Expression of Claudin-4 and D2-40 and their significance in prostatic adenocarcinoma.

BACKGROUND: Claudins are a clan of proteins that are the most important component of tight junctions. The claudin-4 expression has been linked to tumour cell invasion and progression in a variety of primary malignancies. Evaluation of lymphovascular density (LVD) correlates with tumour aggressiveness and may correlate with prognosis. D2-40 is a highly specific marker of lymphatic vessels. AIMS: To evaluate the claudin-4 expression in relation to LVD by D2-40 expression and with clinicopathological parameters in prostatic adenocarcinoma. SETTINGS AND DESIGN: Prospective study. MATERIALS AND METHODS: 39 cases of prostatic adenocarcinoma were taken, the D2-40 and claudin-4 immunohistochemical stains were performed and correlation was done with clinicopathological parameters. STATISTICAL ANALYSIS USED: Statistical analyses such as mean, median, standard deviation, Mann-Whitney U test, Fischer exact test, Spearman's rank-order correlation coefficient, Chi-square test and T-test were used. RESULTS: The claudin-4 expression was seen higher in cases with higher Gleason score but it was statistically non-significant (P = 0.778). The claudin-4 expression did not correlate with any clinicopathological parameters. LVD in the peritumoral area was significantly higher as compared to the intratumoral area (P = 0.005). Intratumoral LVD and perineural invasion were found to be statistically significant (P = 0.048). CONCLUSION: The claudin-4 expression may correlate with adverse prognostic parameters. Higher lymphatic vessels can be responsible for the higher metastatic potential of prostatic adenocarcinomas.

Tumor cell invasion in blood vessels assessed by immunohistochemistry is related to decreased survival in patients with bladder cancer treated with radical cystectomy.

BACKGROUND: Lymphovascular invasion (VI) is an established prognostic marker for many cancers including bladder cancer. There is a paucity of data regarding whether the prognostic significance of lymphatic invasion (LVI) differs from blood vessel invasion (BVI). The aim was to examine LVI and BVI separately using immunohistochemistry (IHC), and investigate their associations with clinicopathological characteristics and prognosis. A secondary aim was to compare the use of IHC with assessing VI on standard HAS (hematoxylin-azophloxine-saffron) sections without IHC. METHODS: A retrospective, population -based series of 292 invasive bladder cancers treated with radical cystectomy (RC) with curative intent at Vestfold Hospital Trust, Norway were reviewed. Traditional histopathological markers and VI based on HAS sections were recorded. Dual staining using D2-40/CD31 antibodies was performed on one selected tumor block for each case. RESULTS: The frequency of LVI and BVI was 32 and 28%, respectively. BVI was associated with features such as higher pathological stages, positive regional lymph nodes, bladder neck involvement and metastatic disease whereas LVI showed weaker or no associations. Both BVI and LVI independently predicted regional lymph node metastases, LVI being the slightly stronger factor. BVI, not LVI predicted higher pathological stages. BVI showed reduced recurrence free (RFS) and disease specific (DSS) survival in uni-and multivariable analyses, whereas LVI did not. On HAS sections, VI was found in 31% of the cases. By IHC, 51% were positive, corresponding to a 64% increased sensitivity in detecting VI. VI assessed without IHC was significantly associated with RFS and DSS in univariable but not multivariable analysis. CONCLUSIONS: Our findings indicate that BVI is strongly associated with more aggressive tumor features. BVI was an independent prognostic factor in contrast to LVI. Furthermore, IHC increases VI sensitivity compared to HAS.

A preliminary study investigating the detection of lymphovascular invasion in germ cell tumors of the testis with double staining for OCT4/CD34.

Lymphovascular invasion (LVI) is a relevant prognostic factor in germ cell tumors of the testis (GCTT) and it has been included in the AJCC staging system. Nevertheless, its histological assessment is challenging, with low/moderate interobserver agreement also among expert uropathologists. Few studies focused on the potential role of immunohistochemistry to solve this critical issue; as result, in current guidelines there is no indication for additional staining to detect this histological feature. In the present study, we investigated the detection of LVI invasion in a small cohort of GCTT with double staining for OCT4/CD34. Although our results need to be validated in larger case series with follow-up data, they suggest as OCT4/CD34 could be a useful tool for the histological assessment of these tumors, helping to identify some histological mimickers of LVI and modifying the pT/stage in a significant percentage of patients.

Absence of lymphatic vessels in non-functioning bleb capsules of glaucoma drainage devices.

PURPOSE: To evaluate the presence and appearance of blood and lymphatic vessels in non-functioning bleb capsules of glaucoma drainage devices (GDD). MATERIALS AND METHODS: Non-functioning (n=14) GDD-bleb capsules of 12 patients were analyzed by immunohistochemistry for blood vessels (CD31, vascular endothelium), lymphatic vessels (lymphatic vessel endothelial hyaluronan receptor-1 [LYVE-1] and podoplanin) and macrophages (CD68). RESULTS: CD31+++ blood vessels and CD68+ macrophages were detected in the outer layer of all specimens. LYVE-1 immunoreactivity was registered in single non-endothelial cells in 8 out of 14 (57%) bleb capsule specimens. Podoplanin-immunoreactivity was detected in all cases, located in cells and profiles of the collagen tissue network of the outer and/or the inner capsule layer. However, a colocalization of LYVE-1 and podoplanin as evidence for lymphatic vessels was not detected. CONCLUSIONS: We demonstrate the presence of blood-vessels but absence of lymphatic vessels in non-functioning bleb capsules after GDD-implantation. While the absence of lymphatic vessels might indicate a possible reason for drainage device failure, this needs to be confirmed in upcoming studies, including animal experiments.

Morphological hallmarks facilitating distinction of omental milky spots and lymph nodes: an exploratory study on their discriminative capacity.

BACKGROUND: Omental milky spots (OMSs) are the primary lymphoid structures of the greater omentum. However, the presence of lymph nodes (LNs) has occasionally been mentioned as well. Understanding which lymphoid structures are present is of significance, especially in gastric tumor metastasis; tumor deposits in omental LNs suggest local lymphatic spread, whereas tumor deposits in OMSs suggest peritoneal spread and hence extensive disease. Since LNs and OMSs share morphological characteristics and OMSs might be wrongly identified as LNs, reliable hallmarks facilitating easy discrimination are needed. MATERIALS AND METHOD: A series of microscopic morphological hallmarks unique to LNs were selected as potential candidates and were assessed for their discriminative capacity: 1) capsule, 2) trabeculae, 3) subcapsular sinus, 4) afferent lymphatic vessels, 5) distinct B- and T cell regions, and 6) a layered organization with, from the outside in a capsule, cortex, paracortex, and medulla. These hallmarks were visualized by multiple staining techniques. RESULTS: Hallmarks 1, 2 5 and 6 were shown to be the most efficient as these were consistent and discriminative. They were best visualized by Picrosirius red, smooth muscle actin and a B-cell / T-cell double staining. CONCLUSION: The presence of a capsule, trabeculae, distinct B- and T-cell regions and a layered organization represent consistent and reliable morphological features which allow to easily distinguish LNs from OMSs, especially when applied in combination.

Absence of lymphatic vessels in term placenta.

BACKGROUND: There has been debate about the existence of lymphatic vessels in placenta. Lymphatic endothelial cell (LEC) markers such as LYVE-1 and podoplanin/D2-40 have been found, although PROX1 has not been detected. The most reliable marker for LECs is the double staining for CD31 and PROX1, which has not been performed yet. METHODS: We studied three term placentas and dissected them into three areas: i.) basal plate area, ii.) intermediate area, and iii.) chorionic plate area. We used immunofluorescence single and double staining with antibodies against CD31, PROX1, LYVE-1, VEGFR-3, D2-40/PDPN, CD34, CCBE-1, and vimentin, as well as nested PCR, qPCR, Western blot and transmission electron microscopy (TEM). RESULTS: At TEM level we observed structures that have previously mistakenly been interpreted as lymphatics, however, we did not find any CD31/PROX1 double-positive cells in placenta. Absence of PROX1 was also noted by nested PCR, qPCR and Western blot. Also, LEC marker VEGFR-3 was expressed only in a small number of scattered leukocytes but was absent from vessels. The LEC marker D2-40/PDPN was expressed in most stromal cells, and the LEC marker LYVE-1 was found in a considerable number of stromal cells, but not in endothelial cells, which were positive for CD31, CD34, CCBE-1 and vimentin. Additionally, vimentin was found in stromal cells. CONCLUSIONS: Our studies clearly show absence of lymphatics in term placenta. We also show that the functional area of the mother's endometrium is not penetrated by lymphatics in term pregnancy.

Integrin ß4 Is an Effective and Efficient Marker in Synchronously Highlighting Lymphatic and Blood Vascular Invasion, and Perineural Aggression in Malignancy.

Lymphovascular invasion (LVI) and perineural invasion (PNI) are 2 important pathologic parameters and need to be accurately assessed in multiple malignancies. Integrin ß4, a member of the integrin family, has been reported to be positively expressed in vascular endothelia, peripheral nerves, and a collection of epithelia. However, little is known about the effectiveness of ß4 immunostaining on the recognition of LVI and PNI. Herein, we explored the applicability of ß4 immunostaining in stomach, thyroid, and breast cancers. Parallel immunostaining of D2-40, CD34, and S-100 was performed as controls for lymphatic endothelia, vascular endothelia, and neural fibers, respectively. The results demonstrated that ß4 concurrently stained the lymphatic and vascular endothelia, and the peripheral nerves. Both LVI and PNI were clearly and accurately outlined by ß4 immunostaining. ß4 was also expressed in the majority of tumor cells, enabling recognition of LVI and PNI encroached by small tumor clusters. In contrast to D2-40 and CD34, ß4 staining was not observed in stromal cells, and therefore it facilitated differentiation between the shrinkage cleft and LVI. According to our results, ß4 staining strikingly increased the diagnostic accuracy and interobserver concordance for LVI and PNI compared with hematoxylin and eosin staining alone. Finally, the applicability of ß4 was confirmed in 9 other types of malignancies, including cancers of the colon, prostate, esophagus, lung, kidney, uterus, tongue, bladder, and liver. Collectively, ß4 is a reliable marker for synchronous detection and diagnosis of LVI and PNI.

Interobserver Agreement in Vascular Invasion Scoring and the Added Value of Immunohistochemistry for Vascular Markers to Predict Disease Relapse in Stage I Testicular Nonseminomas.

Vascular invasion has been identified as an informative risk factor for relapse in stage I testicular nonseminomas, used to tailor treatment. We investigated interobserver agreement in vascular invasion reporting and studied the potential additional value of immunohistochemistry for vascular markers for predicting relapse. Patients (n=52) with stage I testicular nonseminomas undergoing surveillance (1993-2006) were included (median follow-up of 66 mo). Two formalin-fixed paraffin-embedded blocks with >1 cm tissue and tumor/normal parenchyma interface were stained with hematoxylin and eosin and CD31, FVIII, and D2-40. Slides were assessed by 3 independent testicular germ cell tumor-dedicated pathologists, and agreement was assessed using Cohen κ statistic. Sensitivity, specificity, and accuracy of vascular invasion scoring in predicting relapse were calculated. Agreement among testicular germ cell tumor-dedicated pathologists was moderate (κ=0.49 to 0.54), as was performance in predicting disease relapse (particularly, specificity of 86%). Immunohistochemistry increased overall sensitivity (71%), but decreased specificity (71%) in predicting relapse. All patients (n=8) with both blood and lymphatic vascular invasion developed a relapse. In multivariable analysis (including age, tumor size, rete testis invasion, and serum tumor markers), only vascular invasion had an independent impact in predicting relapse. Assessment of vascular invasion by testicular germ cell tumor-dedicated pathologists is good and is clinically meaningful, predicting disease relapse. Immunohistochemistry for vascular markers improves sensitivity of detecting disease relapse and allows for the identification of high-risk patients with both blood and lymphatic vascular invasion simultaneously, potentially of interest for tailored chemotherapy.

[Changes of lymphatic vessel density in lung adenocarcinoma in situ, minimally invasive adenocarcinoma, and invasive adenocarcinoma and the regulatory factors].

OBJECTIVE: To analyze the changes in tumor lymphatic vessel density (LVD) in patients with lung adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IA) and explore the regulatory factors of LVD. METHODS: Complete clinicopathological data were collected form a total of 301 patients with lung adenocarcinoma, including 28 (9.3%) with AIS, 86 (28.6%) with MIA, and 187 (62.1%) with IA. The LVD of all the adenocarcinomas were calculated after D2-40 immunohistochemical staining, and MT1-MMP and VEGF-C expression levels were also evaluated. The differences in LVD among the groups and the correlations of tumor LVD with the expressions of MT1-MMP and VEGF-C and the clinicopathological factors were analyzed. RESULTS: The LVD differed significantly among AIS, MIA, and IA groups (P= 0.000). The LVDs was significantly correlated with the level of VEGF-C protein expression (r=0.917, P=0.009), tumor size (r= 0.686, P=0.017), lymph node metastasis (r=0.739, P=0.000), and clinical stage (r=0.874, P=0.012) of the patients. CONCLUSIONS: Tumor lymphangiogenesis plays an important role in lung adenocarcinoma progression, and VEGF-C may promote this process.

Oral Nanoparticles Exhibit Specific High-Efficiency Intestinal Uptake and Lymphatic Transport.

Herein, we describe a simple and promising nanoparticle oral delivery phenomenon and propose pathways for oral nanoparticle absorption from the gastrointestinal tract (GIT), combining apical sodium-dependent bile acid transporter-mediated cellular uptake and chylomicron transport pathways. This strategy is proven to employ bile-acid-conjugated, solid fluorescent probe nanoparticles (100 nm diameter) to exclude any potential artifacts and instability issues in observing transport pathways and measuring oral bioavailability. The results of the in vitro studies showed that there is no interference from bile acid and no simultaneous uptake of nanoparticles and dextran. The probe nanoparticle exhibited a significantly enhanced average oral bioavailability (47%) with sustained absorption in rats. Particle-size- and dose-dependent oral bioavailability was observed for oral nanoparticle dosing up to 20 mg/kg. The probe nanoparticles appear to be transported to systemic circulation via the gut lymphatic system. Thus, we propose a pathway for oral nanoparticle absorption from the GIT, combining apical bile acid transporter-mediated cellular uptake and chylomicron transport pathways.

Histomorphometric evaluation of the Ki-67 proliferation rate and CD34 microvascular and D2-40 lymphovascular densities drives the pulmonary typical carcinoid outcome.

Ki-67 has shown promise as a prognostic factor in pulmonary carcinoids. In this study, we sought to validate the importance of Ki-67 and study the relationships between Ki-67 and other stromal biomarkers of vascular density. We examined Ki-67, CD34, and D2-40 in tumor tissues from 128 patients with surgically excised typical carcinoid of the lung. We used immunohistochemistry and morphometry to evaluate the amount of tumor staining for cellular proliferation (Ki-67), microvascular density (CD34-MVD), and D2-40 lymphovascular density. The main outcome was overall survival, considered as life expectancy until death from metastasis. Specimens from patients with central tumors showed high CD34-MVD (P = .01), which was also significantly associated with a compromised surgical margin, lymph node metastasis, and clinical stage Ib. Equally significant was high D2-40 lymphovascular density in central specimens with a compromised surgical margin and lymph node metastasis. A high Ki-67 proliferation rate was significantly associated with tumors from patients with clinical stage IIb, IIIa, and IV disease. Multivariate Cox model analysis demonstrated that tumor location and stage, surgical margin, tumor size, and N stage were significantly related to survival time (P < .05). Quantitative staining of the tumor for Ki-67 and CD34-MVD served as prognostic factors (P < .05), which were more relevant than the surgical and pathological stage. Ki-67 greater than 5% and CD34-MVD greater than 7% staining comprise a subset of patients with higher death hazard; this outcome may harbor evidence for further prospective studies of target therapy after surgical resection.

Marked Prognostic Impact of Minimal Lymphatic Tumor Spread in Prostate Cancer.

BACKGROUND: Nodal metastasis (N1) is a strong prognostic parameter in prostate cancer; however, lymph node evaluation is always incomplete. OBJECTIVE: To study the prognostic value of lymphatic invasion (L1) and whether it might complement or even replace lymph node analysis in clinical practice. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of pathological and clinical data from 14 528 consecutive patients. INTERVENTION: Radical prostatectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The impact of L1 and N1 on patient prognosis was measured with time to biochemical recurrence as the primary endpoint. RESULTS AND LIMITATIONS: Nodal metastases were found in 1602 (12%) of 13 070 patients with lymph node dissection. L1 was seen in 2027 of 14 528 patients (14%) for whom lymphatic vessels had been visualized by immunohistochemistry. N1 and L1 continuously increased with unfavorable Gleason grade, advanced pT stage, and preoperative prostate-specific antigen (PSA) values (p<0.0001 each). N1 was found in 4.3% of 12 501 L0 and in 41% of 2027 L1 carcinomas (p<0.0001). L1 was seen in 11% of 9868 N0 and in 61% of 1360 N1 carcinomas (p<0.0001). Both N1 and L1 were linked to PSA recurrence (p<0.0001 each). This was also true for 17 patients with isolated tumor cells (ie, <200 unequivocal cancer cells without invasive growth) and 193 metastases ≤1mm. Combined analysis of N and L status showed that L1 had no prognostic effect in N1 patients but L1 was strikingly linked to PSA recurrence in N0 patients. N0L1 patients showed a similar outcome as N1 patients. CONCLUSIONS: Analysis of lymphatic invasion provides comparable prognostic information than lymph node analysis. Even minimal involvement of the lymphatic system has pivotal prognostic impact in prostate cancer. Thus, a thorough search for lymphatic involvement helps to identify more patients with an increased risk for disease recurrence. PATIENT SUMMARY: Already minimal amounts of tumor cells inside the lymph nodes or intraprostatic lymphatic vessels have a severe impact on patient prognosis.

Intralymphatic Spread is a Rare Finding Associated With Poor Prognosis in Diffuse Large B-Cell Lymphoma With Extranodal Involvements.

Intralymphatic spread is common in solid cancers, but has been rarely studied in lymphomas. Review of 635 extranodal specimens from 475 diffuse large B-cell lymphoma (DLBCL) patients revealed intralymphatic spread in 10 surgical resection specimens from 10 patients including 9 de novo DLBCLs and 1 Richter transformation. The prevalence in de novo DLBCL with extranodal involvements was 1.65%. The most common involved site of intralymphatic spread was the gastrointestinal tract, followed by the female genital tract and breasts. Lymphatic vessels, lined by D2-40-positive endothelial cells, were expanded by lymphoma cells, reminiscent of intravascular lymphoma or tumor emboli. None of the involved lymphatic vessels were located in the mucosa. Patients with intralymphatic spread had a trend of lower overall response rate and a trend of higher progressive disease than those without intralymphatic spread. Compared with patients without intralymphatic spread, those patients with intralymphatic spread had a shorter median overall survival (14.3 vs. 96.2 mo; P=0.004) and a shorter median progression-free survival (11.2 vs. 64.2 mo; P=0.01), respectively. Multivariate analyses showed that intralymphatic spread was an independent poor prognostic factor for overall survival (hazard ratio, 3.029; 95% confidence interval, 1.315-6.978; P=0.009), irrespective of the National Comprehensive Cancer Network-International Prognostic Index, B symptoms, and serum albumin levels. Among patients who underwent surgical resection, intralymphatic spread was still an independent prognostic factor. In conclusion, our study demonstrated extranodal intralymphatic spread in DLBCL. Inspiringly, this rare morphologic finding may serve as a new negative prognostic indicator in DLBCL with extranodal involvements.

In Vivo Molecular Optical Coherence Tomography of Lymphatic Vessel Endothelial Hyaluronan Receptors.

Optical Coherence Tomography (OCT) imaging of living subjects offers increased depth of penetration while maintaining high spatial resolution when compared to other optical microscopy techniques. However, since most protein biomarkers do not exhibit inherent contrast detectable by OCT, exogenous contrast agents must be employed for imaging specific cellular biomarkers of interest. While a number of OCT contrast agents have been previously studied, demonstrations of molecular targeting with such agents in live animals have been historically challenging and notably limited in success. Here we demonstrate for the first time that microbeads (µBs) can be used as contrast agents to target cellular biomarkers in lymphatic vessels and can be detected by OCT using a phase variance algorithm. This molecular OCT method enables in vivo imaging of the expression profiles of lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1), a biomarker that plays crucial roles in inflammation and tumor metastasis. In vivo OCT imaging of LVYE-1 showed that the biomarker was significantly down-regulated during inflammation induced by acute contact hypersensitivity (CHS). Our work demonstrated a powerful molecular imaging tool that can be used for high resolution studies of lymphatic function and dynamics in models of inflammation, tumor development, and other lymphatic diseases.

Fluid shear stress activates YAP1 to promote cancer cell motility.

Mechanical stress is pervasive in egress routes of malignancy, yet the intrinsic effects of force on tumour cells remain poorly understood. Here, we demonstrate that frictional force characteristic of flow in the lymphatics stimulates YAP1 to drive cancer cell migration; whereas intensities of fluid wall shear stress (WSS) typical of venous or arterial flow inhibit taxis. YAP1, but not TAZ, is strictly required for WSS-enhanced cell movement, as blockade of YAP1, TEAD1-4 or the YAP1-TEAD interaction reduces cellular velocity to levels observed without flow. Silencing of TEAD phenocopies loss of YAP1, implicating transcriptional transactivation function in mediating force-enhanced cell migration. WSS dictates expression of a network of YAP1 effectors with executive roles in invasion, chemotaxis and adhesion downstream of the ROCK-LIMK-cofilin signalling axis. Altogether, these data implicate YAP1 as a fluid mechanosensor that functions to regulate genes that promote metastasis.

A Three-Dimensional Lymphatic Endothelial Cell Tube Formation Assay to Identify Novel Kinases Involved in Lymphatic Vessel Remodeling.

The lymphatic system is a series of vessels that transport cells and excess fluid from tissues to the blood vascular system. Normally quiescent, the lymphatics can grow or remodel in response to developmental, immunological, or cells pathological stimuli. Lymphatic vessels comprise lymphatic endothelial cells (LECs) that can respond to external growth factors by undergoing proliferation, migration, adhesion, and tube and lumen formation into new vessel structures, a process known as lymphangiogenesis. To understand the key gene and signaling pathways necessary for lymphangiogenesis and lymphatic vessel remodeling, we have developed a three-dimensional LEC tube formation assay to explore the role of kinase signaling in these processes. The collagen-overlay-based assay was used with primary human adult dermal LECs to investigate a library of 60 tyrosine kinase (TK) and TK-like genes by siRNA knockdown. Nine candidate genes were identified and characterized for their ability to modify key parameters of lymphatic tube formation, including tube length, area, thickness, branching, and number of blind-ended sacs. Four genes-ZAP70, IRAK4, RIPK1, and RIPK2-were identified as high-confidence hits after tertiary deconvolution screens and demonstrate the utility of the assay to define LEC genes critical for the formation of tube structures. This assay facilitates the identification of potential molecular targets for novel drugs designed to modulate the remodeling of lymphatics that is important for the metastatic spread of cancer and other pathologies.

Differentiating Intralymphatic Histiocytosis, Intravascular Histiocytosis, and Subtypes of Reactive Angioendotheliomatosis: Review of Clinical and Histologic Features of All Cases Reported to Date.

Reactive angioendotheliomatosis (REA) is a rare benign angioproliferative condition of the skin, which has been noted to occur in patients with a variety of underlying systemic diseases. Histopathologically, this condition is characterized by vascular proliferation, and endothelial cell hyperplasia within the lumina and around dermal vessels, without significant cellular atypia. Since the first case of RAE was reported in 1958, multiple histologic patterns of benign cutaneous vascular proliferations with similar clinical presentations to RAE have been described in the literature and have been proposed as subtypes of the originally described condition. Among these entities are diffuse dermal angiomatosis (DDA), acroangiodermatitis, glomeruloid angioendotheliomatosis, and angiomatosis associated with cryoproteins. It has also been proposed that another entity, characterized by the benign proliferation of histiocytes within the lumina of cutaneous vessels, is a subtype of RAE. Histiocytosis within dermal vessels, in conjunction with skin pathology, was first reported in 1994. Based on the appearance of involved vessels, it was initially believed that the histiocytic proliferations were within the lumina of capillaries. Hence, the term intravascular histiocytosis was introduced to describe this histologic finding. However, subsequent introduction of an immunohistochemical (IHC) marker specific for lymphatic vessels demonstrated that most cases of cutaneous histiocyte proliferation are intralymphatic, rather than truly intravascular. However, there have also been reports of IHC-confirmed cases of true intravascular (intracapillary) histiocytosis. In this study, clinical and histologic data from all of the cases of RAE and IHC-confirmed cases of intravascular histiocytosis and intralymphatic histiocytosis reported in the literature to date are examined. Through comparison of the frequency with which key clinical and histologic features present in cases of each group, the authors provide improved clarity of the similarities and differences between these 3 entities.

The potential role of perivascular lymphatic vessels in preservation of kidney allograft function.

BACKGROUND: Lymphangiogenesis occurs in diseased native kidneys and kidney allografts, and correlates with histological injury; however, the clinical significance of lymphatic vessels in kidney allografts is unclear. METHODS: This study retrospectively reviewed 63 kidney transplant patients who underwent protocol biopsies. Lymphatic vessels were identified by immunohistochemical staining for podoplanin, and were classified according to their location as perivascular or interstitial lymphatic vessels. The associations between perivascular lymphatic density and kidney allograft function and pathological findings were analyzed. RESULTS: There were no significant differences in perivascular lymphatic densities in kidney allograft biopsy specimens obtained at 0 h, 3 months and 12 months. The groups with higher perivascular lymphatic density showed a lower proportion of progression of interstitial fibrosis/tubular atrophy grade from 3 to 12 months (P for trend = 0.039). Perivascular lymphatic density was significantly associated with annual decline of estimated glomerular filtration rate after 12 months (r = -0.31, P = 0.017), even after adjusting for multiple confounders (standardized ß = -0.30, P = 0.019). CONCLUSIONS: High perivascular lymphatic density is associated with favourable kidney allograft function. The perivascular lymphatic network may be involved in inhibition of allograft fibrosis and stabilization of graft function.

Lymphovascular invasion in more than one-quarter of small rectal neuroendocrine tumors.

AIM: To identify the frequency, clinicopathological risk factors, and prognostic significance of lymphovascular invasion (LVI) in endoscopically resected small rectal neuroendocrine tumors (NETs). METHODS: Between June 2005 and December 2015, 104 cases of endoscopically resected small (≤ 1 cm) rectal NET specimens at Hallym University Sacred Heart Hospital in Korea were retrospectively evaluated. We compared the detected rate of LVI in small rectal NET specimens by two methods: hematoxylin and eosin (H&E) and ancillary immunohistochemical staining (D2-40 and Elastica van Gieson); in addition, LVI detection rate difference between endoscopic procedures were also evaluated. Patient characteristics, prognosis and endoscopic resection results were reviewed by medical charts. RESULTS: We observed LVI rates of 25.0% and 27.9% through H&E and ancillary immunohistochemical staining. The concordance rate between H&E and ancillary studies was 81.7% for detection of LVI, which showed statistically strong agreement between two methods (κ = 0.531, P < 0.001). Two endoscopic methods were studied, including endoscopic submucosal resection with a ligation device and endoscopic submucosal dissection, and no statistically significant difference in the LVI detection rate was detected between the two (26.3% and 26.8%, P = 0.955). LVI was associated with large tumor size (> 5 mm, P = 0.007), tumor grade 2 (P = 0.006). Among those factors, tumor grade 2 was the only independent predictive factor for the presence of LVI (HR = 4.195, 95%CI: 1.321-12.692, P = 0.015). No recurrence was observed over 28.8 mo regardless of the presence of LVI. CONCLUSION: LVI may be present in a high percentage of small rectal NETs, which may not be associated with short-term prognosis.

Lymphovascular infiltration in the tumor bed is a useful marker of biological behavior in breast cancer.

PURPOSE: Tumor cells can metastasize by entering existing vessels or new vessels actively recruited into the primary tumor. Invasion of the lymphatics and blood vessels in the periphery of the tumor seems to be a prerequisite step in the metastatic process. The aim of this study was to correlate peripheral lymphatic vessel infiltration (PLI) and peripheral blood vessel infiltration (PVI) in a cohort of patients with invasive ductal carcinoma of the breast with various other prognostic parameters and outcome. METHODS: The study population consisted of 236 female patients with invasive ductal breast carcinomas, who had been operated between 2011 and 2013. The registered data included age at diagnosis, histological subtype, tumor size, TNM stage, histological grade, estrogen (ER) and progesterone receptors (PR), HER-2, p53, and PLI and PVI. RESULTS: Pathological examination revealed that 22.5% of the patients had PVI and 37.3% had PLI at the tumor front. PVI correlated with younger age (p<0.05), higher histologic grade (p<0.05), advanced TNM stage (p<0.05), higher T stage (p<0.05), higher N stage (p<0.05) and positive Ki67 expression (p<0.05). Similarly, PLI correlated with higher histologic grade (p<0.05), advanced TNM stage (p<0.05), higher T stage (p<0.05) and higher N stage (p<0.05). Statistical analysis did not reveal significant correlation between the presence of tumor blood and lymphatic vessels with infiltration in overall (OS) and disease-free survival (DFS). CONCLUSIONS: PLI and PVI are important markers of worse clinical outcome as shown by their association with other established factors, but no association with recurrence and survival could be proven.