Contiguous Tumor Research Articles

Characterization of Classic Meningioma with Use of Conventional Magnetic Resonance and Diffusion Tensor Imaging

Introduction: The conventional magnetic resonance imaging (MRI) method is widely considered ‘with limited success’ in differentiating the meningioma types but may fail to localize the tumor occupation of white-matter fiber bundles accurately. Diffusion tensor imaging (DTI) is considered as an imaging modality that may elucidate the microstructure of brain tumors. We provide characteristics of meningioma using DTI-based-three-dimensional tracing of white matter to portray meningioma in a noninvasive approach and its structural contact to contiguous tumors and elucidate the influence of occupying lesions on white-matter fiber bundles. Case Presentation: A 28-year-old female presented with visuospatial disturbances and persistent headaches for 2 years. Conventional and advanced MRI studies were performed. Diffusion-weighted Images (DWI) and Apparent Diffusion Coefficient (ADC) values were measured in the lesion using routine MRI sequences. Advanced MRI using DTI was also performed. Conventional MRI outcomes showed tumor parenchyma, peritumoral edema, and compression on the circumnavigated brain tissue. There was hyperintense on DW trace image and isointense on ADC map. On T2-weighted image (T2WI) and Fluid-Attenuated Inversion Recovery (FLAIR) images, there was an increased signal intensity that demonstrated an extra-axial lesion, while T1-weighted imaging signals showed hypointensity. DTI fractional anisotropy (FA) marker is an unclear optic radiation in the concerned area, indicating the shift or destruction of the optic radiation. The mean FA values of solid-enhancing areas of meningioma were 0.28 ± 0.17. Mean ADC values (103 mm2/s) were 0.764 ± 0.172. Conclusions: Classic meningioma in this case has low intratumoral FA and high ADC. DTI displayed that intratumoral microscopic water motion is disorganized.

Establishing guidelines for sentinel lymph node ultrastaging in endometrial cancer

BackgroundMany sentinel lymph node (SLN) ultrastaging protocols for endometrial cancer exist, but there is no consensus method.ObjectiveThis study aims to develop guidelines for size criteria in SLN evaluation for endometrial...

Seborrheic keratosis, solar lentigo and syringoma: A case report of this uncommon collision tumor

When two or more distinct tumors occur in a single lesion, at one site, it is termed a collision or contiguous tumors, they are often an unexpected finding and may represent a diagnostic challenge, as clinical and histological presentations do not always coincide.

Secondary malignancy in a vulva cancer patient – HPV-induced field cancerization: A case report

Background: Human papillomavirus (HPV) infection is associated with oropharyngeal and anogenital cancers in men and women. Approximately 90% of all cervical cancers are attributed to high-risk HPV infections, and 60% of squamous cell carcinomas (SCC) of the vulva, vagina, anus, and penis are due to HPV infection. Case presentation: We present the case of a 26-year-old with retroviral disease managed for locally advanced vulva cancer on external beam radiotherapy followed by wide excision of the residual tumor and bilateral inguino femoral nodal dissection. She later presented with a history of foul-smelling vaginal discharge. A biopsy confirmed moderately differentiated squamous cell carcinoma of the cervix clinically and radiologically staged at 2B and 3B, respectively. She was scheduled to start chemotherapy with carboplatin and paclitaxel after blood transfusion due to anemia. Discussion: Field cancerization was coined by Slaughter et al. to describe the existence of generalized carcinogen-induced early genetic changes in the epithelium from which multiple independent lesions occur, leading to the development of multifocal tumors. In some cases, multiple contiguous tumor foci coalesce, hence the lateral spread of squamous cell cancers. It was also observed that normal-looking cells near malignant cells were histologically abnormal and therefore were part of the transformed cells in a particular tumor field and consequently were responsible for the occurrence of local tumor recurrences. Conclusion: Field cancerization is a well-known and well-documented process of malignant transformation. Several studies have confirmed the importance of this phenomenon in tumor development. Surveillance is the key to detecting early recurrence and secondary malignancies.

Tumor segmentation via enhanced area growth algorithm for lung CT images

BackgroundSince lung tumors are in dynamic conditions, the study of tumor growth and its changes is of great importance in primary diagnosis.MethodsEnhanced area growth (EAG) algorithm is introduced to segment the lung tumor in 2D and 3D modes on 60 patients CT images from four different databases by MATLAB software. The contrast augmentation, color intensity and maximum primary tumor radius determination, thresholding, start and neighbor points’ designation in an array, and then modifying the points in the braid on average are the early steps of the proposed algorithm. To determine the new tumor boundaries, the maximum distance from the color-intensity center point of the primary tumor to the modified points is appointed via considering a larger target region and new threshold. The tumor center is divided into different subsections and then all previous stages are repeated from new designated points to define diverse boundaries for the tumor. An interpolation between these boundaries creates a new tumor boundary. The intersections with the tumor boundaries are firmed for edge correction phase, after drawing diverse lines from the tumor center at relevant angles. Each of the new regions is annexed to the core region to achieve a segmented tumor surface by meeting certain conditions.ResultsThe multipoint-growth-starting-point grouping fashioned a desired consequence in the precise delineation of the tumor. The proposed algorithm enhanced tumor identification by more than 16% with a reasonable accuracy acceptance rate. At the same time, it largely assurances the independence of the last outcome from the starting point. By significance difference of p < 0.05, the dice coefficients were 0.80 ± 0.02 and 0.92 ± 0.03, respectively, for primary and enhanced algorithms. Lung area determination alongside automatic thresholding and also starting from several points along with edge improvement may reduce human errors in radiologists’ interpretation of tumor areas and selection of the algorithm’s starting point.ConclusionsThe proposed algorithm enhanced tumor detection by more than 18% with a sufficient acceptance ratio of accuracy. Since the enhanced algorithm is independent of matrix size and image thickness, it is very likely that it can be easily applied to other contiguous tumor images.Trial registrationPAZHOUHAN, PAZHOUHAN98000032. Registered 4 January 2021, http://pazhouhan.gerums.ac.ir/webreclist/view.action?webreclist_code=19300

Human herpes virus 8-negative effusion-based lymphoma in a patient with persistent serous effusions.

Diffuse large B-cell lymphoma is the most common histologic diagnosis among the aggressive lymphomas, accounting for 30% of all lymphomas. Human herpes virus 8-negative effusion-based lymphoma (HHV8-negative EBL) is a rare form of lymphoma, under recognized and still not well characterized in the literature. In contrast to primary effusion lymphoma (PEL), HHV8-negative EBL is characterized by malignant effusion in essentially serous body cavity with no detectable contiguous tumor masses and is no associated with human immunodeficiency virus and HHV8 infections. The presence of comorbid medical conditions can hide this type of lymphoma and made diagnosis more challenging. Here, we describe a rare case of an 82-year-old male suffering from peritoneal and pleural effusion and Hepatitis B virus related cirrhosis diagnosed with HHV8-negative EBL.

Preemptive Femoral-Femoral Crossover Grafting of Artery and Vein Before Pelvic Exenterative Surgery for Locally Advanced and Recurrent Pelvic Malignancy Involving the Aortoiliac Axis.

Achieving a negative resection through a pelvic exenteration for a recurrent or an advanced pelvic malignancy offers the potential for cure. Exenterative surgical units have expanded the boundaries and redefined what constitutes resectable disease through improved surgical technique. In selected cases, contiguous tumor involvement of the aortoiliac axis requires en bloc resection and subsequent vessel reconstruction. However, vascular reconstruction can be challenging in a contaminated field during an extended radical resection. The aim of this Technical Note is to describe a novel method in the management of patients with recurrent or advanced pelvic malignancy involving the aortoiliac axis by performing preemptive femoral-femoral arterial and venous crossover grafts, with adjunctive arteriovenous loop fistula formation before undergoing an extended radical pelvic resection 4 weeks later. Four patients have undergone preemptive femoral-femoral arterial and venous crossover grafts at our institution (median age = 60 y (range, 47-66 y); 2 women). There were no early complications, and all of the patients subsequently underwent extended radical pelvic resections for a pelvic malignancy. Preemptive vascular reconstruction before major pelvic surgery reduces the risk of graft infection because this method avoids the wounds being contaminated by GI or genitourinary organisms. Other advantages to this technique include a reduction in the overall operating time for the pelvic exenteration, a significant reduction in the ischemia time to the lower limbs, and ensuring that the grafts are patent before embarking on major intra-abdominal surgery.

2282 Hepatocellular Carcinoma With Rare Duodenal Metastases

INTRODUCTION: Hepatocellular carcinoma is a decompensation of cirrhosis. We present a patient with HCC, presenting with anemia, found to have metastatic disease to the duodenum. CASE DESCRIPTION/METHODS: 67 y/o male with hepatitis C cirrhosis, complicated by HCC, presented with anemia and melena. HCC was diagnosed 1 year prior, with a 3.8 cm left lobe lesion, portal venous thrombus, and a LIRADS-4 right lobe lesion, initiated on palliative chemotherapy. Recent MRI demonstrated infiltrative HCC involving nearly the entire left lobe of the liver; tumor and bland thrombus within the portal system involving the confluence of the portal veins, left, and to a lesser extent, right portal vein. Exam revealed guaiac positive brown stool. Labs revealed hemoglobin 6.0 g/dL (baseline 12g/dL), MCV 93, BUN 17 mg/dL, Cr 1.2 mg/dL. Endoscopy demonstrated 3 superficial duodenal bulb ulcers, 2mm-3mm, with a visible vessel, treated; no varices seen. Repeat EGD demonstrated multiple closely associated pedunculated polypoid lesions with superimposed ulcerations with irregular appearing surrounding mucosa; biopsies without evidence of malignancy. Given the abnormal appearance, repeat EGD with biopsies was performed, revealing metastatic hepatocellular carcinoma in multiple fragments of the duodenal mucosa. DISCUSSION: Hepatocellular carcinoma is the most common primary liver malignancy. The most significant risk factor for HCC is pre-existing cirrhosis. Lung, bone and lymph nodes are the most common metastatic sites of HCC; metastatic disease to the duodenum is exceedingly rare (1). Of &gt;7000 cases of HCC identified in Taiwan between 1996-2009, &lt; 1%, or just 21 cases, revealed duodenal disease (1). GI involvement is most frequently a result of direct invasion by contiguous tumor, with right lobe disease most commonly extending to the duodenum and left lobe disease most commonly extending to the stomach (1). Rarely, as seen in our patient, duodenal disease can be a location of metastatic disease without direct contact. Wall thickening appreciated on imaging should prompt consideration of gastrointestinal involvement. It has been suggested that portal vein thrombosis may be an indication of hematogenous spread of tumor, in addition to being a poor prognostic indicator. Duodenal masses, ulcerations or bleeding should raise suspicion for duodenal metastasis, and portends a very poor prognosis.

Three-dimensional analysis reveals two major architectural subgroups of prostate cancer growth patterns

The Gleason score is one of the most important parameters for therapeutic decision-making in prostate cancer patients. Gleason growth patterns are defined by their histological features on 4- to 5-µm cross sections, and little is known about their three-dimensional architecture. Our objective was to characterize the three-dimensional architecture of prostate cancer growth patterns. Intact tissue punches (n = 46) of representative Gleason growth patterns from radical prostatectomy specimens were fluorescently stained with antibodies targeting Keratin 8/18 and Keratin 5 for the detection of luminal and basal epithelial cells, respectively. Punches were optically cleared in benzyl alcohol–benzyl benzoate and imaged using a confocal laser scanning microscope up to a depth of 500 µm. Gleason pattern 3, poorly formed pattern 4, and cords pattern 5 all formed a continuum of interconnecting tubules in which the diameter of the structures and the lumen size decreased with higher grades. In fused pattern 4, the interconnections between the tubules were markedly closer together. In these patterns, all tumor cells were in direct contact with the surrounding stroma. In contrast, cribriform Gleason pattern 4 and solid pattern 5 demonstrated a three-dimensional continuum of contiguous tumor cells, in which the vast majority of cells had no contact with the surrounding stroma. Transitions between cribriform pattern 4 and solid pattern 5 were seen. There was a decrease in the number and size of intercellular lumens from cribriform to solid growth pattern. Glomeruloid pattern 4 formed an intermediate structure consisting of a tubular network with intraluminal epithelial protrusions close to the tubule splitting points. In conclusion, three-dimensional microscopy revealed two major architectural subgroups of prostate cancer growth patterns: (1) a tubular interconnecting network including Gleason pattern 3, poorly formed and fused Gleason pattern 4, and cords Gleason pattern 5, and (2) serpentine contiguous epithelial proliferations including cribriform Gleason pattern 4 and solid Gleason pattern 5.

Prostate specific membrane antigen (PSMA) expression in vena cava tumour thrombi of clear cell renal cell carcinoma suggests a role for PSMA-driven tumour neoangiogenesis.

Clear cell renal cell carcinoma (ccRCC) is a malignant renal neoplasm with a peculiar propensity to propagate as a contiguous tumor extension via the renal vein and inferior vena cava, occasionally reaching the right atrium. This intravascular tumor extension, often referred to as a tumor thrombus, represents the active growing front of the cancer. Prostate specific membrane antigen (PSMA), a glycoprotein that is extensively used in prostate cancer diagnostics, is a useful vascular marker for a variety of solid tumors. It is expressed in renal carcinomas. The aim of the current investigation was to analyse and compare the expression of PSMA at the growing front of the vena cava tumor extension with that found in the primary renal lesion. Immunohistochemical (IHC) analysis of PSMA and CD34 was performed on archived paraffin embedded vena cava tumour thrombus tissue and matching renal tumours. These specimens were collected from radical nephrectomies of 10 patients with vena cava invasive (pT3b) ccRCC in a large tertiary hospital in Australia. Quantitative and qualitative morphometric analysis of PSMA IHC expression was performed with Aperio ImageScope morphometry using intensity and positive pixel counts of CD34 and PSMA from the IVC tumour slides and the corresponding renal tumour mass. PSMA and CD34 immunostaining were noted in the neovasculature of IVC tumour and renal tumour tissue. There was a higher PSMA/CD34 positive pixel count ratio noted in IVC tumour tissue when compared to renal tumour tissue. PSMA showed consistently increased expression in vena cava tumour, in comparison with the renal tumour mass. Intravascular venous tumour extension expresses PSMA more intensely compared to intrarenal tumour tissue neovasculature. Our data suggest a possible mechanism for PSMA in neoangiogenesis and local progression of ccRCC and therefore its usefulness as a biomarker of neoangiogenesis for future diagnostic and therapeutic advancements.

Supracarinal dissection of the oesophagus and lymphadenectomy by MIE.

Since 1995, video-assisted thoracoscopic oesophagectomy (VATS), according the same surgical principles as the Japanese open surgery, has been completed in 700 patients with oesophageal cancer. Our indication for VATS is (I) no extensive pleural adhesion; (II) no contiguous tumor spread; (III) pulmonary function capable of sustaining single-lung ventilation, and (IV) non radiated patients. We use 4 ports around a 5 cm mini-thoracotomy on 5th intercostal space. We laid emphasis on utilizing magnifying effect of video (5 to 20 magnifications), obtained by positioning the camera at close vicinity to the dissection. Magnified view facilitates recognizing the fine layer structure of the mediastinum. The dissection should be performed following this layer structure just like open the page of a book. Tearing the layer makes the dissection irrational and cause unnecessary bleeding and invasiveness. The microanatomies we recognize during upper mediastinal dissection are (I) the most outer layer below the mediastinal pleura are branches from the vagus nerve and thoracic sympathetic trunk; (II) there is no vessel flow in the nerves or out, in the field of dissection; (III) the ideal layer of dissection along the nerve is exposing the epineurium; (IV) the strongest fixing structures in the mediastinum are the vagal nerves and nerves form thoracic sympathetic trunk; (V) the stump of thoracic duct shows particular appearance because of the intramural smooth muscle; (VI) the lymphonodes in the mediastinum are fixed strongly with nerves and gently with vessels; (VII) the aorta is covered with fine fibrous membrane consisting of branches form thoracic sympathetic trunk, etc. Magnified view shows the microstructure of the lymph node such as the afferent lymphatics penetrating the capsule and the hilum structure consisting the efferent lymphatics, artery, vein and nerve. The direction of the hilum of nodes is defined in each region. Therefore, understanding the hilum direction facilitates rational dissection. The hospital mortality was four patients (0.6%). The rate of regional control was 95%. The 5-year survival rates of the patients with pStage 0, 1, 2, 3, 4 were 92%, 88%, 69%, 52% and 24%, respectively, which were favorably compared with open surgery.

YM155 induces apoptosis through proteasome-dependent degradation of MCL-1 in primary effusion lymphoma

Primary effusion lymphoma (PEL) is a lymphoma that shows malignant effusion in body cavities without contiguous tumor masses and has a very poor prognosis. We recently developed a novel drug screening system using patient-derived xenograft (PDX) cells that maintained the primary cell phenotype better than cell lines. This screening is expected to discover anti-tumor drugs that have been overlooked by conventional screening using cell lines. We herein performed this screening to identify new therapeutic agents for PEL.We screened 3518 compounds with known pharmaceutical activities based on cytotoxic effects on PDX cells of PEL and selected YM155, a possible survivin inhibitor. It exerted strong anti-tumor effects in PDX cells and three cell lines of PEL; the GI50 of YM155 was 1.2–7.9nM. We found that YM155 reduced myeloid cell leukemia-1 (MCL-1) protein levels prior to decreasing survivin levels, and this was inhibited by a proteasome inhibitor. The knockdown of MCL-1 by siRNA induced cell death in a PEL cell line, suggesting the involvement of decreased MCL-1 levels in YM155-induced cell death. YM155 also induced the phosphorylation of ERK1/2 and MCL-1, and a MEK1 inhibitor inhibited the phosphorylation of ERK1/2, degradation of MCL-1, and YM155-induced apoptosis. These results indicate that YM155 induces the proteasome-dependent degradation of MCL-1 through its phosphorylation by ERK1/2 and causes apoptosis in PEL cells. Furthermore, a treatment with YM155 significantly inhibited the development of ascites in PEL PDX mice. These results suggest the potential of YM155 as an anti-cancer agent for PEL.

Strategic surgical planning for resection of a large adrenal cortical carcinoma

Adrenal cortical carcinoma (ACC) is a rare malignancy with an annual incidence of approximately 0.7 cases per million in the United States (1). While these tumors can develop at any age, there is a recognized bimodal age distribution for ACC with the first peak occurring before age 5 years and the second peak in the 4 th –5 th decade of life (2). Despite accounting for only 0.2% of cancer-related deaths per year in the United States, ACC has a very poor prognosis (3). Over half of patients present with advanced disease and overall survival remains poor even with surgical resection (4,5). Management of ACC requires a multidisciplinary treatment approach. Surgical resection offers the only potentially curative treatment option even though recurrences will still occur in up to 70–80% (6,7). Age older than 55 years, positive resection margin, lymph node positive disease, resection of a contiguous organ, poorly-differentiated tumors, and distant metastatic disease are independent predictors of worse prognosis in patients who undergo surgical resection (4). Due to the proximity of the adrenal gland to surrounding anatomic structures, the need for combined resection ACC with liver, pancreas, kidney are common. Hence, surgical resection of ACC carries significant mortality and morbidity.

Synchronous Tumors of the Cerebellopontine Angle

Synchronous tumors of the cerebellopontine angle (CPA) are very rare and inconsistently described. We present 2 cases of contiguous vestibular schwannoma (VS) and meningioma and a systematic literature review of all multiple CPA tumors. Retrospective chart review and systematic literature review were performed. A 64-year-old woman and a 42-year-old man presented with symptoms referable to the CPA. Magnetic resonance imaging in both patients revealed 2 separate contiguous tumors. Retrosigmoid craniotomy and tumor removal in each case confirmed VS and meningioma. Systematic literature review identified 42 previous English-language publications describing 46 patients with multiple CPA tumors. Based on Frassanito criteria, there were 4concomitant tumors (8%), 16 contiguous tumors (33%), 3collision tumors (6%), 13 mixed tumors (27%), and 11 tumor-to-tumor metastases (23%). Extent of resection was gross total in 16 cases and subtotal in 16 cases (50% each). Unfavorable House-Brackmann grade III-VI function was documented in 27% overall and in 33% of patients with VS and meningioma, a marked increase from the observed range in isolated VS. Multiple CPA tumors are rare, heterogeneous lesions with a marked predisposition toward poor facial nerve outcomes, potentially attributable to a paracrine mechanism that simultaneously drives multiple tumor growth and increases invasiveness or adhesiveness at the facial nerve-tumor interface. Preceding nomenclature has been confounding and inconsistent; we recommend classifying all multiple CPA tumors as "synchronous tumors," with "schwannoma with meningothelial hyperplasia" or "tumor-to-tumor metastases" reserved for rare, specific circumstances.

Secondary debulking surgery for isolated pelvic nodal recurrence requiring external iliac vein excision and reconstruction in a patient with ovarian cancer

ObjectiveWe report the details of a cytoreduction technique for pelvic lymph node recurrence with involvement of the external iliac vein (EIV) requiring a partial resection and reconstruction of the EIV. MethodsA 51-year-old woman presented with ovarian cancer and isolated nodal recurrence located on the right side of the pelvis. As the tumor had infiltrated the EIV wall, we performed the EIV excision and reconstruction using an autogenous graft. ResultsEIV reconstruction was achieved using a right ovarian vein patch. No intra- or early postoperative complications occurred. A postoperative enhanced magnetic resonance imaging examination confirmed the patency of the EIV. ConclusionAn en bloc EIV excision and reconstruction for contiguous tumor involvement seems to be a feasible and safe surgical option.

Tumor de Colisão de Odd – Dermatofibroma e Nevo

Um tumor de colisão ou tumor contiguo ocorre quando dois ou mais tumores cutâneos coexistem numa lesão única. Estes tumores têm habitualmente características clinicas e histológicas atípicas, dificultando o diagnóstico. Apesar de terem sido descritas diferentes combinações de tumores de colisão, descrevemos um caso raro de um tumor de colisão localizado no dorso com associação de um nevo intradérmico a um dermatofibroma. Julgamos que se trata da primeira publicação desta combinação.

Spatial genomic heterogeneity in diffuse intrinsic pontine and midline high-grade glioma: implications for diagnostic biopsy and targeted therapeutics.

IntroductionDiffuse intrinsic pontine glioma (DIPG) and midline high-grade glioma (mHGG) are lethal childhood brain tumors. Spatial genomic heterogeneity has been well-described in adult HGG but has not been comprehensively characterized in pediatric HGG. We performed whole exome sequencing on 38-matched primary, contiguous, and metastatic tumor sites from eight children with DIPG (n = 7) or mHGG (n = 1) collected using a unique MRI-guided autopsy protocol. Validation was performed using Sanger sequencing, Droplet Digital polymerase-chain reaction, immunohistochemistry, and fluorescent in-situ hybridization.ResultsMedian age at diagnosis was 6.1 years (range: 2.9–23.3 years). Median overall survival was 13.2 months (range: 11.2–32.2 months). Contiguous tumor infiltration and distant metastases were observed in seven and six patients, respectively, including leptomeningeal dissemination in three DIPGs. Histopathological heterogeneity was evident in seven patients, including intra-pontine heterogeneity in two DIPGs, ranging from World Health Organization grade II to IV astrocytoma. We found conservation of heterozygous K27M mutations in H3F3A (n = 4) or HIST1H3B (n = 3) across all primary, contiguous, and metastatic tumor sites in all DIPGs. ACVR1 (n = 2), PIK3CA (n = 2), FGFR1 (n = 2), and MET (n = 1) were also intra-tumorally conserved. ACVR1 was co-mutated with HIST1H3B (n = 2). In contrast, PDGFRA amplification and mutation were spatially heterogeneous, as were mutations in BCOR (n = 1), ATRX (n = 2), and MYC (n = 1). TP53 aberrations (n = 3 patients) varied by type and location between primary and metastatic tumors sites but were intra-tumorally conserved. ConclusionSpatial conservation of prognostically-relevant and therapeutically-targetable somatic mutations in DIPG and mHGG contrasts the significant heterogeneity of driver mutations seen in adult HGG and supports uniform implementation of diagnostic biopsy in DIPG and mHGG to classify molecular risk groups and guide therapeutic strategy.Electronic supplementary materialThe online version of this article (doi:10.1186/s40478-015-0269-0) contains supplementary material, which is available to authorized users.

Nodular Fasciitis Complicating a Staged Surgical Excision of Dermatofibrosarcoma Protuberans.

Dermatofibrosarcoma protuberans (DFSP) is an unusual spindle cell tumor with a high rate of local recurrence with traditional excision. Fortunately, Mohs micrographic surgery yields excellent cure rates for this neoplasm due to contiguous tumor spread and meticulous tumor mapping and margin analysis. We present the unique case of a patient treated with a modified Mohs technique with an analysis of the final margin with permanent sections, who developed a spindle cell neoplasm in the margins of her second stage excision consistent with nodular fasciitis. Distinguishing residual DFSP from a benign reactive process was an essential and challenging component of this patient's management.

Case Presentation of Concomitant and Contiguous Adenomatoid Odontogenic Tumor and Focal Cemento-Ossifying Dysplasia.

A 24 year-old male was presented for the diagnosis of an asymptomatic bony expansion in relation to the right maxillary canine and first premolar. The unilocular radiolucent lesion with central foci of calcification had caused divergence of canine and first premolar roots without any resorption. This case report details a diagnosis of two distinct disease processes of different cellular origin namely, focal cemento-ossifying dysplasia and adenomatoid odontogenic tumor in a previously unreported concomitant and contiguous relationship. The diagnosis was determined by a combination of clinical, radiographic, histopathological and surgical evidence. This case highlights two points, first the need to examine all mixed radiolucent-radiopaque lesions with advanced imaging techniques to assess the number and extent of the lesions prior to treatment planning. Second a likely role of periodontal ligament as the tissue source for odontogenic epithelial cells and mesenchymal stem cells required for the development of odontogenic tumors and cemento-osseous dysplasias.

Membrane Transfer from Tumor Cells Overcomes Deficient Phagocytic Ability of Plasmacytoid Dendritic Cells for the Acquisition and Presentation of Tumor Antigens

The potential contribution of plasmacytoid dendritic cells (pDCs) in the presentation of tumor cell Ags remains unclear, and some controversies exist with regard to the ability of pDCs to phagocytose cell-derived particulate Ags and cross-present them to MHC class I-restricted T lymphocytes. In this study, we show that human pDCs, although inefficient in the internalization of cell membrane fragments by phagocytosis, can efficiently acquire membrane patches and associated molecules from cancer cells of different histotypes. The transfer of membrane patches to pDCs occurred in a very short time and required cell-to-cell contact. Membrane transfer also included intact HLA complexes, and the acquired Ags could be efficiently recognized on pDCs by tumor-specific CD8(+) T cells. Remarkably, pDCs isolated from human colon cancer tissues displayed a strong surface expression of epithelial cell adhesion molecule, indicating that the exchange of exogenous Ags between pDCs and tumor cells also can occur in vivo. These data demonstrate that pDCs are well suited to acquire membrane patches from contiguous tumor cells by a cell-to-cell contact-dependent mechanism that closely resembles "trogocytosis." This phenomenon may allow pDCs to proficiently present tumor cell-derived Ags, despite limited properties of endophagocytosis.