Eyas M. Hattab

Tertiary Gleason Pattern 5 is a Powerful Predictor of Biochemical Relapse in Patients With Gleason Score 7 Prostatic Adenocarcinoma

PURPOSE In radical prostatectomy specimens Gleason score 7 is among the most commonly assigned scores for prostate carcinoma accounting for 30% to 50% of cases. Gleason score 7 is different from other more differentiated prostate carcinomas (tumors of Gleason scores 5 and 6) with a significantly worse outcome and higher rate of recurrence. Nonetheless, Gleason score 7 tumors are heterogeneous. In this study we examined the differences in clinical outcome between primary Gleason grade 3 and 4 tumors in patients who underwent radical prostatectomy, and determined the influence of tertiary Gleason pattern 5 on patient outcome. MATERIALS AND METHODS A total of 504 patients underwent radical prostatectomy for prostate cancer and 228 of the patients (45%) had a Gleason score of 7. Cases were analyzed for a variety of clinical and pathological parameters. The influence of primary Gleason pattern and tertiary Gleason pattern 5 on patient outcome was assessed in the Cox regression model. RESULTS Among 228 patients with Gleason score 7 prostatic adenocarcinoma, 91 (40%) had a primary Gleason pattern 4 and 137 (60%) had primary Gleason pattern 3. Patients of the former group were more likely to have a higher pathological stage (p = 0.003), more likely to have PSA recurrence (p = 0.02) and more likely to have a tertiary Gleason pattern 5 (p <0.0001). A total of 37 (41%) patients with primary Gleason 4 had a tertiary Gleason pattern 5, whereas only 13 (9%) patients with primary Gleason 3 had a tertiary Gleason pattern 5. In the Cox regression model controlling for tumor stage and surgical margin status, the primary Gleason pattern was not an independent predictor of PSA recurrence (p = 0.80), whereas the presence of tertiary Gleason pattern 5 was a significant predictor of PSA recurrence (hazard ratio 2.10, 95% CI 1.24-3.55, p = 0.006). Five-year PSA recurrence-free survival was 70% for patients without a tertiary Gleason pattern 5 compared to 19% for those patients with a tertiary Gleason pattern 5. CONCLUSIONS Among patients with Gleason score 7, primary Gleason grade 4 indicates a likelihood of higher tumor stage and higher probability of PSA recurrence than does primary pattern 3. However, it does not independently predict a worse outcome after controlling for other known prognostic parameters associated with disease progression. Regardless of whether the primary Gleason pattern is 3 or 4, a tertiary Gleason pattern 5 is the strongest predictor of a worse outcome in patients with Gleason grade 7 prostatic adenocarcinoma. Therefore, tertiary pattern 5 should be reported in radical prostatectomy specimens.

Primary testicular diffuse large B-cell lymphoma belongs to the nongerminal center B-cell-like subgroup: a study of 18 cases

The most common type of primary testicular lymphoma is diffuse large B-cell type, which has the potential for aggressive clinical behavior. Diffuse large B-cell lymphoma can be further subclassified into two major prognostic categories: germinal center B-cell-like and nongerminal center B-cell-like. Such distinction is made possible using the immunohistochemical expression of CD10, Bcl-6 and MUM1. The aim of this study was to stratify primary testicular lymphoma of the diffuse large B-cell type according to this scheme. Immunohistochemical stains for CD10, Bcl-6 and MUM1 were performed on 18 cases of primary testicular lymphoma of diffuse large B-cell type. Subclassification was carried out as previously described where CD10 and/or Bcl-6 positivity and negativity for MUM1 were considered indicative of germinal center B-cell-like type and the opposite expression as nongerminal center B-cell-like type. The proliferative activity was determined using immunostaining with the Ki-67 antibody. Of 18 cases, 16 (89%) were found to belong to the nongerminal center B-cell-like type. Two cases (11%) were classified as germinal center B-cell-like type; one had a CD10-positive, Bcl-6-positive and MUM1-negative profile, and the other was CD10 negative, Bcl-6 positive and MUM1 negative. The former occurred in a 38-year-old patient who was human immunodeficiency virus positive. All the cases expressed high proliferative activity (≥50% Ki-67 labeling). We conclude that most (89%) primary testicular lymphomas of the diffuse large B-cell type belong to the nongerminal center B-cell-like subgroup and have high proliferative activity.

Atypical ductal hyperplasia: interobserver and intraobserver variability

Interobserver reproducibility in the diagnosis of benign intraductal proliferative lesions has been poor. The aims of the study were to investigate the inter- and intraobserver variability and the impact of the addition of an immunostain for high- and low-molecular weight keratins on the variability. Nine pathologists reviewed 81 cases of breast proliferative lesions in three stages and assigned each of the lesions to one of the following three diagnoses: usual ductal hyperplasia, atypical ductal hyperplasia and ductal carcinoma in situ. Hematoxylin and eosin slides and corresponding slides stained with ADH-5 cocktail (cytokeratins (CK) 5, 14. 7, 18 and p63) by immunohistochemistry were evaluated. Concordance was evaluated at each stage of the study. The interobserver agreement among the nine pathologists for diagnosing the 81 proliferative breast lesions was fair (κ-value=0.34). The intraobserver κ-value ranged from 0.56 to 0.88 (moderate to strong). Complete agreement among nine pathologists was achieved in only nine (11%) cases, at least eight agreed in 20 (25%) cases and seven or more agreed in 38 (47%) cases. Following immunohistochemical stain, a significant improvement in the interobserver concordance (overall κ-value=0.50) was observed (P=0.015). There was a significant reduction in the total number of atypical ductal hyperplasia diagnosis made by nine pathologists after the use of ADH-5 immunostain. Atypical ductal hyperplasia still remains a diagnostic dilemma with wide variation in both inter- and intraobserver reproducibility among pathologists. The addition of an immunohistochemical stain led to a significant improvement in the concordance rate. More importantly, there was an 8% decrease in the number of lesions classified as atypical ductal hyperplasia in favor of usual hyperplasia; in clinical practice, this could lead to a decrease in the number of surgeries carried out for intraductal proliferative lesions.

Impaired growth and neurological abnormalities in branched-chain α-keto acid dehydrogenase kinase-deficient mice

The BCKDH (branched-chain alpha-keto acid dehydrogenase complex) catalyses the rate-limiting step in the oxidation of BCAAs (branched-chain amino acids). Activity of the complex is regulated by a specific kinase, BDK (BCKDH kinase), which causes inactivation, and a phosphatase, BDP (BCKDH phosphatase), which causes activation. In the present study, the effect of the disruption of the BDK gene on growth and development of mice was investigated. BCKDH activity was much greater in most tissues of BDK-/- mice. This occurred in part because the E1 component of the complex cannot be phosphorylated due to the absence of BDK and also because greater than normal amounts of the E1 component were present in tissues of BDK-/- mice. Lack of control of BCKDH activity resulted in markedly lower blood and tissue levels of the BCAAs in BDK-/- mice. At 12 weeks of age, BDK-/- mice were 15% smaller than wild-type mice and their fur lacked normal lustre. Brain, muscle and adipose tissue weights were reduced, whereas weights of the liver and kidney were greater. Neurological abnormalities were apparent by hind limb flexion throughout life and epileptic seizures after 6-7 months of age. Inhibition of protein synthesis in the brain due to hyperphosphorylation of eIF2alpha (eukaryotic translation initiation factor 2alpha) might contribute to the neurological abnormalities seen in BDK-/- mice. BDK-/- mice show significant improvement in growth and appearance when fed a high protein diet, suggesting that higher amounts of dietary BCAA can partially compensate for increased oxidation in BDK-/- mice. Disruption of the BDK gene establishes that regulation of BCKDH by phosphorylation is critically important for the regulation of oxidative disposal of BCAAs. The phenotype of the BDK-/- mice demonstrates the importance of tight regulation of oxidative disposal of BCAAs for normal growth and neurological function.

Chromosome 12p abnormalities in dysgerminoma of the ovary: a FISH analysis.

Dysgerminoma is the most common malignant ovarian germ cell tumor and shares histological and immunophenotypical features with its testicular counterpart, seminoma. Chromosome 12p abnormalities are genetic hallmarks of testicular seminomas. Little is known about these genetic changes in dysgerminoma. We performed dual color fluorescence in situ hybridization (FISH) analyses with a centromeric α-satellite probe for chromosome 12 and a subtelomeric probe for 12p on paraffin-embedded tissue sections from 21 dysgerminomas and two gonadoblastomas. Chromosome 12p abnormalities were detected in 81% of dysgerminomas. In all, 57% of cases had only isochromosome 12p and 5% had only 12p overrepresentation. In all, 19% had both isochrome 12p and 12p overrepresentation. Gonadoblastomas were negative for isochromosome 12p or 12p overrepresentation. Chromosome 12p abnormalities are common in dysgerminoma of the ovary. FISH analyses for chromosome 12p abnormalities may be a useful diagnostic adjunct for confirming the diagnosis of dysgerminoma and for distinguishing it from nongerm cell malignancies that enter into the differential diagnosis.

Lipid and metabolite profiles of human brain tumors by desorption electrospray ionization-MS

Significance Brain tumors can lead to a significant source of morbidity and mortality. The primary treatment is microsurgical resection, and the extent of resection is associated with length of survival. Unfortunately, reliable intraoperative tools for diagnosis and safe maximal resection of the tumor mass are lacking. Mass spectra (lipid and metabolite profiles) can be used to distinguish between healthy and diseased tissues by comparison of patterns of peak intensities using multivariate statistics. This experiment can be done on a timescale amenable to intraoperative analysis using tissue smears. These data can provide surgeons with near real-time pathologic information and guide the intraoperative resection of the tumor at the difficult to detect peritumoral borders. Examination of tissue sections using desorption electrospray ionization (DESI)-MS revealed phospholipid-derived signals that differ between gray matter, white matter, gliomas, meningiomas, and pituitary tumors, allowing their ready discrimination by multivariate statistics. A set of lower mass signals, some corresponding to oncometabolites, including 2-hydroxyglutaric acid and N-acetyl-aspartic acid, was also observed in the DESI mass spectra, and these data further assisted in discrimination between brain parenchyma and gliomas. The combined information from the lipid and metabolite MS profiles recorded by DESI-MS and explored using multivariate statistics allowed successful differentiation of gray matter (n = 223), white matter (n = 66), gliomas (n = 158), meningiomas (n = 111), and pituitary tumors (n = 154) from 58 patients. A linear discriminant model used to distinguish brain parenchyma and gliomas yielded an overall sensitivity of 97.4% and a specificity of 98.5%. Furthermore, a discriminant model was created for tumor types (i.e., glioma, meningioma, and pituitary), which were discriminated with an overall sensitivity of 99.4% and a specificity of 99.7%. Unsupervised multivariate statistics were used to explore the chemical differences between anatomical regions of brain parenchyma and secondary infiltration. Infiltration of gliomas into normal tissue can be detected by DESI-MS. One hurdle to implementation of DESI-MS intraoperatively is the need for tissue freezing and sectioning, which we address by analyzing smeared biopsy tissue. Tissue smears are shown to give the same chemical information as tissue sections, eliminating the need for sectioning before MS analysis. These results lay the foundation for implementation of intraoperative DESI-MS evaluation of tissue smears for rapid diagnosis.

Expression of CD117 (c-kit) receptor in dysgerminoma of the ovary: diagnostic and therapeutic implications.

The proto-oncogene c-kit encodes a tyrosine kinase receptor, c-kit (CD117), which has been implicated in the development of a number of human malignancies. While the preferential expression of this protein has been well documented in testicular seminomas, there is little data concerning its expression in dysgerminomas of the ovary. We examined the expression of c-kit in 30 cases of ovarian dysgerminomas using immunohistohemical staining with a polyclonal anti-CD117 antibody. Staining was graded in a semiquantitative manner as follows: negative (no staining), 1+ (1–10% staining), 2+ (10–29% staining), 3+ (30–50% staining), or 4+ (>50% staining). Of the 30 cases examined, 26 (87%) demonstrated immunoreactivity for CD117. In total, 10 (33%) demonstrated 4+ staining; 9 (30%) demonstrated 3+ staining; 3 (10%) demonstrated 2+ staining; 4 (13%) demonstrated 1+ staining; and 4 (13%) demonstrated no staining. In conclusion, CD117 immunoreactivity was detected in 87% of ovarian dysgerminomas, a finding that correlates with previously reported frequencies of CD117 expression in seminomas (78–100%). Thus, antibodies to c-kit may be a useful diagnostic marker for ovarian dysgerminoma. Although the prognosis of patients with dysgerminoma is generally good, this receptor could potentially serve as a target for site-specific immunotherapy as an alternative and/or complement to conventional treatment options.

Polysomy of chromosomes 1 and/or 19 is common and associated with less favorable clinical outcome in oligodendrogliomas: Fluorescent in situ hybridization analysis of 84 consecutive cases

Abstract It is well established that the combined del(1)(p36) and del(19)(q13) is a positive prognostic molecular event in oligodendroglial tumors. However, very little is known about the frequency or impact of polysomy status for chromosomes 1/19. We examined 84consecutive pure oligodendrogliomas (68 World Health Organization [WHO] grade II and 16 WHO grade III) and analyzed them for del(1)(p36) and del(19)(q13) by fluorescent in situ hybridization. Polysomy status was recorded with accompanying deletion status, WHO grade, recurrence-free survival, and overall survival. Codeletion of 1p/19q was detected in 48% of cases and correlated with superior patient survival (p < 0.01), as expected. Of 84 cases, 36 (43%) showed polysomy of chromosome 1, 30 (36%) demonstrated polysomy of chromosome 19, and 28 (33%) had copolysomies of chromosomes 1/19. The presence of polysomy of either/or both chromosomes, regardless of deletion status, correlated with younger patient age at initial diagnosis (p < 0.01). Combined polysomy was associated with higher histologic tumor grade (p = 0.04) and conferred poor survival likelihood (p = 0.03). We conclude that polysomy of 1 and/or 19 is a relatively frequent occurrence in oligodendrogliomas and usually confers an unfavorable outcome.

Primitive neuroectodermal tumors in patients with testicular germ cell tumors usually resemble pediatric-type central nervous system embryonal neoplasms and lack chromosome 22 rearrangements

Primitive neuroectodermal tumors (PNETs) are one of the most frequent types of ‘non-germ cell’ tumor in patients with testicular germ cell tumors and have a guarded prognosis when present in metastatic sites after cisplatin-based chemotherapy. Improved treatments, including targeted therapy, require understanding the biology of these neoplasms. We therefore analyzed the morphologic, immunohistochemical and molecular biologic features of 14 PNETs from 14 patients with concurrent or previous testicular germ cell tumors; 12 tumors were from metastatic sites and 2 were primary in the testis. Using standard light microscopic criteria for central nervous system and peripheral PNETs, we classified nine tumors as medulloepithelioma, three as medulloblastoma/supratentorial PNET, one as neuroblastic tumor with abundant neuropil and true rosettes and one as small cell embryonal tumor/PNET (Ewing sarcoma-like). Immunostains directed against INI1, CD57, S-100 protein, NeuN, WT1, neurofilament, CD99, GFAP, synaptophysin, chromogranin, AE1/AE3 cytokeratin, Fli-1 and collagen IV were performed for each case. INI1 was diffusely and strongly positive in all tumors whereas the other stains, except for cytoplasmic WT1 (which showed substantial reactivity in most tumors), were mostly focal to negative, including CD99 (eight negative, six focal) and Fli-1 (all negative). The most consistently reactive ‘neuroendocrine’ marker was CD57. Each case was also analyzed for chromosome 22 rearrangements using a FISH-based break-apart probe method. Only 1 tumor, classified as medulloepithelioma, was scored positive for chromosome 22 translocation (22% rearranged cells) and the remaining 13 were negative, including the one case that resembled peripheral PNET. We conclude that PNETs derived from testicular germ cell tumors mostly resemble central nervous system PNETs and generally lack the chromosome 22 translocation of peripheral PNETs. Future treatment strategies should take these findings into account.

Most primary central nervous system diffuse large B-cell lymphomas occurring in immunocompetent individuals belong to the nongerminal center subtype: a retrospective analysis of 31 cases.

Primary central nervous system lymphomas are rare neoplasms characterized by a dismal prognosis relative to other extranodal lymphomas. Approximately 98% of primary central nervous system lymphomas are of B-cell origin, and most belong to the diffuse large B-cell type. Recently, diffuse large B-cell lymphomas have been subcategorized into germinal center and nongerminal center types based on gene expression profiles and immunohistochemical expression of CD10, Bcl-6, and MUM1. Studies have shown that the overall survival rate of the germinal center group is better than that of the nongerminal center lymphomas. In this study, 31 cases of primary central nervous system lymphomas of the diffuse large B-cell type were retrieved, reviewed, and immunostained for CD10, Bcl-6, MUM1, and Ki-67. Subclassification was carried out as described earlier, where CD10 and/or Bcl-6 positivity and negativity for MUM1 were considered characteristic of germinal center subtype and the opposite expression of nongerminal center subtype. Furthermore, the proliferative activity was semiquantitatively assessed using percent positive cells staining with Ki-67. Of the 31 cases examined, 26 (84%) were found to belong to the nongerminal center type. The Ki-67 index in these 26 cases ranged from 30 to 90% (mean, 69%). Five cases were categorized as the germinal center subtype. They had an Ki-67 index between 70 and 90% (mean, 78%). Interestingly, none of our patients were known to be HIV positive. One patient had a 10-year history of orthotopic liver transplant. We also performed fluorescence in situ hybridization analysis on formalin-fixed material and found that 38% of the cases where tissue was available had abnormalities of MYC/IGH and/or IGH/BCL2. We conclude that most primary central nervous system diffuse large B-cell lymphomas are of the nongerminal center origin. Regardless of the germinal center status, all cases showed a high proliferative rate. A statistically significant difference in the overall survival between the two groups was not seen.