CM-Path Molecular Diagnostics Forum-consensus statement on the development and implementation of molecular diagnostic tests in the United Kingdom.

BACKGROUND: Pathology has evolved from a purely morphological description of cellular alterations in disease to our current ability to interrogate tissues with multiple 'omics' technologies. By utilising these techniques and others, 'molecular diagnostics' acts as the cornerstone of precision/personalised medicine by attempting to match the underlying disease mechanisms to the most appropriate targeted therapy. METHODS: Despite the promises of molecular diagnostics, significant barriers have impeded its widespread clinical adoption. Thus, the National Cancer Research Institute (NCRI) Cellular Molecular Pathology (CM-Path) initiative convened a national Molecular Diagnostics Forum to facilitate closer collaboration between clinicians, academia, industry, regulators and other key stakeholders in an attempt to overcome these. RESULTS: We agreed on a consensus 'roadmap' that should be followed during development and implementation of new molecular diagnostic tests. We identified key barriers to efficient implementation and propose possible solutions to these. In addition, we discussed the recent reconfiguration of molecular diagnostic services in NHS England and its likely impacts. CONCLUSIONS: We anticipate that this consensus statement will provide practical advice to those involved in the development of novel molecular diagnostic tests. Although primarily focusing on test adoption within the United Kingdom, we also refer to international guidelines to maximise the applicability of our recommendations.

Targeted next generation sequencing of pancreatic solid pseudopapillary neoplasms show mutations in Wnt signaling pathway genes.

Solid pseudopapillary neoplasms of the pancreas are rare neoplasms that have been shown to harbor recurrent somatic pathogenic variants in the beta-catenin gene, CTNNB1. Here, we used targeted next generation sequencing to analyze these tumors for other associated mutations. Six cases of solid pseudopapillary neoplasms were studied. DNA extracted from formalin-fixed paraffin embedded tissue blocks was analyzed using the Ion Torrent platform, with the 50-gene Ampliseq Cancer Hotspot Panel v2 (CHPv2), with further variant validation performed by Sanger sequencing. Four tumors (67%) were confirmed to harbor mutations within CTNNB1, two with c.109T > G p.(Ser37Ala) and two with c.94G > A p.(Asp32Asn). One case showed a frameshift deletion in the Adenomatous Polyposis Coli gene, APC c.3964delG p.(Glu1322Lysfs*93) with a variant allele frequency of 42.6%. Sanger sequencing on non-tumoral tissue confirmed the variant was somatic. The patient with the APC mutation developed metastasis and died. In addition to the four cases harboring CTNNB1 variants, we found a case characterized by poor outcome, showing a rare frameshift deletion in the APC gene. Since the APC product interacts with beta-catenin, APC variants may, in addition to CTNNB1, contribute to the pathogenesis of solid pseudopapillary neoplasms via the Wnt signaling pathway.

Mesonephric adenocarcinoma of the vagina masquerading as a suburethral cyst.

Mesonephric adenocarcinoma (MA) of the vagina is an extremely rare tumour of the female genital tract. There are currently 22 reported cases in the published literature. Consequently, its pathophysiology and disease progression remain poorly understood.A 63-year-old woman presented with a history of a swelling in her vagina. Two-dimensional pelvic floor ultrasound and MRI demonstrated a multiloculated cyst with no malignant features. Initial workup provided a working diagnosis of a suburethral cyst. The diagnosis of MA was made on histology after excision of the cyst. Subsequent postoperative investigation showed no spread of the disease. The patient completed a course of prophylactic brachytherapy to prevent the possibility of any recurrence of disease. Due to its rarity, it remains difficult to diagnose MA of the vagina even on histological analysis. We would therefore recommend a low threshold to excise or perform tissue biopsy of unspecified vaginal masses.

Outcome of Appendicectomies at Surgery for Mucinous Ovarian Neoplasms: Report From A UK Center and Review of Literature.

OBJECTIVE: This study aimed to determine the frequency of malignant pathology in a macroscopically normal appendix during surgery for a borderline or malignant mucinous ovarian tumor (MOT). METHODS: Women with borderline and malignant MOT were identified from the pathology database from 2000 to 2014. Women who had a benign MOT and had an appendicectomy were excluded from the study. Data were collected from the electronic patient record and case notes. RESULTS: Of 310 women identified with MOT, 203 patients with benign MOT were excluded. Of the remaining 107 patients, 15 patients with previous appendicectomy were also excluded. The study population consisted of 92 patients. There were 57 (62%) patients with borderline MOT and 35 (38%) patients with malignant MOT. In the borderline subgroup, 40/57 (70%) patients had appendicectomy of whom 8 (20%) had macroscopically abnormal appendices. One patient had pseudomyxoma peritonei secondarily involving the appendix and 7 patients had a histologically normal appendix. Normal histology was found in all macroscopically normal appendices. In the malignant subgroup, 29/35 (83%) patients had an appendicectomy. There were 8 (27.5%) macroscopically abnormal appendices with a malignant pathology in 7 (87.5%) patients and 1 patient had a resolving appendicitis. There were 21 macroscopically normal appendices of which, serrated adenoma was found in 1 (4.8%) patient, whereas the remaining 20 (95.2%) patients had normal histology. CONCLUSIONS: In MOT, an abnormal appearing appendix should be excised. If the appendix is grossly normal, our data do not support performing an appendicectomy as part of a surgical staging procedure.

Endometriosis of Extra-Abdominal Soft Tissues: A Tertiary Center Experience.

While endometriosis, defined as the presence of endometrial tissue in extrauterine sites, is most frequently encountered within the peritoneal cavity, a small but significant proportion of cases occur at extra-abdominal soft tissue sites, particularly in relation to previous abdominal surgery. We reviewed the cases of endometriosis of soft tissue sites seen at a tertiary soft tissue center. All cases of extra-abdominal soft tissue endometriosis diagnosed at this institution over a 13-year period were reviewed, and clinical and pathologic findings were recorded. Forty-five patients had diagnoses of soft tissue endometriosis and there were 34 diagnostic biopsies and 26 surgical excision specimens. All but 1 case were abdominal wall lesions, with 1 located in the upper arm. A total of 33 patients presented with lesions in scars of previous operations (31 in Pfannenstiel incisions for Caesarean sections, presenting with a median interval of 6 years (range 1-16 years) following surgery). The lesions ranged in size from 1 to 8 cm (median 3.5 cm). One case showed decidualized stroma with trophoblast cells, while 2 had secondary adenocarcinoma arising from endometriosis. Eighteen cases were tested for ß-catenin expression immunohistochemically, of which 5 showed at least focal nuclear positivity in the surrounding fibrous tissue (although not within glands or stroma). Soft tissue endometriosis is seen most commonly in surgical scars, particularly following Caesarean sections. Spontaneous endometriosis also most commonly occurs in the abdominal wall, although can occur exceptionally at unusual sites, such as extremities. Secondary changes, including carcinomas, can arise from endometriosis. The differential diagnosis of these lesions includes fibromatosis, which may be erroneously diagnosed on small, nonrepresentative core biopsy specimens.

Gross examination and reporting of soft tissue tumours: evaluation of compliance with the UK Royal College of Pathologists soft tissue sarcoma dataset.

AIMS: Soft tissue tumours are a heterogeneous group of neoplasms that can arise at almost every anatomical site. As they often show similar clinical and radiological findings, histology is the definitive diagnostic method and it is crucial that the surgical pathology report contains accurate, useful information for management and prognostication. The soft tissue sarcoma minimum dataset produced by the Royal College of Pathologists in the UK outlines a structure for handling and reporting soft tissue tumours, including the core data required, and aiding pathologists in forming a consistent reporting approach. METHODS: We assessed the information in surgical pathology reports for soft tissue lesions at a tertiary soft tissue centre, in 1 year prior to the development of this dataset, and 1 year after its release, to audit the comparative adequacy of macroscopic and microscopic information provided, and to assess for differences in reporting since the advent of routine ancillary molecular diagnostic testing. RESULTS AND CONCLUSIONS: We found that while essential information was always included in reports, more specific details contributing to better quality reports such as more detailed macroscopic descriptions and a higher proportion of clinical summaries with radiological correlation were included in 2011 than 2006, despite increasing workload. Specimen handling, particularly of core biopsies, was also improved, reflecting the increasing need to conserve the maximum amount of patient material for molecular investigations.

The comparative utility of fluorescence in situ hybridization and reverse transcription-polymerase chain reaction in the diagnosis of alveolar rhabdomyosarcoma.

Fluorescence in situ hybridization (FISH) for FOXO1 gene rearrangement and reverse transcription-polymerase chain reaction (PCR) for PAX3/7-FOXO1 fusion transcripts have become routine ancillary tools for the diagnosis of alveolar rhabdomyosarcomas (ARMS). Here we summarize our experience of these adjunct diagnostic modalities at a tertiary center, presenting the largest comparative series of FISH and PCR for suspected or possible ARMS to date. All suspected or possible ARMS tested by FISH or PCR for FOXO1 rearrangement or PAX3/7-FOXO1 fusion transcripts over a 7-year period were included. FISH and PCR results were correlated with clinical and histologic findings. One hundred samples from 95 patients had FISH and/or PCR performed. FISH had higher rates of technical success (96.8 %) compared with PCR (88 %). Where both tests were utilized successfully, there was high concordance rate between them (94.9 %). In 24 histologic ARMS tested for FISH or PCR, 83.3 % were translocation-positive (all for PAX3-FOXO1 by PCR) and included 3 histologic solid variants. In 76 cases where ARMS was excluded, there were 3 potential false-positive cases with FISH but none with PCR. PCR had similar sensitivity (85.7 %) and better specificity (100 %) in aiding the diagnosis of ARMS, compared with FISH (85 and 95.8 %, respectively). All solid variant ARMS harbored FOXO1 gene rearrangements and PAX3-FOXO1 ARMS were detected to the exclusion of PAX7-FOXO1. In comparative analysis, both FISH and PCR are useful in aiding the diagnosis of ARMS and excluding its sarcomatous mimics. FISH is more reliable technically but has less specificity than PCR. In cases where ARMS is in the differential diagnosis, it is optimal to perform both PCR and FISH: both have similar sensitivities for detecting ARMS, but FISH may confirm or exclude cases that are technically unsuccessful with PCR, while PCR can detect specific fusion transcripts that may be useful prognostically.

Fluorescence In Situ Hybridization for MDM2 Amplification as a Routine Ancillary Diagnostic Tool for Suspected Well-Differentiated and Dedifferentiated Liposarcomas: Experience at a Tertiary Center.

Background. The assessment of MDM2 gene amplification by fluorescence in situ hybridization (FISH) has become a routine ancillary tool for diagnosing atypical lipomatous tumor (ALT)/well-differentiated liposarcoma and dedifferentiated liposarcoma (WDL/DDL) in specialist sarcoma units. We describe our experience of its utility at our tertiary institute. Methods. All routine histology samples in which MDM2 amplification was assessed with FISH over a 2-year period were included, and FISH results were correlated with clinical and histologic findings. Results. 365 samples from 347 patients had FISH for MDM2 gene amplification. 170 were positive (i.e., showed MDM2 gene amplification), 192 were negative, and 3 were technically unsatisfactory. There were 122 histologically benign cases showing a histology:FISH concordance rate of 92.6%, 142 WDL/DDL (concordance 96.5%), and 34 cases histologically equivocal for WDL (concordance 50%). Of 64 spindle cell/pleomorphic neoplasms (in which DDL was a differential diagnosis), 21.9% showed MDM2 amplification. Of the cases with discrepant histology and FISH, all but 3 had diagnoses amended following FISH results. For discrepancies of benign histology but positive FISH, lesions were on average larger, more frequently in "classical" (intra-abdominal or inguinal) sites for WDL/DDL and more frequently core biopsies. Discrepancies of malignant histology but negative FISH were smaller, less frequently in "classical" sites but again more frequently core biopsies. Conclusions. FISH has a high correlation rate with histology for cases with firm histologic diagnoses of lipoma or WDL/DDL. It is a useful ancillary diagnostic tool in histologically equivocal cases, particularly in WDL lacking significant histologic atypia or DDL without corresponding WDL component, especially in larger tumors, those from intra-abdominal or inguinal sites or core biopsies. There is a significant group of well-differentiated adipocytic neoplasms which are difficult to diagnose on morphology alone, in which FISH for MDM2 amplification is diagnostically contributory.

A Unique Case of Extraovarian Sex-Cord Stromal Fibrosarcoma, With Subsequent Relapse of Differentiated Sex-Cord Tumor.

Primary fibrosarcoma arising from ovarian sex-cord stroma is a very rare neoplasm, with only a few reports in the literature. These tumors have been reported to express inhibin which allows their distinction from fibrosarcomas of soft tissue. Here, we report a case of a fibrosarcoma arising in the broad ligament. Despite being totally separate from the ovary, the tumor was diagnosed as sex-cord stromal type on the basis of inhibin expression. Furthermore, this patient suffered a recurrence of her tumor in the pelvis, which showed both the fibrosarcomatous, as well as other sex-cord elements, confirming the sex-cord stromal differentiation of the sarcoma. To our knowledge, this is the first case of a sex-cord stromal fibrosarcoma arising from an extraovarian site. Furthermore, this is also the first case of a recurrent fibrosarcoma, which showed redifferentiation of the tumor into other sex-cord components.

Clear cell sarcoma-like tumor of the gastrointestinal tract: an evolving entity.

Clear cell sarcoma-like tumor of the gastrointestinal tract (CCSLGT) is a rare malignant neoplasm that occurs in the wall of the small bowel, stomach, or large bowel, predominantly in young adults. It is an aggressive neoplasm that frequently presents with metastatic disease and has a high mortality rate. Histologically, it is usually composed of medium-sized primitive ovoid or epithelioid cells with pale or clear cytoplasm that are arranged in sheets or in papillary or alveolar architectures. Clear cell sarcoma-like tumor of the gastrointestinal tract is positive for S100 protein, invariably negative for melanocyte-specific markers and is often also positive for neuroendocrine markers. The etiology of CCSLGT is unknown, but many studies have shown associations with EWSR1-CREB1 gene fusions and, less frequently, with EWSR1-ATF1 fusions. Here, we discuss the current status of CCSLGT, including histologic, immunophenotypic, and molecular findings.

Expression profile of mucins (MUC1, MUC2, MUC5AC, and MUC6) in ovarian mucinous tumours: changes in expression from benign to malignant tumours.

AIMS: Mucins (MUCs) constitute a family of glycoproteins expressed by epithelial cells. They show specific tissue-type expression, and are useful for differentiating between different cancers. Studies have shown changes in MUC expression with tumour progression in a variety of cancers. The aim of this study was to characterize the profile of MUC expression in benign, borderline and malignant intestinal-type ovarian mucinous tumours (OMTs). METHODS AND RESULTS: MUC1, MUC2, MUC5AC and MUC6 expression was studied by immunohistochemistry in 53 OMTs (19 malignant, 25 borderline, and nine benign). The positivity frequencies of MUC1 in benign, borderline and malignant OMTs were 22.2%, 12%, and 31.6%, respectively. For MUC2, they were 0%, 40%, and 42.1%, respectively. For MUC5AC, they were 100%, 100%, and 94.8%, respectively. For MUC6, they were 66.7%, 16%, and 26.3%, respectively. Significantly increased MUC2 expression and decreased MUC6 expression were seen in borderline and malignant OMTs, as compared with benign tumours. CONCLUSION: This is the first study to compare the expression of all four MUCs in OMT with statistical analysis. We show that MUC2 expression and MUC6 expression change with the progression of benign to borderline and malignant tumours. We suggest that these changes may contribute to malignant transformation.

Histopathological diagnostic discrepancies in soft tissue tumours referred to a specialist centre: reassessment in the era of ancillary molecular diagnosis.

Introduction. Soft tissue tumour pathology is a highly specialised area of surgical pathology, but soft tissue neoplasms can occur at virtually all sites and are therefore encountered by a wide population of surgical pathologists. Potential sarcomas require referral to specialist centres for review by pathologists who see a large number of soft tissue lesions and where appropriate ancillary investigations can be performed. We have previously assessed the types of diagnostic discrepancies between referring and final diagnosis for soft tissue lesions referred to our tertiary centre. We now reaudit this 6 years later, assessing changes in discrepancy patterns, particularly in relation to the now widespread use of ancillary molecular diagnostic techniques which were not prevalent in our original study. Materials and Methods. We compared the sarcoma unit's histopathology reports with referring reports on 348 specimens from 286 patients with suspected or proven soft tissue tumours in a one-year period. Results. Diagnostic agreement was seen in 250 cases (71.8%), with 57 (16.4%) major and 41 (11.8%) minor discrepancies. There were 23 cases of benign/malignant discrepancies (23.5% of all discrepancies). 50 ancillary molecular tests were performed, 33 for aiding diagnosis and 17 mutational analyses for gastrointestinal stromal tumour to guide therapy. Findings from ancillary techniques contributed to 3 major and 4 minor discrepancies. While the results were broadly similar to those of the previous study, there was an increase in frequency of major discrepancies. Conclusion. Six years following our previous study and notably now in an era of widespread ancillary molecular diagnosis, the overall discrepancy rate between referral and tertiary centre diagnosis remains similar, but there is an increase in frequency of major discrepancies likely to alter patient management. A possible reason for the increase in major discrepancies is the increasing lack of exposure to soft tissue cases in nonspecialist centres in a time of subspecialisation. The findings support the national guidelines in which all suspected soft tissue tumour pathology specimens should be referred to a specialist sarcoma unit.

Expression profiling and significance of VEGF-A, VEGFR2, VEGFR3 and related proteins in endometrial carcinoma.

BACKGROUND: Angiogenesis plays a key role in the progression of various tumors, including endometrial carcinomas. Several cytokines and their associated receptors are shown to be involved, particularly VEGF-A with VEGFR1, -2 and -3. METHODS: The expressions of VEGF-A, VEGFR2 and VEGFR3 were studied in by immunohistochemistry in 76 endometrial carcinoma specimens. VEGFR2 and VEGFR3 receptor expression were also studied by qRT-PCR in 17 tumors in comparison to normal endometrium. The expression profiles were correlated with tumor type, grade, stage, lymphovascular invasion, disease free survival, and the expressions of other cytokine receptors (EGFR, CXCR1 and CXCR2). RESULTS: Immunohistochemically, 63% of endometrial cancers expressed VEGF-A, 55% VEGFR2 and 26% VEGFR3. VEGFR3 was significantly correlated with tumor stage (p=0.02), with a trend towards poorer disease free survival (p=0.09). VEGF-A was significantly correlated with microvessel density (p<0.01). Using qRT-PCR, increased expression of VEGFR2 (17.2-fold) and VEGFR3 (21.9-fold) was seen in endometrial carcinomas compared with normal endometrium, with significant correlations among the expression levels of VEGFR2, VEGFR3, EGFR, CXCR1 and CXCR2. CONCLUSION: Our study suggests that evaluation of VEGFR3 expression in tumors may provide prognostic data, and help identify patients who would best benefit from anti-angiogenic therapeutic agents. This is the first report showing correlations between the expressions levels of the different receptors.

"Dominant" myelolipoma encasing adrenal cortical carcinoma: an unusual variation of myelolipoma occurring as a synchronous and predominant neoplasm.

Although myelolipomas of the adrenal glands are detected with increasing frequency with advances in imaging, the occurrence of myelolipoma with adrenal cortical carcinoma remains very rare. We present a case of combined myelolipoma with adrenal cortical carcinoma in a 47-year-old man. In previously reported cases of adrenal cortical carcinoma and myelolipoma, the latter occurred as incidental foci within or peripheral to the carcinoma, perhaps representing "myelolipomatous metaplasia" rather than true neoplasia. We describe a new finding, in which the myelolipomatous component consisted of a large mass adjacent and dominant to the carcinoma. The presence of these 2 defined and apparently independent tumors suggests, in this case, the occurrence of collision or synchronous neoplastic events, rather than of metaplasia.

Expression profile of mucins in ovarian mucinous tumors: distinguishing primary ovarian from metastatic tumors.

Ovarian mucinous tumors (OMTs) of the intestinal type share morphologic features with primary tumors of other sites, and it can often be difficult to distinguish primary ovarian from metastatic mucinous tumors. MUC1, MUC2, MUC5AC, and MUC6 expressions were studied by immunohistochemistry in 36 OMTs of intestinal type (17 malignant, 19 borderline), 18 pancreatic, 12 biliary, 15 esophageal, 9 gastric, and 7 colorectal/appendiceal adenocarcinomas. All samples were from primary sites, except for colorectal tumors which were from ovarian metastases. Borderline and malignant OMTs show similar mucin immunoprofile, being strongly and uniformly positive for MUC5AC (97.2% of cases), whereas only focally positive for MUC1 (19.4%), MUC2 (38.9%), and MUC6 (22.2%). The positive frequencies of pancreatic adenocarcinomas for MUC1, MUC2, MUC5AC, and MUC6, respectively, were 100%, 16.7%, 94.4%, and 61.1%; for biliary (cholangiocarcinomas) were 91.7%, 0%, 16.7%, and 8.3%; for esophageal carcinomas were 73.3%, 33.3%, 53.3%, and 26.7%; for gastric carcinomas were 44.4%, 44.4%, 44.4%, and 0% and for lower gastrointestinal tract cancers were 28.6%, 85.7%, 42.9%, and 0%. Our study shows that OMTs are usually MUC5AC+/MUC1-, which is different from pancreatic, biliary, esophageal, gastric, and colorectal/appendiceal carcinomas. We recommend that these mucin stains be added to the panel of immunostains to differentiate metastatic tumors to the ovary from primary OMTs.

Combined mesothelial cyst and lymphangioma of the small bowel: a distinct hybrid intra-abdominal cyst.

Intra-abdominal cysts have a variety of origins, of which lymphatic and mesothelial types are the most commonly encountered. Here we describe a combined mesothelial cyst and lymphangioma arising within the small bowel subserosa of an 80-year-old woman. This was found incidentally at laparotomy performed for an unrelated condition. To date, such a hybrid lesion has not been previously reported. The ways by which this lesion might have arisen are discussed.

Expression Profiling of Proliferation and Apoptotic Markers along the Adenoma-Carcinoma Sequence in Familial Adenomatous Polyposis Patients.

Introduction. Familial adenomatous polyposis (FAP) patients have a germline mutation in the adenomatous polyposis coli (APC) gene. The APC protein interacts with beta-catenin, resulting in the activation of the Wnt signalling pathway. This results in alterations in cell proliferation and apoptosis. We investigated the expression of beta-catenin and related proliferation and apoptotic factors in FAP patients, exploring the expression along the adenoma-carcinoma sequence. Methods. The expression of beta-catenin, p53, bcl-2, cyclin-D1, caspase-3, CD10, and Ki-67 proteins was studied by immunohistochemistry in samples of colonic nonneoplastic mucosa (n = 71), adenomas (n = 152), and adenocarcinomas (n = 19) from each of the16 FAP patients. Results. The expression of beta-catenin, caspase-3, cyclin-D1, and Ki-67 was increased in both adenomas and carcinomas in FAP patients, compared with normal mucosa. p53 and CD10 expression was only slightly increased in adenomas, but more frequently expressed in carcinomas. Bcl-2 expression was increased in adenomas, but decreased in carcinomas. Conclusion. This is the first study investigating collectively the expression of these molecules together in nonneoplastic mucosa, adenomas, and carcinomas from FAP patients. We find that beta-catenin and related proliferative and apoptotic factors (cyclin-D1, bcl-2, caspase-3, and Ki-67) are expressed early in the sequence, in adenomas. However, p53 and CD10 are often expressed later in the sequence, in carcinomas.

Angiosarcoma of the Breast with Solitary Metastasis to the Ovary during Pregnancy: An Uncommon Pattern of Metastatic Disease.

Primary de novo angiosarcoma of the breast is an uncommon, aggressive neoplasm. Here, we present a case of a young woman who initially developed primary angiosarcoma of the breast, and subsequently angiosarcoma of the ovary during pregnancy two years later. Only two confirmed primary angiosarcomas of the breast metastasizing specifically to the ovary have been described in the literature. However, all previous cases had ovarian metastases at presentation or shortly after initial diagnosis. This case is unusual as it occurred after a relatively long interval, and apparently developed during pregnancy. We discuss this rare phenomenon, as well as the possible factors contributing to the recurrence.