Inter-rater concordance of basal cell carcinoma subtypes: influences on reporting format and opportunities for further classification modifications.

Diagnosis of basal cell carcinoma (BCC) higher risk subtypes influences management strategies because of their propensity to recur locally. Subtyping is prone to inter-observer variability, and subtyping definitions are inconsistently applied. This study sought to compare the interobserver reproducibility of individual BCC subtypes using the 4th edition World Health Organization (WHO) Classification of Skin Tumours (CoST) definitions, with classification into lower and higher risk histological subtype groups. Ninety-one BCC cases were rated by seven pathologists, noting the presence of BCC subtype(s), and providing a higher or lower risk subtype grouping per case. Raters were provided with definitions as per the 4th edition WHO CoST for 10 listed BCC subtypes. Surgical specimen type was noted. Subgroup analysis was performed to exclude cases when the tumour deep front was not well visualised, or there was tangential sectioning (n = 6). Light's kappa was used to assess inter-rater reliability. From the total group (n = 91), five BCC subtypes showed a sufficient number of ratings for computing a κ statistic. From these five subtypes, superficial subtype showed substantial inter-rater agreement (κ = 0.64), and the other four subtypes showed moderate inter-rater agreement [nodular (κ = 0.45), sclerosing/morphoeic (κ = 0.45), infiltrating (κ = 0.49) and micronodular (κ = 0.57)]. Two-tiered rating into either higher or lower risk subtype showed substantial inter-rater agreement (κ = 0.72). Our results suggest a need to more precisely define BCC subtypes. We suggest reporting BCC subtype using a two-tiered risk grouping, followed by specific subtypes present. Further studies examining the inter-rater reliability of less common BCC subtypes are required.

Primary dermal melanoma: clinical behaviour, prognosis and treatment.

PURPOSE: Primary dermal melanoma (PDM) is a subtype of cutaneous melanoma, confined to the dermis, which poses a challenging clinical dilemma. It may represent a true primary melanoma or a dermal cutaneous metastasis. This study aimed to delineate the histopathological characteristics and prognosis of PDM in a large patient cohort to guide appropriate treatment strategies. METHODS: A search of the Melanoma Research Database at Melanoma Institute Australia was conducted to identify all possible PDM patients at our institution diagnosed from 1978 to 2013. Overall, melanoma-specific and disease-free survival outcomes of the PDM group were compared to those of similar cohorts of Stage I-II and Stage IV M1a melanoma patients based on propensity score matching. RESULTS: Sixty-two PDM patients were identified from the MRD with a median follow-up of 6.3 years. Five-year survival was 87.1% and overall survival was 74.2%. PDMs had a significantly improved overall survival (p = 0.0002) and melanoma-specific survival (p = 0.001) compared to Stage I-II controls, however there was no difference in disease-free survival (p = 0.08). PDMs also demonstrated improved overall survival (p < 0.0001), melanoma-specific survival (p < 0.0001) and disease-free survival (p < 0.0001) compared to Stage IV M1a controls. CONCLUSION: These findings demonstrate that PDMs have a more favorable prognosis compared to stage I-II cutaneous melanomas and suggest that these are in fact true primary lesions. This study thus provides evidence to justify a treatment approach, by way of a wide local excision and possibly sentinel lymph node biopsy, as for early stage primary cutaneous melanomas.

The prognostic significance of microsatellites in cutaneous melanoma.

Microscopic satellite metastases are an adverse prognostic feature in primary cutaneous melanoma patients. The prognostic significance of microsatellites, including their number, size and distance from the primary melanoma, using the 8th edition American Joint Committee on Cancer definition, has not previously been evaluated. This study sought to determine the prognostic significance of microsatellites in histopathologically reviewed cases. Eighty-seven cases of primary cutaneous melanoma with the presence of microsatellites documented in the original pathology report and all histopathology slides available were reviewed and the findings were correlated with clinical outcome. Matched control cases were selected for all confirmed microsatellites cases. The presence of microsatellites was confirmed in 69 cases. The microsatellite group had significantly worse prognosis, with 21% 5-year disease-free survival compared with 56% in the control group (p < 0.001). The 5-year melanoma-specific survival was 53% in the microsatellites group and 73% in the control group (p = 0.004). Increasing distance (mm) of the microsatellite from the primary melanoma was found to adversely influence disease-free survival (HR = 1.24, 95% CI: 1.13-1.36, p < 0.001), overall survival (HR = 1.26 95%CI: 1.13-1.40, p < 0.001), and melanoma-specific survival (HR = 1.27 95% CI: 1.11-1.45, p < 0.001). Number and size of microsatellites were not significant prognostic factors. The presence of microsatellites was the only factor that proved to be an independent predictor of sentinel node positivity in multivariate analysis (OR 4.64; 95% CI 1.66-12.95; p = 0.003). Microsatellites were significantly associated with more loco-regional recurrences (p < 0.001) but not distant metastases (p = 0.821). Melanomas with microsatellites as defined by the 8th edition American Joint Committee on Cancer staging system are thus aggressive tumors, associated with significantly worse disease-free survival, overall survival and melanoma-specific survival. The presence of microsatellites is also associated with sentinel node-positivity and local and in-transit recurrence. Increasing distance of the microsatellite from the primary tumor is an independent adverse prognostic factor that warrants further evaluation.

FISH analysis of selected soft tissue tumors: Diagnostic experience in a tertiary center.

AIM: Fluorescence in situ hybridization (FISH) is an important ancillary tool for the classification of bone/soft tissue (BST) tumors. The aim of this study was to evaluate the contribution of FISH to the final classification of common BST entities in the molecular pathology department of the Royal Prince Alfred Hospital (RPAH), which is one of the most important referral centers for the management of sarcomas in Australia. METHODS: All routine diagnostic FISH tests performed on BST formalin-fixed paraffin embedded (FFPE) tissue specimens at the RPAH in a 5-year period (February, 2010-November, 2015) were reviewed. FISH analyses presented in this study include commercial break-apart probes (SS18, FUS, DDIT3, FUS, USP6, PDGFB, TFE3 and ALK) and a single enumeration (MDM2) probe. RESULTS: There were 434 interpretable FISH assays on BST samples including MDM2 (n=180), SS18 (n=97), FUS (n=64), DDIT3 (n=37), USP6 (n=30), PDGFB (n=13), TFE3 (n=8) and ALK (n=5). Discrepancies between the histopathological diagnosis and the FISH results were seen in 12% of the cases. In this subset of discordant cases, FISH contributed to the re-classification of 7% of cases originally diagnosed as synovial sarcoma (SS18) and 6% of adipocytic neoplasms (MDM2) based on the presence or absence of the expected gene alteration. CONCLUSION: Our study confirms that paraffin FISH is a sensitive and specific ancillary tool in the diagnosis of BST neoplasms when used in the appropriate clinicopathological context. These findings highlight the need for further ancillary molecular tools in the diagnosis and characterization of challenging cases.

Atypical Ewing sarcoma breakpoint region 1 fluorescence in-situ hybridization signal patterns in bone and soft tissue tumours: diagnostic experience with 135 cases.

AIMS: Recurrent Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangements characterize a select group of bone and soft tissue tumours. In our routine diagnostic practice with fluorescence in-situ hybridization (FISH), we have occasionally observed EWSR1 gene rearrangements in tumours not associated classically with EWSR1 translocations. This study aimed to review our institutional experience of this phenomenon and also to highlight the occurrence of unusual EWSR1 FISH signals (i.e. 5' centromeric region or 3' telomeric region signals) that do not fulfil the published diagnostic criteria for rearrangements. METHODS AND RESULTS: Using an EWSR1 break-apart probe, we performed FISH assays on formalin-fixed paraffin-embedded tissue sections from 135 bone and soft tissue specimens as part of their routine diagnostic work-up. EWSR1 gene rearrangements were identified in 51% of cases, 56% of which also showed an abnormal FISH signal pattern (in addition to classically rearranged signals). However, atypical FISH signals were present in 45% of the non-rearranged cases. In addition, we observed tumours unrelated to those described classically as EWSR1-associated that were technically EWSR1-rearranged in 6% of cases. Borderline levels of rearrangement (affecting 10-30% of lesional cells) were present in an additional 17% of these cases. CONCLUSIONS: While our study confirmed that FISH is a sensitive and specific tool in the diagnosis of EWSR1-associated tumours, atypical FISH signals and classical rearrangement in entities other than EWSR1-associated tumours can occur. Therefore, it is essential that the FISH result not be used as an isolated test, but must be evaluated in the context of clinical features, imaging, pathological and immunohistochemical findings.

Pathology review significantly affects diagnosis and treatment of melanoma patients: an analysis of 5011 patients treated at a melanoma treatment center.

BACKGROUND: Pathologists sometimes disagree on the diagnosis of melanoma or its histopathologic staging, which may have implications for treatment and follow-up. For this reason, melanoma patients referred to Melanoma Institute Australia (MIA) for further treatment routinely have their pathology slides reviewed by MIA pathologists. This study sought to determine whether diagnosis, staging, and treatment of melanoma patients changed significantly after central pathology review. METHODS: A total of 5,011 pairs of non-MIA and MIA pathology reports on the same primary melanoma specimen were reviewed. Differences in diagnosis, American Joint Committee on Cancer (AJCC) T classification, and treatment recommendations based on the non-MIA and MIA pathology reports were determined. RESULTS: A melanoma diagnosis changed in 5.1 % of cases after review. Where both pathologists agreed on a diagnosis of melanoma, AJCC T classification changed in 22.1 % after review. After MIA review, planned surgical excision margins changed in 11.2 % of cases, and a recommendation for sentinel lymph node biopsy (SLNB) changed in 8.6 %. Non-MIA reports less frequently contained criteria to define AJCC T classification (86.6 vs. 97.6 %), select appropriate surgical excision margins (95.2 vs. 99.6 %) and make a recommendation for SLNB (94.5 vs. 99.4 %), (each p < 0.001). On multivariate analysis, partial biopsies were independently associated with more frequent changes in AJCC T classification (p < 0.001), planned surgical excision margins (p < 0.001), and SLNB recommendations (p < 0.001) on the basis of MIA pathology review. CONCLUSIONS: Diagnosis, AJCC T classification, and treatment recommendations often change after pathology review by specialist melanoma pathologists. We recommend pathology review be considered for all patients attending specialist melanoma treatment centers.

Reproducibility of AJCC staging parameters in primary cutaneous melanoma: an analysis of 4,924 cases.

BACKGROUND: Pathology reports are of critical importance for conveying information to clinicians who must make important management decisions for their patients. This study sought to assess and compare the precision, reproducibility, and completeness of external pathology reports and pathology reports generated by central review of each case in a large cohort of primary cutaneous melanoma patients. METHODS: Details of matched external pathology reports and corresponding review reports for 4,924 primary cutaneous invasive melanomas diagnosed and treated at Melanoma Institute Australia (MIA) between 2001 and 2011 were analyzed. RESULTS: Interobserver agreement was excellent for American Joint Committee on Cancer (AJCC) T staging parameters: Breslow thickness (intraclass correlation coefficient [ICC] 0.984), mitotic rate (ICC 0.833), and ulceration (kappa statistic [κ] 0.823). All three of these important pathologic variables were included in 92.4 and 66.9% of review (MIA) and external (non-MIA) pathology reports, respectively. Completeness of MIA and non-MIA pathology reports for the three essential T-staging criteria increased significantly from 87.9 to 94.6% (χ(2) = 9.1, df = 1, P = 0.003) and from 53.2 to 74.3% (χ(2) = 35.0, df = 1, P < 0.001) over the 10-year study period. The AJCC N staging parameter of microsatellites was recorded in only 43% of non-MIA reports and demonstrated moderate concordance (κ = 0.560). CONCLUSIONS: Reproducibility and completeness of pathology reports for many important histopathologic features have improved in recent years. Nevertheless, the documentation of microsatellites remained poor in external pathology reports. To enhance the usefulness of the pathology report for the provision of optimal melanoma patient care, continued efforts to encourage pathologists to document its key features appear warranted.

Recent insights into the molecular pathogenesis of mammary phyllodes tumours.

Phyllodes tumours (PTs) of the breast are true biphasic neoplasms within which interactions between the epithelium and stroma are critical for tumour development and progression. Despite numerous studies reporting the results of ancillary marker investigations in PTs, the current histological grading systems remain unreliable at predicting clinical outcome even when supplemented by these markers. As a consequence, there has been much interest in the prospect of using molecular/genetic techniques to develop a more robust "grading" system. This review focuses on recent cytogenetic and molecular studies investigating the pathogenesis of PTs and those correlating molecular findings with clinicopathological features of the tumours. Recent data highlight that intratumoural genetic heterogeneity is common in PTs and may account for the reported lack of correlation between histological grading and clinical behaviour. The entire spectrum of molecular aberrations in PTs are yet to be fully defined, however recent array-based studies using comparative genomic hybridisation have reported that copy number changes increase with the progression from benign PT to malignancy. Tumour recurrence and progression is likely to reflect the presence of under-recognised subclones. p(16INK4a) (CDKN2A) inactivation also appears to be important in PT pathogenesis. Further additional studies will be required to identify and validate new prognostic markers and therapeutic targets in order to improve the diagnosis, classification, prediction of outcome and management of patients with this rare neoplasm. Data generated from modern sequencing technologies are likely to provide new insights into the disease and assist in this endeavour.

Molecular alterations in metaplastic breast carcinoma.

Metaplastic carcinoma of the breast is a rare and heterogeneous subtype of breast carcinoma with a generally poor outcome, and few therapeutic options once disease recurs or progresses. Metaplastic carcinomas of the breast are usually of a larger size at diagnosis, with less frequent nodal metastasis compared with invasive ductal carcinoma no special type, and lack hormone and HER2 receptor expression. Recent research has revealed some potentially actionable genetic changes in a subset of these rare tumours. However, ongoing efforts to further characterise the genetic basis and the molecular alterations underlying the distinctive morphological and clinical characteristics of these tumours are needed in order to identify new targets for treatment. This review will describe the theories of pathogenesis of metaplastic breast carcinoma, and highlight genetic changes and potential therapeutic targets in this generally poor prognosis malignancy.

Digital papillary adenocarcinoma: a tumour that should be considered in the differential diagnosis of neoplasms involving the digits.

BACKGROUND: Digital papillary adenocarcinoma (DPA) is a rare malignant adnexal tumour that occurs almost exclusively in a digital location. Only two case series have been reported previously. AIMS: To document the clinical and histopathological findings in a series of patients with DPA. RESULTS: Of the 8 patients identified, six were males and two were females, and they were aged between 32 and 76 years at diagnosis. The diagnosis was not clinically suspected in any of the patients, and the tumours were thought to be cysts in four cases. The tumours ranged from 7 mm to 40 mm in size, and were located on the right thumb (n=3), the right middle finger (n = 3) and the left index finger (n = 2). Each tumour exhibited a multinodular growth pattern, with a combination of solid and cystic architecture. Papillary projections were present in many of the cystic spaces. In three cases, some cystic spaces were lined by luminal columnar epithelial cells and underlying myoepithelial cells. Cytological atypia was generally mild and mitotic activity was low in most cases (median 2 mitoses per mm). Local tumour recurrence occurred in three patients, of whom one subsequently had a digital amputation. No metastases have been identified in the seven patients with known follow-up information. CONCLUSIONS: DPA is a rare tumour that should be included in the differential diagnosis of epithelial neoplasms in digital locations. Because of its tendency to recur locally, wide local excision should be performed as definitive initial treatment.

E-cadherin expression in the epithelial components of mammary phyllodes tumors.

Phyllodes tumors are rare but clinically important fibroepithelial tumors of the breast. Both epithelial and stromal components actively interact with each other to participate in phyllodes tumor development. Accumulated evidence suggests that the Wnt signaling pathway is important in this stromal-epithelial interaction. Given that Wnt signaling also affects E-cadherin-dependent cellular adhesion and alteration of E-cadherin is common in epithelial cancers, it is possible that alteration of E-cadherin occurs also in the epithelial components of phyllodes tumor. We assessed epithelial E-cadherin expression in 155 phyllodes tumor cases, including 92 benign (59%), 42 borderline (27%), and 21 malignant phyllodes tumor (14%), by immunohistochemistry. Its expression was correlated with clinicopathologic features and phyllodes tumor recurrence. Significant correlations of both membranous and cytoplasmic E-cadherin expression were found with stromal cellularity (P = .009 and .013, respectively), overgrowth (P = .005 and .009, respectively), and mitotic counts (P = .023 and .029, respectively) but not tumor grade, margin, and nuclear atypia. Interestingly, a significantly higher level of cytoplasmic epithelial E-cadherin expression was found in those tumors with recurrence (score, 278.79±40.91 versus 250.00±63.46) and shorter specific disease-free survival (172.24±12.63 versus 207.24±19.71 months). Further multivariate analysis showed epithelial E-cadherin expression as an independent prognostic factor for phyllodes tumor-specific survival (P<.001 for cytoplasmic staining and .001 for membranous staining). In conclusion, we have demonstrated an association of epithelial E-cadherin expression with stromal histologic features and disease recurrence in phyllodes tumor. These findings provide further evidence of the importance of stromal-epithelial interactions in phyllodes tumors and highlight the potential value of epithelial components in prognostication.

Involvement of α- and ß-catenins and E-cadherin in the development of mammary phyllodes tumours.

AIMS: Phyllodes tumours (PT) are rare but clinically important fibroepithelial tumours of the breast. ß-Catenin, a key component in Wnt signalling, has been shown to be important in the development of PT. It also functions as a component of the cadherin complex, which may therefore be implicated in PT pathogenesis. By assessing stromal α-catenin, ß-catenin and E-cadherin expression in 158 PT cases using immunohistochemistry and examining associations with clinicopathological features, we aimed to determine the role of these proteins in PT pathogenesis. METHODS AND RESULTS: Cytoplasmic ß-catenin correlated with α-catenin expression. A significantly higher expression of both markers was observed in borderline than in benign PT (P = 0.003 and <0.001, respectively), but a lower level was found in malignant PT. Cytoplasmic E-cadherin expression was significantly higher in borderline and malignant than in benign PT (P = 0.001 and 0.012, respectively), but was not correlated with other markers. Both E-cadherin and α-catenin showed stronger correlations with histological parameters than ß-catenin. α-Catenin showed a significant correlation with recurrence (P = 0.005 and 0.016, respectively). CONCLUSION: α- and ß-catenins may be important in the early stages of PT development, while E-cadherin may be required for malignant development. The correlation of α-catenin expression with tumour recurrence may be relevant in predicting PT behaviour.

Quality of histopathological reporting on melanoma and influence of use of a synoptic template.

AIMS: To evaluate the quality of histopathological reporting for melanoma in a whole population, to assess the influence on quality of the use of a synoptic template and thus to provide an evidence base to guide improvement in reporting melanoma pathology. METHODS AND RESULTS: Histopathology reports of all primary invasive melanomas notified to the New South Wales Central Cancer Registry between October 2006 and October 2007 (n = 3784) were reviewed. A detailed audit of histopathology reports for consecutively diagnosed primary invasive melanoma over 6 months (n = 2082) was performed to assess the quality of each report based on compliance with the 2008 Clinical Practice Guidelines for the Management of Melanoma in Australia and New Zealand. Only half of the initial excision specimen reports included the essential components necessary to stage a melanoma patient according to the 2002 American Joint Committee on Cancer/International Union Against Cancer melanoma staging system. Report format was strongly correlated with completeness and validity of reporting: reports in a synoptic format, with or without a descriptive component, achieved the highest quality levels. CONCLUSIONS: Even in a population with a high incidence of melanoma, concordance of pathology reports with current guidelines was comparatively low. Wider adoption of synoptic reporting is likely to increase report quality.

DNA methylation profiling of phyllodes and fibroadenoma tumours of the breast.

Phyllodes tumours and cellular fibroadenomas are both fibroepithelial tumours of the breast. Phyllodes tumours, unlike fibroadenomas, have the ability to recur and metastasise. Although these lesions can be distinguished by their stromal cellularity, mitotic index, presence or absence of stromal overgrowth and cellular atypia, there is overlap and not infrequently a definitive diagnosis cannot be made, particularly on biopsy. We sought to evaluate whether DNA promoter methylation profiling using selected genes known to be methylated in cancer would allow us to learn more about the biology of these tumours, and whether it could identify methylation markers that could differentiate phyllodes tumours from fibroadenomas and/or distinguish phyllodes tumours of different grades. Methylation-sensitive high resolution melting (MS-HRM) was used to screen promoter DNA methylation changes in 86 phyllodes tumours (15 benign, 28 borderline, 43 malignant) and 26 fibroadenomas. A panel of 11 genes (RASSF1A, TWIST1, APC, WIF1, MGMT, MAL, RARß, CDKN2A, CDH1, TP73 and MLH1) was tested. Methylation status was correlated with histology and with clinicopathological parameters. Five of the gene promoters showed some methylation in a proportion of phyllodes tumours; RASSF1A, 45.3%; TWIST1, 10.7%; APC, 4.1%; WIF1, 2.9% and MGMT, 1.3%. Only two genes showed any methylation in fibroadenomas usually at background levels; RASSF1A, 53.8% and MGMT, 8.3%. No CDKN2A methylation was observed in either tumour type, contrary to previous reports. Overall, the methylation patterns differed little from that which might be seen in normal cells. However, significant levels of methylation of RASSF1A (24.4%) and TWIST1 (7.1%) was observed in some phyllodes tumours. Elevated RASSF1A and/or TWIST1 methylation was significantly associated with phyllodes tumours compared with fibroadenomas (P = 0.02), TWIST1 methylation correlated with increasing malignancy in phyllodes tumours (P < 0.001). In conclusion, assessment of methylation of RASSF1A and TWIST1 may aid in the diagnosis of phyllodes tumours. The absence of frequent methylation in fibroadenomas supports a non-neoplastic origin.

p16 and pRb immunohistochemical expression increases with increasing tumour grade in mammary phyllodes tumours.

AIMS: Control of cell cycling and proliferation is critical to the development of neoplasia and may play a role in the pathogenesis of phyllodes tumours (PTs). This study aimed to evaluate the immunohistochemical expression of certain proteins from the G(1)/S transition of the cell cycle in a cohort of PTs, to determine their role in tumour pathogenesis and to identify any associations with patient outcome. METHODS AND RESULTS: Sixty-five PTs (34 benign, 23 borderline and eight malignant) diagnosed at a single institution between 1990 and 2006 were analysed. Immunohistochemistry for p16, pRb, cyclin D1 and Ki67 was performed. Expression of the following markers increased significantly with tumour grade: stromal nuclear and cytoplasmic p16 (P = 0.01 and 0.002, respectively), stromal and epithelial pRb (P = 0.000,000,06 and 0.004, respectively), and stromal and epithelial Ki67 (P = 0.03 and 0.04, respectively). Epithelial pRb scores of 7 (range 0-7) were significantly associated with reduced disease-free survival (DFS) compared with scores of <7 (P = 0.0009). No relationship was found between cyclin D1 expression in either the epithelium or the stroma, and grade or DFS. CONCLUSIONS: The results suggest that alterations at the G(1)/S transition of the cell cycle play an important role in the progression of PTs.

Reduced p16 and increased cyclin D1 and pRb expression are correlated with progression in cutaneous melanocytic tumors.

The immunohistochemical expression of cell cycle proteins p16, cyclin D1, and pRb was assessed in 112 benign and malignant melanocytic tumors and correlated with tumor progression, prognosis, and outcome. Comparing benign and malignant tumors, there were significant differences in the median score for all 3 proteins, with decreased p16 (P = .000001), increased cyclin D1 (P = .01), and increased pRb in melanomas (P = .01). There was a progressive loss of expression of p16 with progression from benign naevi to primary melanomas and to metastases. p16 was significantly decreased in primary tumors from melanoma patients who developed recurrent disease (P = .0000013). Cyclin D1 and pRb showed a progressive increase in expression from benign to malignant tumors but with relative decreases in the more advanced tumors (thick primaries and metastatic melanomas). Alterations in cell cycle proteins involved in G1/S transition are implicated in melanocytic tumor progression and have a potential role in diagnosis and prognostication.

Interobserver reproducibility of histologic parameters of melanoma deposits in sentinel lymph nodes: implications for management of patients with melanoma.

BACKGROUND: : Histologic parameters of melanoma deposits in sentinel lymph nodes (SLNs) have been shown to be predictive of clinical outcome and the presence or absence of tumor in non-SLNs, but assessment of these parameters is prone to interobserver variation. METHODS: : Histologic sections of 44 SLNs containing metastatic melanoma were examined by 7 pathologists. Parameters assessed included cross-sectional area of tumor deposits, cross-sectional area of SLNs, percentage of SLN area involved by tumor calculated from the 2 previous parameters, estimated percentage of SLN area involved by tumor, tumor penetrative depth, location of tumor within the SLN, and presence of extracapsular spread. Levels of interobserver agreement were measured by using intraclass correlation coefficients (ICC). RESULTS: : There was good to excellent interobserver agreement on measurement of quantitative parameters: maximal size of largest tumor deposits, calculated area of 3 largest tumor deposits, percentage of the area of SLN involved by tumor, and tumor penetrative depth (ICC, 0.88, 0.73, 0.68, and 0.83, respectively). There was moderate agreement on the evaluation of subcapsular versus nonsubcapsular location of tumor deposits (ICC = 0.50). Agreement on assessment of extracapsular spread was fair (ICC = 0.39). CONCLUSIONS: : Assessment of some of the quantitative parameters was highly reproducible between pathologists. However, evaluation of the location of tumor deposits within SLNs and assessment of extracapsular spread was less reproducible. Clearer definitions and training can be expected to improve the reproducibility of assessment. These results have important implications for reliability and reproducibility of these parameters in staging, prediction of outcome, and clinical management of melanoma patients. Cancer 2009. (c) 2009 American Cancer Society.

The role of intra-operative pathological evaluation in the management of musculoskeletal tumours.

A tissue biopsy is usually a critical aspect in guiding appropriate initial management in patients with musculoskeletal tumours. We have previously outlined the role of intra-operative frozen section in both the determination of adequacy of a biopsy and for its diagnostic utility. In this article, the options and techniques for intra-operative pathological evaluation, namely frozen section, fine needle aspiration cytology and touch imprint cytology are reviewed. Frozen section examination may be applicable in the following Sections, including (1) at core biopsy, (2) at surgical margins, (3) at confirming diagnosis prior to definitive treatment or to evaluate tumour spread, and (4) at establishing a diagnosis of a metastasis prior to intramedullary nailing. There are also situations in which frozen section is inappropriate. Pitfalls associated with frozen sections are also highlighted. There are also cost implications, which we have quantified, of performing frozen sections. In our experience that the use of intra-operative pathological evaluation reduces the non-diagnostic rate of bone and soft tissue sarcoma biopsies, eliminates the need for re-biopsy hence alleviating stress, and is a useful addition to the armamentarium in evaluating musculoskeletal tumours.