A pilot study to explore circulating tumour cells in pancreatic cancer as a novel biomarker.

BACKGROUND: Obtaining tissue for pancreatic carcinoma diagnosis and biomarker assessment to aid drug development is challenging. Circulating tumour cells (CTCs) may represent a potential biomarker to address these unmet needs. We compared prospectively the utility of two platforms for CTC enumeration and characterisation in pancreatic cancer patients in a pilot exploratory study. PATIENTS AND METHODS: Blood samples were obtained prospectively from 54 consenting patients and analysed by CellSearch and isolation by size of epithelial tumour cells (ISET). CellSearch exploits immunomagnetic capture of CTCs-expressing epithelial markers, whereas ISET is a marker independent, blood filtration device. Circulating tumour cell expression of epithelial and mesenchymal markers was assessed to explore any discrepancy in CTC number between the two platforms. RESULTS: ISET detected CTCs in more patients than CellSearch (93% vs 40%) and in higher numbers (median CTCs/7.5 ml, 9 (range 0-240) vs 0 (range 0-144)). Heterogeneity observed for epithelial cell adhesion molecule, pan-cytokeratin (CK), E-Cadherin, Vimentin and CK 7 expression in CTCs may account for discrepancy in CTC number between platforms. CONCLUSION: ISET detects more CTCs than CellSearch and offers flexible CTC characterisation with potential to investigate CTC biology and develop biomarkers for pancreatic cancer patient management.

Follicular dendritic cell sarcoma: a rare tumor presenting as an abdominal mass.

Follicular dendritic cell (FDC) sarcoma is a rare and probably even underreported entity. Only approximately some 50 cases have been described in the literature, the majority of which had a lymph node origin. The authors report a case of FDC sarcoma arising within the soft tissues of the abdominal cavity. As FDC markers are often not routinely included in antibody panels, awareness of this sarcoma is important, as it can be confused with other tumors, especially when occurring extranodally.

Active CMV disease does not always correlate with viral load detection.

The use of quantitative cytomegalovirus (CMV) real-time polymerase chain reaction (RT-PCR) and preemptive ganciclovir therapy is replacing prophylaxis as the management of choice in high-risk patients undergoing stem cell transplantation (SCT). However, there are limited data defining its role in this setting. In the current retrospective single-centre study, quantitative RT-PCR was used to determine CMV in 577 consecutive patients undergoing SCT (172 allogeneic and 405 autologous) over a 5-year period. CMV RT-PCR was performed weekly until cessation of immunosuppression (allogeneic) or for 30 days post-SCT (autologous). Treatment was commenced after two consecutive positive results or a high copy on the first occasion (> 1000 copies/ml, > 3 log). The overall CMV reactivation rate in patients undergoing allogeneic SCT was 30%, with reactivation observed in 72% of high-risk patients (recipient positive patients). CMV end-organ disease was observed in eight patients (1%); of these, four were CMV RT-PCR negative at the time of diagnosis of end-organ CMV disease, with three remaining negative throughout the course of the disease. CMV-related mortality was recorded in three patients. The current data support a preemptive treatment strategy-based CMV RT-PCR, but indicate that in symptomatic patients, a negative CMV PCR result does not exclude CMV end-organ disease.

Pseudomyxoma peritonei: unusual origin from an ovarian mature cystic teratoma.

Pseudomyxoma peritonei (PMP) is classified into pathologically and prognostically distinct categories, such as disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis. There is overwhelming evidence that DPAM arises from a mucinous adenoma of the appendix. The one exception to this is the presentation of a mature ovarian cystic teratoma as PMP where the appendix is normal. This report describes such a case and discusses the presentation, histopathology, and treatment options.

Regressed cutaneous malignant melanoma mimicking lymphoma: a potential diagnostic pitfall.

We report 2 cases of partially regressed malignant melanoma in which the brisk lymphocytic response closely resembled mycosis fungoides in 1 case and nodular sclerosing Hodgkin lymphoma in the other. Striking epidermotropism was present in both cases. The lymphocytes were predominantly of T8 cytotoxic subtype, and oligoclonal T-cell expansion was detected in 1 of the cases. The scanty residual melanoma cells were highlighted with HMB45 and S100 protein. We highlight the features of regression in melanoma that may lead to an erroneous diagnosis of lymphoma and discuss the finding of oligoclonal T-cell expansion in regressed melanocytic lesions.

A study of eleven cutaneous malignant melanomas in adults with small-cell morphology: emphasis on diagnostic difficulties and unusual features.

AIMS: To describe the clinicopathological and immunohistochemical features of cutaneous malignant melanomas with a pure or mixed small-cell pattern in 11 adult patients, and to discuss the diagnostic difficulties encountered. METHODS AND RESULTS: Haematoxylin and eosin-stained sections of each case of cutaneous small-cell malignant melanoma, together with locally recurrent skin lesions and, where available, metastatic deposits, were re-examined. Available immunohistochemical sections were evaluated. Clinical follow-up data were obtained in each case. One patient presented with metastatic disease, the others presented with cutaneous lesions. Suggested initial diagnoses included malignant melanoma, non-Hodgkin's lymphoma, Merkel cell carcinoma and sarcoma. All the tumours were in the vertical growth phase. Nine had a junctional component, often inconspicuous. The lesions showed either a pure small-cell pattern or a mixed pattern with more conventional areas. In one case, there was colonization of a basal cell carcinoma by invasive malignant melanoma. Variable retention of small-cell morphology in local recurrences and metastases was observed, although in some cases more typically pleomorphic cells were present. In the cases tested, there was strong immunostaining for S100 protein and NKI-C3, and variable immunostaining for HMB45 and Melan-A. Non-melanocytic markers were negative. CONCLUSIONS: The possibility of a small-cell malignant melanoma should be considered in the assessment of cutaneous and non-cutaneous small-cell neoplasms. The correct diagnosis requires careful evaluation for junctional activity, melanin production and the use of a panel of melanocytic markers.

Follicular lymphoid hyperplasia of the hard palate and oral mucosa: report of three cases and a review of the literature.

AIMS: To bring to wider attention this uncommon, poorly understood entity which may closely resemble, clinically and morphologically, follicular lymphoma. METHODS AND RESULTS: We report three cases of follicular lymphoid hyperplasia of the hard palate and oral mucosa which caused diagnostic difficulties for the referring pathologists. The clinicopathological features are described and integrated into a review of the 16 previously recorded cases. The condition most commonly presents as a slowly growing mass situated in the posterior hard palate but may present with multicentric oral lesions and lymphadenopathy. Morphologically, it is characterized by a dense follicular lymphoid infiltrate within the lamina propria which may show the classical features of benign reactive hyperplasia, but not uncommonly, indistinct germinal centres, ill-defined mantles and a lack of tingible-body macrophages are features which may lead to an erroneous diagnosis of follicular lymphoma. CONCLUSIONS: Follicular lymphoid hyperplasia of the palate is a poorly recognized entity which is frequently confused with follicular lymphoma. Awareness of the entity combined with the use of immunohistochemistry for immunoglobulin light chains and bcl-2 protein allows a correct diagnosis to be made avoiding extensive investigation and aggressive treatment to the patient.

Basement-membrane-related peri-vascular matrices not organised as a basal lamina: distribution in malignant tumours and benign lesions.

Peri-vascular matrices having a finely textured granular substructure have been identified in 27 human lesions: these were mostly malignancies but included benign tumours and reactive processes. The matrices were defined as stromal components surrounding endothelium and pericytes, and lying between vessels and adjacent lesional cells. They were identified as having a finely textured, uniform and moderately dense substructure, and differed from a conventional basal lamina expected at these sites by the absence of the typical lamina densa/lamina lucida configuration. By light microscope immunohistochemistry, vessels stained positively for laminin and collagen IV, two of the main proteins characterising a conventional basal lamina. The present observations emphasise the following. 1) The proteins laminin and collagen IV can be found in peri-vascular locations which have a finely textured granular substructure, and which have clearly defined ultrastructural differences from a conventional basal lamina. 2) While conventional light microscope immunohistochemistry demonstrates the presence and cellular location of proteins, electron microscopy is helpful for giving information on their physical organisation. 3) Peri-vascular granular matrices have a widespread distribution in malignant tumours but also exist in benign tumours and reactive lesions. This paper briefly discusses the possible functions of these matrices as modulators of cell biological processes.

Malignant melanoma showing ganglioneuroblastic differentiation: report of a unique case.

We report a case of metastatic malignant melanoma in an inguinal lymph node, expressing ganglioneuroblastic differentiation. This was characterized by the presence of discrete nests and islands of large ganglion cells with abundant cytoplasm and eccentric nuclei with prominent nucleoli admixed with smaller primitive neuroblasts. The cells were separated by pale pink fibrillar material representing neuritic cell processes. These foci of ganglioneuroblastoma were seen over a background of an otherwise typical metastatic epithelioid, focally melanotic, malignant melanoma. Immunohistochemistry showed positivity for neurofilament, synaptophysin, chromogranin, vasoactive intestinal peptide, and glial fibrillary acidic protein in the areas with ganglioneuroblastic differentiation, but not in the melanocytic component. Conversely, HMB45 positivity was expressed by the melanocytic cells only. S-100 protein and Melan-A, a putative melanocytic marker, showed positivity in both melanocytic and ganglioneuroblastic components. Ultrastructurally, neuritic cell processes and dense core neurosecretory granules were identified in the ganglionic and neuroblastic cells. A subsequent nodal metastasis in the same region showed focal neuroblastic differentiation without the ganglionic element. No evidence of neuronal or ganglionic differentiation was seen in the primary skin melanoma.

Extra-medullary myeloid tumour (granulocytic sarcoma) is often misdiagnosed: a study of 26 cases.

AIMS: To describe the clinicopathological and immunophenotypic features of 26 cases of extra-medullary myeloid tumour (EMMT)/granulocytic sarcoma, which remains poorly recognized and is frequently confused with malignant lymphoma, and to discuss the main diagnostic problems experienced by the referring pathologist. METHODS AND RESULTS: Haematoxylin and eosin (H & E) sections of 26 cases of EMMT were re-examined. Immunostains for myeloperoxidase, lysozyme, neutrophil elastase, LCA, CD79a, CD20, CD43, CD45RO, CD3, CD30, CD15, CD68, MAC387, VS38C, MIC2, and the Leder stain for naphthol-ASD-chloroacetate esterase were performed on all cases. Clinical and follow-up data were obtained through a questionnaire to the referring pathologist or from the notes of the patients where available. In the 10 cases with known myeloproliferative disease, the initial diagnosis was correct in 10 whereas all cases presenting with EMMT without a previous history of myeloproliferative disorder had an initial incorrect diagnosis. The most common suggested diagnosis was that of a non-Hodgkin's lymphoma. The morphology of the tumours varied from well differentiated which included all stages of myeloid differentiation to poorly differentiated or blastic showing little or no evidence of myeloid differentiation. The proportion of positive cells for each stain varied. Chloroacetate esterase, myeloperoxidase and CD15 stained a large proportion of cells of the majority of the well differentiated tumours and a smaller proportion of the poorly differentiated/blastic tumours with very focal staining of some of the cases. Lysozyme and CD43 were the most sensitive of the markers staining a large proportion of cells of the majority of the tumours in both groups. Neutrophil elastase was the least sensitive of the markers of myeloid differentiation. CD79a, CD20, CD3 and CD30 were negative in all cases. CD43 was positive in all cases. CD68 stained a substantial number of cells in the majority of tumours. A smaller proportion of the tumours stained with MAC387. Four of the tumours showed positivity for MIC2. One tumour was positive for VS38C. CONCLUSION: This series documents continuing difficulties in the diagnosis of EMMT. Even well differentiated tumours are frequently mistakenly diagnosed as malignant lymphomas when they present without any history of antecedent myeloproliferative disorder. Careful evaluation of morphology for evidence of myeloid differentiation and a high index of suspicion when confronted with a less differentiated neoplasm are required to avoid this important diagnostic error. We suggest that a panel which includes chloroacetate-esterase, myeloperoxidase, lysozyme and CD43, together with other B- and T-lineage markers, in particular CD79a and CD3 should be used to confirm the diagnosis.

Histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease): continuing diagnostic difficulties.

AIMS: To describe the clinicopathological and immunophenotypic features of 25 cases of Kikuchi-Fujimoto disease (K-F), which remains a poorly recognized entity and is still frequently confused with malignant lymphoma, and to discuss the main diagnostic problems experienced by the referring pathologist. METHODS AND RESULTS: Haematoxylin and eosin sections of 27 lymph node biopsies were re-examined. Immunostains for B-lymphocytes, T-lymphocytes and macrophages were performed. Clinical and follow-up data were obtained through a questionnaire to the referring pathologist or from the patients' notes where available. The suggested initial diagnoses are discussed. The lymph nodes showed a necrotizing process characterized by patchy or confluent areas of necrosis associated with karyorrhexis and absence or paucity of granulocytes. This was associated with a proliferation of large blastic cells consisting of a mixture of T-lymphocytes and histiocytes. Fragmentation of the biopsy was a frequent feature. The diagnosis of K-F was suggested by the referring pathologist in three cases only. The most common suggested diagnosis was that of a non-Hodgkin's lymphoma. CONCLUSION: This series documents continuing difficulties in the diagnosis of Kikuchi-Fujimoto disease in the UK and emphasizes that cases are still being mistakenly diagnosed as malignant lymphomas. The diagnosis of Kikuchi-Fujimoto disease merits active consideration in any nodal biopsy showing fragmentation, necrosis and karyorrhexis, especially in young women presenting with cervical lymphadenopathy.

Diagnostic lessons of mucosal melanoma with osteocartilaginous differentiation.

AIMS: To document the clinical, morphological and immunohistochemical features of two cases of primary mucosal melanoma with osteocartilaginous differentiation. MATERIALS AND METHODS: Two cases of mucosal melanoma with cartilage and bone formation are reported, one arising in the vagina of a 79-year-old woman and one in the oral cavity of a 67-year-old man. The vaginal melanoma exhibited only cartilaginous differentiation. The oral cavity mucosal melanoma exhibited both bone and cartilage formation and was remarkable for its multifocality, long history not associated with metastases and its lengthy manifestation of dual morphologies: some of the tumours were typical in situ/invasive melanotic melanomas whilst the others were composed of amelanotic spindle and epithelioid cells with osteocartilaginous tissue. One of the lesions exhibited in situ and invasive melanoma with transition to an osteogenic tumour in places. The patient also developed nonosteogenic malignant melanomas in the nasal cavity and nasopharynx. CONCLUSIONS: Malignant melanomas showing foci of osteocartilaginous differentiation are extremely rare with only 18 cases reported. Primary mucosal malignant melanomas of vagina and oral cavity showing osteocartilaginous differentiation have not previously been documented. Primary vaginal melanoma with cartilaginous differentiation must be distinguished from primary malignant mixed Müllerian tumour whilst malignant change in a pleomorphic adenoma, sarcomatoid carcinoma, osteogenic sarcoma and mesenchymal chondrosarcoma are included in the differential diagnosis of primary oral mucosal melanomas with osteocartilaginous differentiation. In this context, immunohistochemistry using antibodies to cytokeratin, S100 protein and MIC2 is of value.

Adenocarcinoma of the rete testis.

Adenocarcinoma of the rete testis is a rare testicular tumour, which often presents late, with metastatic disease present in a significant proportion of patients. We record the clinicopathological findings in a man who presented with an apparently localized testicular tumour. He however went on to develop a rapidly progressive local recurrence and metastatic disease, despite primary radiotherapy. Detailed immunohistochemical examination was performed and we record positivity of this tumour for the recently developed markers HBME1 and thrombomodulin.

Comparative genomic hybridisation of ductal carcinoma in situ of the breast: identification of regions of DNA amplification and deletion in common with invasive breast carcinoma.

Comparative genomic hybridisation has been used to map copy number changes in nine cases of ductal carcinoma in situ of the breast obtained from wax-embedded archive material. A wide variety of abnormalities were detected including gain of regions of 1q, 17q, 19q, 20p and 20q and loss on 13q, 14q, 17p, 16q and 22q. Amplification of areas on 10p, 8q and 20q were also observed. Chromosomal alterations were more frequent in higher grade DCIS and closely resemble those previously detected in invasive breast cancer using the same technique. These data provide strong molecular support for the view that DCIS is a precursor lesion of invasive breast carcinoma.

Mutation of the TP53 gene and allelic imbalance at chromosome 17p13 in ductal carcinoma in situ.

A panel of 36 cases of preinvasive breast lesions, including 35 cases of ductal carcinoma in situ (DCIS), has been examined for mutation of TP53, allelic imbalance (AI) on 17p13, and expression of TP53, in a number of cases, has been studied using immunohistochemistry. Areas of DCIS, with or without adjacent invasive or benign cells, have been separately microdissected from paraffin-embedded sections and analysed by PCR for genetic changes to chromosome 17p13. TP53 mutations and AI on 17p have been identified in cases of 'pure' DCIS as well as those with associated invasive carcinoma and, furthermore, have been identified in well-differentiated lesions as well as poorly differentiated ones.