. Awareness of the advantages and limitations of this screening strategy would facilitate development of a rational diagnostic workflow to provide high-quality patient care.

Bright CD38 Expression by Flow Cytometric Analysis Is a Biomarker for Double/Triple Hit Lymphomas with a Moderate Sensitivity and High Specificity.

BACKGROUND: High-grade B-cell lymphomas (HGBCL) with MYC and BCL2 or/and BCL6 rearrangements (R), so-called double/triple-hit lymphomas (DH/THL), are uncommon, clinically aggressive lymphomas that require a prompt diagnosis. We aim to identify flow cytometric immunophenotypic (IP) features of DH/THL that may aid in triaging these cases followed by a timely confirmatory cytogenetic study. METHODS: We compared the IP features of 43 cases of DH/THL to those of 55 cases of single-hit lymphoma (SHL) and 59 cases of diffuse large B-cell lymphoma (DLBCL) without MYC-R (MYCneg DLBCL). We analyzed the expression patterns of CD10, CD19, CD20, CD38, and surface immunoglobulin light chain in lymphoma cells. RESULTS: Bright CD38 expression (CD38bright ) analyzed either qualitatively or semi-quantitatively was more common in DH/THL (56%) than in MYCneg DLBCL (17%) but less common compared to SHL (82%), indicating that CD38bright can serve as a biomarker for DH/THL. Additionally, CD38bright may be a better indicator for predicting DH/THL-BCL2 than DHL-BCL6, and very bright CD38 expression was exclusive to MYC rearranged lymphomas. The expression patterns of other markers were similar among these lymphoma groups. CONCLUSIONS: CD38bright is a biomarker associated with DH/THL with a moderate sensitivity (~50%) and high specificity (~90%). While this marker cannot be used as a screening tool, awareness of this correlation may aid in expediting the diagnosis and prioritizing FISH testing in resource limited settings or situations when samples are limited. Future studies to combine immunohistochemical markers are needed to further enhance the predictive power of CD38bright in diagnosing DH/THL. © 2019 International Clinical Cytometry Society.

Racial variation in prostate needle biopsy templates directed anterior to the peripheral zone.

OBJECTIVES: African Americans (AA) have been reported to have both increased incidence and increased aggressiveness of prostate cancer (PCa) located anterior to the peripheral zone (APZ). We sought to evaluate the utility of prostate biopsies directed toward the APZ in a predominantly AA cohort. METHODS AND MATERIALS: We reviewed all patients with PCa found on biopsy schema that included needle biopsies directed at both the peripheral zone (PZ) and APZ from 2010 to 2014. Self-identified race was recorded for all patients. To evaluate the reliability of APZ-directed prostate biopsies, we performed pathologic secondary review of 25 radical prostatectomy specimens. A series of the Mann-Whitney U and Chi-square tests were used to compare variables. RESULTS: We identified 398 men, of which 277 (70%) were AA. Compared with non-AA, AA had more National Comprehensive Cancer Network-defined intermediate or high-risk (50% vs. 39%, P = 0.25) PCa. Most patients had PCa limited to the PZ only (n = 190) or in both the PZ and APZ (n = 191). For 17 patients (4%), PCa was limited only to the APZ core(s), 14 (5%) AA vs. 3 (2%) non-AA (P = 0.24). Most of these 17 patients (n = 14, 82%) had Gleason 6 disease. Patients with PCa in both the PZ and APZ had higher serum prostate-specific antigen, prostate-specific antigen density, volume of disease, and increased grade and National Comprehensive Cancer Network category (all P<0.01). Of these patients, there were no differences in race (AA = 135, 71% vs. non-AA = 56, 29%; P = 0.48). In only 21 men (11%), without racial variation, APZ tumor grade was greater than PZ. Radical prostatectomy and APZ-directed biopsies demonstrated a concordance rate of 80% (20/25), false positive rate of 8% (2/25), and false negative rate of 12% (3/25). CONCLUSIONS: APZ-directed prostate biopsies are rarely the sole location of PCa and do not show a clear racial predilection. In those men with PCa identified in both regions, the APZ biopsy did not frequently change treatment recommendations. Biopsies directed at the APZ are not of greater benefit to AA than non-AA.

Lack of mutation-histopathology correlation in a patient with Proteus syndrome.

Proteus syndrome (PS) is characterized by progressive, disproportionate, segmental overgrowth, and tumor susceptibility caused by a somatic mosaic AKT1 activating mutation. Each individual has unique manifestations making this disorder extremely heterogeneous. We correlated three variables in 38 tissue samples from a patient who died with PS: the gross affection status, the microscopic affection status, and the mutation level. The AKT1 mutation was measured using a PCR-based RFLP assay. Thirteen samples were grossly normal; six had detectable mutation (2-29%) although four of these six were histopathologically normal. Of the seven grossly normal samples that had no mutation, only four were histologically normal. The mutation level in the grossly abnormal samples was 3-35% and all but the right and left kidneys, skull, and left knee bone, with mutation levels of 19%, 15%, 26%, and 17%, respectively, had abnormal histopathology. The highest mutation level was in a toe bone sample whereas the lowest levels were in the soft tissue surrounding that toe, and an omental fat nodule. We also show here that PS overgrowth can be caused by cellular proliferation or by extracellular matrix expansion. Additionally, papillary thyroid carcinoma was identified, a tumor not previously associated with PS. We conclude that gross pathology and histopathology correlate poorly with mutation levels in PS, that overgrowth can be mediated by cellular proliferation or extracellular matrix expansion, and that papillary thyroid carcinoma is part of the tumor susceptibility of PS. New methods need to be developed to facilitate genotype-phenotype correlation in mosaic disorders. © 2016 Wiley Periodicals, Inc.

The first association of a primary amebic meningoencephalitis death with culturable Naegleria fowleri in tap water from a US treated public drinking water system.

BACKGROUND: Naegleria fowleri is a climate-sensitive, thermophilic ameba found in warm, freshwater lakes and rivers. Primary amebic meningoencephalitis (PAM), which is almost universally fatal, occurs when N. fowleri-containing water enters the nose, typically during swimming, and migrates to the brain via the olfactory nerve. In August 2013, a 4-year-old boy died of meningoencephalitis of unknown etiology in a Louisiana hospital. METHODS: Clinical and environmental testing and a case investigation were initiated to determine the cause of death and to identify potential exposures. RESULTS: Based on testing of cerebrospinal fluid and brain specimens, the child was diagnosed with PAM. His only reported water exposure was tap water; in particular, tap water that was used to supply water to a lawn water slide on which the child had played extensively prior to becoming ill. Water samples were collected from both the home and the water distribution system that supplied the home and tested; N. fowleri was identified in water samples from both the home and the water distribution system. CONCLUSIONS: This case is the first reported PAM death associated with culturable N. fowleri in tap water from a US treated drinking water system. This case occurred in the context of an expanding geographic range for PAM beyond southern states, with recent case reports from Minnesota, Kansas, and Indiana. This case also highlights the role of adequate disinfection throughout drinking water distribution systems and the importance of maintaining vigilance when operating drinking water systems using source waters with elevated temperatures.