A novel 5x multiplex immunohistochemical staining reveals PSMA as a helpful marker in prostate cancer with low p504s expression.

The ability to combine multiple immunohistochemical (IHC) markers within a single tissue section facilitates the evaluation and detection of co-expressions, while saving tissue. A newly developed 5x multiplex (MPX) IHC staining of five different IHC markers (Basal cell cocktail (34ßE12 + p63), p504s (SP116), ERG (EPR3864), Ki-67 (30-9), PSMA (EP192)) was applied on whole sections of n = 37 radical prostatectomies (RPE) including normal and cancerous tissue. Four different colors including brown, magenta, yellow and teal coded for different stainings, whereas magenta was used twice for nuclear Ki-67 and cytosolic / membranous PSMA. The staining of multiplex IHC was compared to single stains of ERG, PSMA and p504s. The proper staining of the basal cell cocktail and Ki-67 could be assessed by internal positive controls in the multiplex staining. The proportion of PSMA and p504s expression revealed a significant correlation between multiplex and single stains (p < 0.01) as well as a concordant staining pattern for ERG (n = 14 prostate cancers were identified ERG positive with both methods). Our proof of concept study demonstrates a robust staining pattern of all five different antibodies with this newly developed 5x MPX IHC. This approach facilitates the recognition of prostate cancer, in particular by adding PSMA in cases with low p504s expression.

Performance comparison of anti-p504s (SP116) Rabbit Monoclonal Primary Antibody vs. Monoclonal Rabbit Anti-Human AMACR clone 13H4 when duplexed with VENTANA Basal Cell Cocktail (34ßE12+p63) as a diagnostic aid for prostatic adenocarcinoma using immunohistochemistry.

Alpha-methylacyl-coenzyme A-racemase (AMACR), also known as p504s, is overexpressed in prostatic adenocarcinoma and is frequently used in combination with basal cell markers to aid in diagnosing difficult prostate adenocarcinoma cases. In this retrospective method comparison study, we examined the sensitivity and specificity of the ready-to-use anti-p504s (SP116) Rabbit Monoclonal Primary Antibody compared to the monoclonal rabbit anti-human AMACR clone 13H4 in prostatic adenocarcinoma samples. De-identified prostatic adenocarcinoma tissue samples were stained with either the SP116 or 13H4 antibody clone in combination with the VENTANA Basal Cell Cocktail (34ßE12+p63) and scored as positive or negative for prostatic adenocarcinoma. The scoring pathologist was blinded to the known historical diagnosis of each sample. The scoring pathologist correctly diagnosed each sample regardless of which p504s clone was used. Both assays using either clone were 100% concordant in their sensitivity and specificity. This study demonstrates that the ready-to-use anti-p504s (SP116) Rabbit Monoclonal Primary Antibody is equivalent to clone 13H4 concentrate when used according to package insert instructions in combination with the VENTANA Basal Cell Cocktail (34ßE12+p63) to aid pathologists in the diagnosis of prostatic adenocarcinoma.

CK20 versus AMACR and p53 immunostains in evaluation of Urothelial Carcinoma in Situ and Reactive Atypia.

Ancillary testing with immunohistochemistry has shown recent promise in the workup of equivocal bladder lesions. We read with interest the recent findings of Alston et al., who assessed the diagnostic utility of alpha-methylacyl-CoA racemase (AMACR) in comparison to cytokeratin 20 (CK20) in evaluation of atypia in challenging flat urothelial lesions in the differential between carcinoma in situ (CIS) and reactive atypia. AMACR was reported to be a somewhat more specific but less sensitive marker for CIS than CK20, though showing weaker intensity. Spurred by their report, with the knowledge that we had consistently and consecutively performed AMACR, CK20, and p53 on flat urothelial lesions challenging enough to reach intradepartmental consensus, we performed a retrospective review. Similarly, we found that AMACR was less sensitive (80%) and more specific (100%) than CK20, with the same caveat of less staining intensity. Additionally, our p53 review identified a significant rate (~ 27%) of equivocal/non-informative findings. Taken together, our experience in this consecutive cohort confirms the impression of Alston et al. regarding the utility and challenges of AMACR use, while highlighting challenges with p53, which we plan to use more sparingly prospectively.

Phase-Regulated Sensing Mechanism of MoS2 Based Nanohybrids toward Point-of-Care Prostate Cancer Diagnosis.

Alpha-methylacyl-CoA racemase (AMACR) has been proven to be consistently overexpressed in prostate cancer epitheliums, and is expected to act as a positive biomarker for the diagnosis of prostate carcinoma in clinical practice. Here, a strategy for specific determination of AMACR in real human serum by using an electrochemical microsensor system is presented. In order to implement the protocol, a self-organized nanohybrid consisting of metal nanopillars in a 2D MoS2 matrix is developed as material for the sensing interface. The testing signal outputs are strongly enhanced with the presence of the nanohybrids owing to that the metal pillars provide an efficient mass difussion and electron transfer path to the MoS2 film surface. Furthermore, the phase-regulated sensing mechanism over MoS2 is noticed and demonstrated by density functional theory calculation and experiments. The explored MoS2 based nanohybrids are employed for the fabrication of an electrochemical microsensor, presenting good linear relationship in both ng µL-1 and pg µL-1 ranges for AMACR quantification. The sampling analysis of human serum indicates that this microsensor has good diagnostic specificity and sensitivity toward AMACR. The proposed electrochemical microsensor system also demonstrates the advantages of convenience, cost-effectiveness, and disposability, resulting in a potential integrated microsystem for point-of-care prostate cancer diagnosis.

Does the addition of AMACR to CK20 help to diagnose challenging cases of urothelial carcinoma in situ?

BACKGROUND: Urothelial carcinoma in situ (CIS) in the bladder can be difficult to diagnose due to factors including procedural artifact, minimal tissue sampled, therapy-related changes, and various CIS growth patterns. Prior data has demonstrated an increase in alpha-methylacyl-CoA-racemase (AMACR) in urothelial CIS, but there is no information on its utility for diagnosing difficult cases. The aim of this investigation was to assess the expression of AMACR that was ordered on equivocal bladder cases during clinical practice. METHODS: Transurethral resections of the bladder in which AMACR and CK20 were performed during diagnostic workup were identified and cases with a final diagnosis of CIS (n = 22) or non-neoplastic urothelium (n = 30) were selected. Additionally, cases in which a diagnosis of CIS was rendered without IHC (n = 20) were selected and tested for AMACR expression. RESULTS: Sensitivity of AMACR for CIS diagnosed with IHC during clinical practice was 73% and specificity was 97%, while CK20 was 95% sensitive and 80% specific. Sensitivity of AMACR in CIS diagnosed without IHC was 100%. In all groups, AMACR had inconsistent intensity, compared to CK20 which had consistent, strong intensity. CONCLUSIONS: AMACR was usually positive in urothelial CIS and negative in non-neoplastic urothelium. However, it is important to note that AMACR was less sensitive in difficult cases, while CK20 was more sensitive with more consistent, strong staining compared to AMACR.

Netrin 1 and Alpha-Methyl Acylcoenzim-A Racemase in diagnosis of prostate cancer.

OBJECTIVES: To investigate serum and urine levels of Alpha-methylacyl-CoA-racemase (AMACR) and Netrin 1 in patients with and without prostate cancer and to determine whether these markers could be used as alternatives in diagnosis of prostate cancer instead of serum prostate specific antigen (PSA) levels. METHODS: One hundred and seventy five patients between 45-75 years to whom transrectal ultrasound guided biopsies were performed for abnormal serum PSA levels or digital rectal examinations were included. The levels of AMACR and Netrin 1 levels of blood and urine samples of 5 mL those were taken prior to biopsies were measured. . RESULTS: The mean age of the patients was 62.7 ±6.4 years. Prostate cancer was detected in 40 patients (22.8%) while 135 of them (77.2%) were diagnosed as benign prostate hyperplasia (BPH). In BPH group, serum and urine levels of AMACR and Netrin 1 were 13.4 ±16.9 ng/mL; 7.1 ±3.4 ng/mL; 164.1±46 pg/mL and 19.5 ±5.0 pg/mL respectively. The levels of serum and urine levels of AMACR and Netrin 1 were 10.2 ±9.8 ng/mL; 6.8 ±2.5 ng/mL; 159.1 ±44.1 pg/mL and 20.1 ±5.3 pg/mL respectively in prostate cancer group. There was no statistically significant difference or correlation between these two groups serum and urine AMACR and Netrin 1 results. CONCLUSIONS: Serum and urine levels of AMACR and Netrin 1 were not found to be alternatives for serum PSA levels in the diagnosis of prostate cancer in this study.

OBJETIVOS: Investigar los niveles de alfa-metil acilcoenzima-A y Netrina 1 en pacientes con y sin cáncer de próstata y determinar si estos marcadores pueden ser usados como una alternativa en el diagnóstico de cáncer de próstata en lugar del antígeno prostático específico en suero (PSA). MÉTODOS: Fueron incluidos 175 pacientes entre 45-75 años, a quienes se les realizó una biopsia de próstata guiada por ultrasonido por presentar un nivel anormal de PSA en el suero o un tacto rectal. Se tomó una muestra de 5 mL de sangre y orina para medir los niveles de alfa-metil acilcoenzima-A y Netrina 1. Estos niveles se midieron antes del análisis de la biopsia. RESULTADOS: La edad media de los pacientes fue de 62.7±6.4 años. Se detectó cander en 40 pacientes (22.8%), mientras que a 135 de ellos (77.2%) se les diagnóstico una hiperplasia benigna de próstata (HBP). En el grupo HBP los niveles en suero y orina de alfa-metil acilcoenzima-A y Netrina 1 fueron 13.4 ±16.9 ng/mL; 7.1 ±3.4 ng/mL; 164.1 ±46 pg/mL y 19.5 ±5.0 pg/mL respectivamente. En el grupo con cáncer de próstata los niveles en suero y orina de alfa-metil acilcoenzima-A y Netrina 1 fueron 10.2 ±9.8 ng/mL; 6.8 ±2.5 ng/mL; 159.1 ±44.1 pg/mL y 20.1 ±5.3 pg/mL respectivamente. No hubo una diferencia significativa o una correlación entre los niveles de alfa-metil acilcoenzima-A y Netrina 1 en suero y orina al comparar estos dos grupos de pacientes. CONCLUSIONES: Los niveles de alfa-metil acilcoenzima-A y Netrina 1 en suero y orina no son una alternativa para reemplazar el PSA en suero para el diagnóstico de cáncer de próstata.

Netrin 1 and Alpha-Methyl Acylcoenzim-A Racemase in diagnosis of prostate cancer / Netrina 1 y Alfa Metil-Acil coenzima-A Racemasa para el diagnóstico de cáncer de próstata

Abstract Objectives: To investigate serum and urine levels of Alpha-methylacyl-CoA-racemase (AMACR) and Netrin 1 in patients with and without prostate cancer and to determine whether these markers could be used as alternatives in diagnosis of prostate cancer instead of serum prostate specific antigen (PSA) levels. Methods: One hundred and seventy five patients between 45-75 years to whom transrectal ultrasound guided biopsies were performed for abnormal serum PSA levels or digital rectal examinations were included. The levels of AMACR and Netrin 1 levels of blood and urine samples of 5 mL those were taken prior to biopsies were measured. . Results: The mean age of the patients was 62.7 ±6.4 years. Prostate cancer was detected in 40 patients (22.8%) while 135 of them (77.2%) were diagnosed as benign prostate hyperplasia (BPH). In BPH group, serum and urine levels of AMACR and Netrin 1 were 13.4 ±16.9 ng/mL; 7.1 ±3.4 ng/mL; 164.1±46 pg/mL and 19.5 ±5.0 pg/mL respectively. The levels of serum and urine levels of AMACR and Netrin 1 were 10.2 ±9.8 ng/mL; 6.8 ±2.5 ng/mL; 159.1 ±44.1 pg/mL and 20.1 ±5.3 pg/mL respectively in prostate cancer group. There was no statistically significant difference or correlation between these two groups serum and urine AMACR and Netrin 1 results Conclusions: Serum and urine levels of AMACR and Netrin 1 were not found to be alternatives for serum PSA levels in the diagnosis of prostate cancer in this study.

Resumen Objetivos: Investigar los niveles de alfa-metil acilcoenzima-A y Netrina 1 en pacientes con y sin cáncer de próstata y determinar si estos marcadores pueden ser usados como una alternativa en el diagnóstico de cáncer de próstata en lugar del antígeno prostático específico en suero (PSA). Métodos: Fueron incluidos 175 pacientes entre 45-75 años, a quienes se les realizó una biopsia de próstata guiada por ultrasonido por presentar un nivel anormal de PSA en el suero o un tacto rectal. Se tomó una muestra de 5 mL de sangre y orina para medir los niveles de alfa-metil acilcoenzima-A y Netrina 1. Estos niveles se midieron antes del análisis de la biopsia. Resultados: La edad media de los pacientes fue de 62.7±6.4 años. Se detectó cander en 40 pacientes (22.8%), mientras que a 135 de ellos (77.2%) se les diagnóstico una hiperplasia benigna de próstata (HBP). En el grupo HBP los niveles en suero y orina de alfa-metil acilcoenzima-A y Netrina 1 fueron 13.4 ±16.9 ng/mL; 7.1 ±3.4 ng/mL; 164.1 ±46 pg/mL y 19.5 ±5.0 pg/mL respectivamente. En el grupo con cáncer de próstata los niveles en suero y orina de alfa-metil acilcoenzima-A y Netrina 1 fueron 10.2 ±9.8 ng/mL; 6.8 ±2.5 ng/mL; 159.1 ±44.1 pg/mL y 20.1 ±5.3 pg/mL respectivamente. No hubo una diferencia significativa o una correlación entre los niveles de alfa-metil acilcoenzima-A y Netrina 1 en suero y orina al comparar estos dos grupos de pacientes. Conclusiones: Los niveles de alfa-metil acilcoenzima-A y Netrina 1 en suero y orina no son una alternativa para reemplazar el PSA en suero para el diagnóstico de cáncer de próstata.

[Acquired cystic kidney disease-associated renal cell carcinoma: a clinicopathologic study of three cases].

Objective: To study the clinicopathologic, immunohistochemical (IHC), histogenetic and prognostic features of acquired cystic kidney disease-associated renal cell carcinoma (ACKD-RCC). Methods: Three cases of ACKD-RCC, including two from 401 Hospital of PLA and one from the Affiliated Hospital of Qingdao University were studied by clinical, histological and IHC analysis with review of relevant literature. Results: All the three patients were male, ranging from 46 to 78 years old. All patients had history of chronic renal failure; two patients were treated with hemodialysis for 9 years and 11 years, respectively. In two cases the tumor sizes were 2.5 cm and 3.5 cm, respectively, and the tumor border was distinct. The remaining case showed extensive renal hemorrhage with an inconspicuous mass. Microscopically, the tumor cells were arranged in cribriform, microcystic or acinar structures, with variable papillary structure in one case. Hemorrhage of varying degrees was seen in all three cases, and obvious necrosis was noted in two. The tumor cells had deeply eosinophilic cytoplasm, indistinct cell border, round or oval nuclei, and prominent nucleoli (WHO/ISUP grade 3). Mitoses were rare. Abundant oxalate crystals were seen in two cases. The renal mesenchyme of all three cases were atrophic with variable cystic changes of the renal tubules, the lining cells showed atypical hyperplasia. IHC staining showed all tumors were diffusely positive for vimentin, CD10, RCC, CAM5.2, P504s and mitochondria in the cytoplasm, and were variably positive for EMA (2/3), CK7 (1/3), CA9 (1/3) and PAX8 (3/3). All cases were negative for CD117, HMB45, Melan A and TFE3. After 3-14 months follow-up, one patient died from renal failure six months after surgery. The other two patients were alive without tumor recurrence or metastasis. Conclusions: ACKD-RCC is a very rare renal cell carcinoma. The specific cribriform structure, deeply eosinophilic cytoplasm, prominent nucleoli (WHO/ISUP grade 3), and oxalate crystals deposition, associated with the history of ACKD could aid the diagnosis. ACKD-RCC arises from the proximal renal tubule and its histogenesis might be associated with proliferation and malignant change of the atypical epithelial cells of the cystic renal tubules. ACKD-RCC may have a favorable prognosis except for tumors with sarcomatoid differentiation.

Prostate cancer: diagnostic criteria and role of immunohistochemistry.

The diagnosis of prostate cancer is based on microscopic criteria. Presently, prostate needle biopsy interpretation can be a challenge for the pathologist due to the increased number of specimens with limited amount of suspicious glands and minimal atypia. It is critical for the pathologist to have an organized methodical approach when considering the morphological features enabling a definitive diagnosis of prostate cancer. Although several diagnostic criteria and supportive features have been advocated, only few findings are absolutely specific and diagnostic of prostate cancer. The diagnosis of prostate cancer relies on a combination of architectural and cytological features that are reviewed in detail herein. Infiltrative growth pattern, prominent nucleoli and lack of basal cells are the most useful diagnostic criteria. Perineural invasion, glomerulation and mucinous fibroplasia are pathognomonic features of prostate cancer, although uncommon on small prostate cancer foci. The role of immunohistochemistry in establishing a diagnosis of limited prostate is addressed.

Variants of acinar adenocarcinoma of the prostate mimicking benign conditions.

Histological variants of acinar adenocarcinoma of the prostate may be of significance due to difficulty in diagnosis or due to differences in prognosis compared to usual acinar adenocarcinoma. The 2016 World Health Organization classification of acinar adenocarcinoma includes four variants that are deceptively benign in histological appearance, such that a misdiagnosis of a benign condition may be made. These four variants are atrophic pattern adenocarcinoma, pseudohyperplastic adenocarcinoma, microcystic adenocarcinoma, and foamy gland adenocarcinoma. They differ from usual small acinar adenocarcinoma in architectural glandular structure and/or cytoplasmic and nuclear alterations. The variants are often admixed, in variable proportions, with usual small acinar adenocarcinoma that is often Gleason pattern 3 but may be high-grade pattern 4 in a minority of cases. Atrophic pattern adenocarcinoma can be identified in a sporadic setting or after radiation or hormonal therapy. This variant is characterized by cytoplasmic volume loss and can resemble benign glandular atrophy, an extremely common benign process in the prostate. The glands of pseudohyperplastic adenocarcinoma simulate usual epithelial hyperplasia, with gland complexity that is not typical of small acinar adenocarcinoma. These complex growth configurations include papillary infoldings, luminal undulations, and branching. Microcystic adenocarcinoma is characterized by cystic dilation of prostatic glands to a size that is much more commonly observed in cystic change in benign prostatic glands. Finally, the cells in foamy gland adenocarcinoma display cytoplasmic vacuolization and nuclear pyknosis, features that can found in benign glands and macrophages. Three of the four variants (atrophic, pseudohyperplastic, and microcystic) are assigned low-grade Gleason pattern 3. Of significance, foamy gland adenocarcinoma can be Gleason pattern 3 but can also be high-grade pattern 4 or 5. Diagnostic awareness of the existence of these deceptively benign-appearing variants of acinar adenocarcinoma is essential so that an accurate diagnosis of prostate cancer may be rendered.

[The value of alpha-methylacyl-CoA racemase expression in the progression of colonic carcinoma]. / Valor de la expresión inmunohistoquímica de alfa-metilacil-CoA racemasa en la progresión del carcinoma de colon.

Alpha-methylacyl-CoA racemase (AMACR) expression has been demonstrated in several normal tissues and in diverse types of carcinoma. Our aim was to analyze the immunohistochemical expression of AMACR in the sequence-progression of colonic cancer. We studied 237 cases, including samples of normal mucosa of the colon, adenomas with different degrees of dysplasia, colonic carcinomas, lymph nodes and liver metastases of colonic carcinomas. A scale of intensity and percentage of expression was used to analyze the AMACR immunohistochemical profile. The expression was nearly absent in samples of normal mucosa, increased in both adenomas and carcinomas, decreased in lymph node metastases but was significantly increased in liver metastases.

A novel colorimetric assay for α-methylacyl-CoA racemase 1A (AMACR; P504S) utilizing the elimination of 2,4-dinitrophenolate.

α-Methylacyl-CoA racemase (AMACR; P504S) regulates branched-chain fatty acid degradation, activates Ibuprofen and is a recognised cancer drug target. A novel, facile colorimetric assay was developed based on elimination of 2,4-dinitrophenolate. The assay was used to test 5 known inhibitors, determining IC50 and Ki values, reversibility and characterizing irreversible inhibition.

Purification and characterization of d-allulose 3-epimerase derived from Arthrobacter globiformis M30, a GRAS microorganism.

An enzyme that catalyzes C-3 epimerization between d-fructose and d-allulose was found in Arthrobacter globiformis strain M30. Arthrobacter species have long been used in the food industry and are well-known for their high degree of safety. The enzyme was purified by ion exchange and hydrophobic interaction chromatographies and characterized as a d-allulose 3-epimerase (d-AE). The molecular weight of the purified enzyme was estimated to be 128 kDa with four identical subunits. The enzyme showed maximal activity and thermostability in the presence of Mg2+. The optimal pH and temperature for enzymatic activity were 7.0-8.0 and 70°C, respectively. The enzyme was immobilized to ion exchange resin whereupon it was stable for longer periods than the free enzyme when stored at below 10°C. In the column reaction, the enzyme activity also maintained stability for more than 4 months. Under these conditions, 215 kg of d-allulose produced per liter immobilized enzyme, and this was the highest production yield of d-allulose reported so far. These highly stable properties suggest that this enzyme represents an ideal candidate for the industrial production of d-allulose.

[Diagnostic utility of immunohistochemistry in differential diagnosis of renal tumors with oncocytic features].

Objective: To investigate the morphological features and immunophenotypes of eosinophilic renal tumors in order to provide references for the differential diagnosis of this tumor. Methods: A cohort of 75 cases of eosinophilic renal tumors were collected. The morphological features of the tumors were observed under microscope, and the immunophenotypes of the tumors were detected using tissue microarray and immunoshistochemistry. Results: There were some overlaps between the different types of eosinophilic renal tumors in morphology, but each had its distinct characteristics. Immunohistochemically, renal oncocytoma (RO) and eosinophilic chromophobe renal cell carcinoma (ChRCC) shared some common immumophenotypes, except for the expression of CK7, with the expression rates of 2/19 in RO and 17/20 in eosinophilic ChRCC, respectively. Eosinophilic clear cell renal cell carcinoma mainly showed positive immunostaining for Vimentin and CAⅨ, whereas negative for CK7 and CD117 in most cases (10/15). AMACR was diffusely expressed in the majority of eosinophilic papillary renal cell carcinoma (PRCC, 10/13). Furthermore, vimentin, CK7 and CD10 were positively expressed in eosinophilic PRCC with the expression rates of 8/13, 9/13 and 6/13, respectively; while CAⅨ, CD117 and TFE3 were all negatively expressed in eosinophilic PRCC.Epithelioid angiomyolipoma generally showed positive expression of vimentin, SMA and HMB45, but negative expression of CAⅨ and CK7. Vimentin, CD10, AMACR and TFE3 were strongly expressed in XP11.2 translocation renal cell carcinoma; on the contrary, CK7, CD117 and HMB45 were not expressed in the majority of the tumor. Conclusion: With full understanding of the morphology of different types of eosinophilic renal tumors, the immunostaining of vimentin, CAⅨ, CK7, CD10, AMACR, CD117, TFE3 and HMB45 could play a crucial role in the differential diagnosis of these tumors.

Same difference: A pilot study of cyclin D1, bcl-2, AMACR, and ALDH-1 identifies significant differences in expression between primary colon adenocarcinoma and its metastases.

Tumor heterogeneity implies the possibility of significantly different expression of key pathways between primary and metastatic clones. Colon adenocarcinoma is one of the few tumors where current practice includes resection of primary and isolated organ metastases simultaneously without neoadjuvant therapy. We performed a pilot study on 28 cases of colon adenocarcinoma resected simultaneously with metastases in patients with no history of neoadjuvant therapy. We assayed matched primary and metastatic tumors from each patient with common diagnostic antibodies to Bcl-2, Cyclin D1, AMACR, and ALDH-1 by immunohistochemistry with semi-quantitative interpretation on archived formalin fixed, paraffin embedded samples. We were powered for large, consistent differences between primary and metastatic expression, and found 21 of 28 had a significant difference in expression of at least one of the four proteins, accounting for multiplicity of testing. Cyclin D1 had significantly more cases with differential metastatic:primary expression than would be expected by chance alone (p-value 0.0043), favoring higher expression in the metastatic sample. Bcl-2 and ALDH-1 had trends in this direction (p-value 0.078 each). Proportionately more cases with significant differences were identified when a liver metastasis was tested. We conclude differences in expression between metastatic and primary colon adenocarcinoma within the same patient exist, and may have therapeutic and biomarker testing consequences.

Immunohistochemistry in the diagnosis of dysplasia in chronic inflammatory bowel disease colorectal polyps.

BACKGROUND AND STUDY AIMS: Development of cancer is the most significant complication in inflammatory bowel disease (IBD). Distinguishing true dysplasia from reactive atypia in polyps is difficult, leading sometimes to the unsatisfactory diagnosis of "indefinite for dysplasia". Therefore, there is a need for the development of markers that can help improve diagnosis. We evaluated the diagnostic value of the expression of AMACR, Ki67 and p53 by immunohistochemistry in the diagnosis of dysplasia in polyps developed on IBD. PATIENTS AND METHODS: Forty colorectal polyps in IBD were studied. These had been diagnosed over a period of 11years. Dysplasia was classified according to the Vienna Classification (version 2000). Immunohistochemistry was performed using anti-AMACR, anti-Ki67 and anti-p53 antibodies. RESULTS: Polyps were classified as follows: 21 negative for dysplasia (ND), 10 indefinite for dysplasia (IFD), 6 low-grade dysplasia (LGD), 1 high-grade dysplasia (HGD) and 2 adenocarcinomas (ACA). AMACR positivity was observed in all polyps with HGD and ACA, 5 of the 6 LGD polyps and 3 of the 10 IFD (p=0.007). p53 immunostaining showed nuclear staining in the basal part of the crypts in 8 of the 10 IFD lesions. In ACA and HGD polyps, p53 positivity was typically observed in all epithelial cell layers (p=0.004). ACA and HGD showed diffuse and scattered staining of Ki67 along the full length of the crypts. Five lesions with LGD had extension of Ki-67 positive cells up to and into the surface epithelium. Ki67 staining in all IFD lesions was restricted to the basal third of the crypt (p<0.001). By combining the three markers, a relationship with dysplasia was statistically significant (p<0.001). Sensitivity ranged from 66.7% to 88.9% and specificity from 71.4% to 100%. The positive predictive value (PPV) for detecting dysplasia using these different antibodies ranged from 66.7% to 100% and the negative predictive value (NPV) for excluding dysplasia ranged from 85.7% to 93.3%. CONCLUSIONS: The high degree of sensitivity and specificity of AMACR, p53 and Ki67 for dysplasia in IBD suggests that these antibodies, when combined, may be useful to detect neoplastic epithelium in this condition.

Significance of prostate cancer missed on needle biopsy tools for retrieving missed cancer.

BACKGROUND: Prostate needle biopsy (PNB) is required for the diagnosis of prostate cancer (PCa), but little is known about the frequency and clinical implication of false-negative results. OBJECTIVE: To investigate the incidence and clinical impact of minute PCa missed on routine haematoxylin and eosin (H&E) slides, but retrieved by α-methylacyl-CoA-racemase (AMACR) immunohistochemistry. METHODS: AMACR immunohistochemistry was used to detect PCa missed on H&E slides in a series of consecutive 1,672 PNB including 1,003 patients without evidence of PCa, and 669 patients with PCa meeting pathological criteria for active surveillance (PCAS) under current clinical investigation, including Gleason score ≤7 (3 + 4), <33% of biopsies involved by cancer, <50% of any core involved by cancer. Using improved multicore (pre-) embedding techniques a single AMACR immunostain/patient was sufficient to detect missed lesions. RESULTS: In patients without histological evidence of PCa, AMACR immunohistochemistry retrieved minute PCa in 33 of 1,003 patients (3.29%) and atypical small acinar proliferations (ASAP) in 17 of 1,003 patients (1.69%). Among 116 of 669 (17.34%) PCa patients meeting PCAS, detection of additional core(s) involved by cancer was found responsible for disease reclassification in 63 of 116 of patients (54.31%). Limitations include the single-institutional design of the study. CONCLUSIONS: PCa missed on routine H&E histology was retrieved by AMACR in 8.91% of PNB, including 17.34% of PCa patients meeting PCAS. 54.31% of them have finally lost their eligibility for active surveillance after detecting additional cores involved by cancer. Underdiagnosis of limited adenocarcinoma on PNB is a matter of concern, but can be prevented by a single AMACR immunostain/patient if improved multicore (pre-) embedding techniques are used.