Gleason grading: past, present and future

In 1966 Donald Gleason developed his grading and scoring system for prostatic adenocarcinoma. This classification was refined in 1974 and gained almost universal acceptance, being classified as a category 1 prognostic parameter by the College of American Pathologists. Modifications to the classification were recommended at a conference convened by the International Society of Urological Pathology (ISUP) in 2005. This modified classification has resulted in a significant upgrading of tumours, although some studies have shown a greater concordance between needle biopsy and radical prostatectomy scores when compared to classical Gleason (CG) grading. The ISUP consensus conference recommended that for needle biopsies higher tertiary patterns should be incorporated into the final Gleason score, and this has been correlated with biochemical failure, tumour volume and mortality. Recently the validity of including cribriform glands as a component of Gleason pattern 3 has been questioned and it has been recommended that all tumours showing cribriform architecture should be classified as Gleason pattern 4. The recommendations arising from the 2005 Consensus Conference were largely unsupported by validating data, yet this new grading system has achieved widespread usage. It is unfortunate that recent suggestions for further modification are similarly lacking in supporting evidence. In view of this it is recommended that the Modified Gleason Scoring Classification should continue to be utilized in its original (2005) format and that any future alterations should be implemented only when mandated by tumour-related outcome studies.

A model to predict prostate cancer after atypical findings in initial prostate needle biopsy

PURPOSE

Atypical small acinar proliferation can occur alone or with high grade prostatic intraepithelial neoplasia in either a discontinuous or contiguous pattern in a prostate needle biopsy. We assessed whether different subgroups of atypical small acinar proliferation and high grade prostatic intraepithelial neoplasia denote a differing risk of detecting subsequent prostate cancer.

MATERIALS AND METHODS

We reviewed the pathological findings in 12,304 men who underwent initial prostatic needle biopsy during May 1999 to June 2007. Patients were included in the study if the initial diagnosis was atypical small acinar proliferation alone or combined with high grade prostatic intraepithelial neoplasia, or a benign diagnosis, and if followup prostatic needle biopsy was done.

RESULTS

Prostate cancer developed in 22%, 27% and 49% of patients in the benign, high grade prostatic intraepithelial neoplasia and atypical small acinar proliferation groups, respectively (p <0.0005). In all subgroups there was a 35% to 57% rate of prostate cancer detection. The prostate cancer risk increased in the atypical small acinar proliferation subgroups according to the extent of high grade prostatic intraepithelial neoplasia in the initial sample, with atypical small acinar proliferation associated with multifocal high grade prostatic intraepithelial neoplasia carrying a 71% prostate cancer risk.

CONCLUSIONS

Atypical small acinar proliferation combined with high grade prostatic intraepithelial neoplasia, particularly when associated with multifocal high grade prostatic intraepithelial neoplasia, is associated with a significant risk of prostate cancer detection on followup biopsy.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 5: surgical margins

The 2009 International Society of Urological Pathology Consensus Conference in Boston, made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to surgical margin assessment were coordinated by working group 5. Pathologists agreed that tumor extending close to the 'capsular' margin, yet not to it, should be reported as a negative margin, and that locations of positive margins should be indicated as either posterior, posterolateral, lateral, anterior at the prostatic apex, mid-prostate or base. Other items of consensus included specifying the extent of any positive margin as millimeters of involvement; tumor in skeletal muscle at the apical perpendicular margin section, in the absence of accompanying benign glands, to be considered organ confined; and that proximal and distal margins be uniformly referred to as bladder neck and prostatic apex, respectively. Grading of tumor at positive margins was to be left to the discretion of the reporting pathologists. There was no consensus as to how the surgical margin should be regarded when tumor is present at the inked edge of the tissue, in the absence of transected benign glands at the apical margin. Pathologists also did not achieve agreement on the reporting approach to benign prostatic glands at an inked surgical margin in which no carcinoma is present.

International Society of Urological Pathology (ISUP) consensus conference on handling and staging of radical prostatectomy specimens: rationale and organization

The 2009 International Society of Urological Pathology consensus conference in Boston, made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. The activities of the conference were coordinated through five workgroups. The results are presented in five separate reports covering (1) specimen handling, (2) T2 substaging and prostate cancer volume, (3) extraprostatic extension, lymphovascular invasion and locally advanced disease, (4) seminal vesicles and lymph node metastases and (5) surgical margins. In this introductory article we describe some novel features of the organization of the consensus process. Following the completion of a pre-meeting survey conference, participants discussed and voted on 43 specific issues of contention relating to the pathological reporting of radical prostatectomy specimens. Consensus, defined as agreement by at least 65% of participants present, was achieved for 30 questions.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 4: seminal vesicles and lymph nodes

The 2009 International Society of Urological Pathology Consensus Conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the infiltration of tumor into the seminal vesicles and regional lymph nodes were coordinated by working group 4. There was a consensus that complete blocking of the seminal vesicles was not necessary, although sampling of the junction of the seminal vesicles and prostate was mandatory. There was consensus that sampling of the vas deferens margins was not obligatory. There was also consensus that muscular wall invasion of the extraprostatic seminal vesicle only should be regarded as seminal vesicle invasion. Categorization into types of seminal vesicle spread was agreed by consensus to be not necessary. For examination of lymph nodes, there was consensus that special techniques such as frozen sectioning were of use only in high-risk cases. There was no consensus on the optimal sampling method for pelvic lymph node dissection specimens, although there was consensus that all lymph nodes should be completely blocked as a minimum. There was also a consensus that a count of the number of lymph nodes harvested should be attempted. In view of recent evidence, there was consensus that the diameter of the largest lymph node metastasis should be measured. These consensus decisions will hopefully clarify the difficult areas of pathological assessment in radical prostatectomy evaluation and improve the concordance of research series to allow more accurate assessment of patient prognosis.

A rare case of carcinoma cuniculatum of the penis in a 55-year-old

Carcinoma cuniculatum of the penis is an extremely rare variant of squamous cell carcinoma characterized by an endophytic deeply branching and burrowing growth pattern. One documented case series demonstrated afflicted patients ranging in age from 73-83 years with the tumour located on the glans penis, coronal sulcus or foreskin. We report a case of a 55-year-old with disease located on the ventral aspect of the shaft of the penis. The tumour was invasive into the deep dermal connective tissue, comparatively superficial to all previous documented cases. He subsequently underwent a partial penectomy. The case is discussed with a brief review of the literature.

Is high grade prostatic intraepithelial neoplasia still a risk factor for adenocarcinoma in the era of extended biopsy sampling?

AIMS

There is controversy regarding the role of high grade prostatic intraepithelial neoplasia (HGPIN) on prostatic needle biopsy (PNB) as a risk factor for prostatic adenocarcinoma. We utilise a large Canadian database to determine whether HGPIN detected on extended PNB is a significant risk factor for prostatic adenocarcinoma.

METHODS

Pathological findings from PNBs from 12 304 men who underwent initial PNB during an 8 year period were analysed. Patients were included in the study if their initial diagnosis was HGPIN alone or a benign diagnosis, if at least one follow-up PNB was performed, and if both the initial and follow-up PNB contained at least 10 prostate cores.

RESULTS

In the benign group of 105 patients and the HGPIN group of 120 patients, 14.1% and 20.8% were diagnosed with prostatic adenocarcinoma, respectively. When the HGPIN group was further subdivided into unifocal (1 core) and multifocal (>or=2 cores) groups, 9.4% and 29.9% developed prostatic adenocarcinoma, respectively (p < 0.0001). Cox regression analysis adjusting for age and prostate specific antigen (PSA) confirms the significance of HGPIN as a risk factor for prostatic adenocarcinoma (p = 0.0045).

CONCLUSIONS

Patients with an initial diagnosis of multifocal HGPIN on extended PNB are at a greater risk for subsequent prostatic adenocarcinoma than those with unifocal HGPIN or benign diagnoses.

Type 2 and clear cell papillary renal cell carcinoma, and tubulocystic carcinoma: a unifying concept

The clinical and pathological features of multiple different renal neoplasms arising in a setting of end-stage renal disease in a 72-year-old male are described. The kidney showed features of renal oncocytosis with multiple oncocytomas, hybrid tumours and chromophobe renal carcinoma. In addition, the kidney contained a type 2 papillary renal cell carcinoma, clear cell papillary and cystic renal cell carcinoma, and tubulocystic carcinoma. The occurrence of these three tumours in a setting of end-stage kidney disease is unique and suggests a common pathogenesis. Immunostaining of these tumours further suggests they are derived from similar stem cells which show immunophenotypic features of both the proximal and distal nephron.

Solitary Intestinal Fibromatosis with Perinatal Bowel Obstruction

Three newborn male infants presented with bowel obstruction in the first day of life and at surgery were found to have solitary tumors involving the small or large intestine. Histologic examination in each case showed a transmural infiltrative spindle cell lesion having the morphologic features of fibromatosis. Ultrastructural studies in one case revealed the tumor to be composed of myofibroblasts. The patients are all alive and well without recurrences 26 months to 10 years after surgery. Only 3 previous cases of solitary congenital fibromatosis of the intestinal tract have been reported. Some of the other congenital spindle cell tumors cited in the literature under various names have morphologic and biologic similarities to our cases and may in fact be examples of congenital fibromatosis. The appropriate treatment of this unusual lesion is local excision, and the prognosis is excellent.

Standardized synoptic cancer pathology reporting: a population-based approach

Cancer pathology reports contain information which is critical for patient management and for cancer surveillance, resource planning, and quality purposes. The College of American Pathologists (CAP) has defined scientifically validated content of checklists that form the basis for synoptic cancer pathology reporting. We outline how the CAP standards were implemented in a large Canadian province over a 3-year period resulting in improvements in rates of synoptic reporting and completeness of cancer pathology reporting.

Uncommon and recently described renal carcinomas

Major consensus conferences held over a decade ago laid the foundations for the current (2004) WHO classification of renal carcinoma. Clear cell, papillary and chromophobe carcinomas account for 85-90% carcinomas seen in routine practice. The remaining 10-15% of carcinomas consist of rare sporadic and hereditary tumors, some of which had been long recognized, but many of which only emerged as distinct entities in the decade leading up to the WHO publication. Collecting-duct carcinoma is a rare, often lethal form of carcinoma. Medullary carcinoma associated with sickle cell trait, has emerged as a distinctive tumor showing some overlapping features with upper tract urothelial carcinoma. Mucinous tubular and spindle-cell carcinoma and tubulocystic carcinoma were earlier considered as patterns of low-grade collecting-duct carcinoma, but are now recognized as separate tumor entities. Carcinomas associated with somatic translocations of TFE3 and TFEB comprise a significant proportion of pediatric renal carcinomas. Oncocytoid renal carcinomas in neuroblastoma survivors was recognized as a unique tumor category in the WHO classification. Renal carcinoma associated with end-stage renal disease is now recognized as having distinct morphological patterns and behavior. In addition there is a group of rare recently described carcinomas, including clear cell papillary carcinoma, oncocytic papillary renal cell carcinoma, follicular renal carcinoma and leiomyomatous renal cell carcinoma. It behooves the surgical pathologist to not only be capable of diagnosing the common forms of renal cancer, but also to be aware of the rare types of renal carcinoma, many of which have emerged in recent years.

Rectal gastrointestinal stromal tumor mimicking a primary prostatic lesion

The interstitial cells of Cajal have been identified in locations beyond the gastrointestinal tract, including the prostate, uterus and bladder. Indeed, there are reports of primary gastrointestinal stromal tumor (GIST) arising from each of these sites. We report the case of a 72-year old male who presented with benign prostatic hypertrophy and was diagnosed on retropubic prostatectomy as having a GIST. While the initial clinical and radiologic impression was that of a primary prostatic GIST, subsequent imaging ultimately revealed a small rectal extension as the source of the lesion. The purpose of our report is to highlight the need to assiduously rule-out gastrointestinal sources of GIST prior to making the diagnosis of primary prostatic GIST.

Expression analysis of kidney-specific cadherin in a wide spectrum of traditional and newly recognized renal epithelial neoplasms: diagnostic and histogenetic implications

Kidney-specific cadherin (Ksp-cad) is a membrane-associated cell adhesion glycoprotein expressed by the distal nephron tubular cells in its later developmental stages. Chromophobe renal cell carcinoma and renal oncocytoma are reported to be variably positive for Ksp-cad with some studies suggesting a discriminatory role for Ksp-cad. Immunoreactivity in other tumors with granular eosinophilic cytoplasm including clear cell and papillary renal cell carcinomas needs to be clearly elucidated and its expression in emerging novel and other unusual renal epithelial neoplasm subtypes including tumors with uncertain histogenesis is not yet known. In this study, we performed a detailed immunohistochemical analysis for Ksp-cad in a broad range of 136 renal epithelial neoplasms. Reactivity with Ksp-cad was observed in the following tumors: chromophobe renal cell carcinoma [23/25 (92%), diffuse (>50% of tumor cells)] positivity and membranous characteristically accentuating the "plant cell-like" histomorphology of the typical (clear) type, renal oncocytoma [15/20 (75%), usually diffuse staining with predominantly membranous accentuation], papillary renal cell carcinoma [5/17 (29%) all focal to moderate, eosinophilic type or type 2-3/7 (43%), basophilic type or type 1-2/10 (20%)], Xp11 translocation carcinoma [1/4 (25%), diffuse positivity] and clear cell renal cell carcinoma [6/36 (17%) all focal, clear cell renal cell carcinoma with prominent eosinophilic cells 1/7 (14%)]. Immunoreactivity was higher when evaluating whole histologic sections than with tissue microarrays for both chromophobe renal cell carcinoma (100% vs. 60%) and renal oncocytoma (100% vs. 55%). No immunoreactivity was observed in mucinous tubular and spindle cell carcinomas (0/23), high-grade collecting duct carcinomas (of Bellini) (0/3), renal medullary carcinomas (0/2), and urothelial carcinomas (0/6). Our study documents the immunoreactivity of Ksp-cad in the range of contemporarily classified renal epithelial neoplasms. The findings argue against the use of Ksp-cad in differentiating chromophobe renal cell carcinoma and renal oncocytomas and further support their relationship to the distal nephron. Ksp-cad may be helpful in distinguishing these two tumor types from clear cell renal cell carcinoma with prominent eosinophilic cells particularly in cases with limited tissue samples (ie, needle core biopsy). In the similar diagnostic setting, caution must be exercised, however, in differentiating chromophobe renal cell carcinoma and renal oncocytoma from the eosinophilic variant of papillary renal cell carcinoma as moderate expression of Ksp-cad may be observed in papillary renal cell carcinoma. The histogenesis of mucinous tubular and spindle cell carcinoma remains debatable as this tumor does not express Ksp-cad, which is highly expressed normally in the thick ascending loop of Henle and the distal convoluted tubules. In conclusion, Ksp-cad is a useful tumor type associated marker for distinguishing chromophobe renal cell carcinoma and renal oncocytoma from the wide range of nonintercalated cell-related adult renal epithelial neoplasms; addition of this marker to a panel comprised of other histologic subtype-associated markers may greatly facilitate histologic subclassification of adult renal epithelial neoplasms.