Different immunoreactivity of endothelial markers in well and poorly differentiated areas of angiosarcomas

Spontaneous abdominal hemangiosarcoma in a ferret

Herein, we describe the case of a 6-year-old female ferret that died within a few days of the onset of anorexia and reduced spontaneous locomotor activity. Necropsy revealed a dark red abdominal mass of unknown origin between the right lobes of the pancreas and the proximal jejunum, with massive blood retention in the peritoneal cavity. Histopathologically, spindle-shaped or sometimes polygonal tumor cells were proliferating with irregularly shaped vascular spaces containing blood components and surrounding-tissue infiltration. In some areas, tumor cells formed distinctly dilated blood vessel-like structures. Immunohistochemically, most of the tumor cells were strongly positive for CD31, but factor VIII-related antigen immunoreactivity was confined to the area with dilated blood vessel-like structures. Based on these findings, the tumor was diagnosed as an abdominal hemangiosarcoma. Abdominal hemangiosarcoma excluding cases of the liver and spleen are rare in ferrets.

Value of contrast-enhanced ultrasound for detection of synovial vascularity in experimental rheumatoid arthritis: an exploratory study

Objective

This study aimed to examine the associations between contrast-enhanced ultrasound (CEUS) imaging and synovial hypervascularity and synovitis score in a rabbit model of antigen-induced arthritis (AIA), compared with power Doppler ultrasound (PDUS).

Methods

We investigated 50 knee joints in 25 AIA rabbits (AIA group), and 10 knee joints in five sham-injected rabbits (control group). PDUS and CEUS images were evaluated at the 8th week. Ultrasound-guided synovial biopsies were targeted in the area with hypervascularity, and synovial microvessel density (MVD) was evaluated by immunohistochemical staining of CD31.

Results

The PDUS score was significantly higher in the AIA group (2.61 ± 0.78) compared with the control group (0.50 ± 0.53). CEUS in the AIA group revealed a fast-in/slow-out pattern of contrast enhancement. MVD revealed by CD31+ vessel count and the synovitis score were significantly higher in the AIA group compared with the control group. In the AIA group, CEUS findings showed a better correlation with MVD revealed by CD31+ and synovitis score than PDUS findings.

Conclusion

CEUS is superior to PDUS for estimating synovial hypervascularity and hyperplasia in experimental rheumatoid arthritis.

Outlasting a Rare Duodenal Angiosarcoma

With current life expectancies exceeding 78 years on average, to be confronted with the discovery of a rare cancer often found in advanced stages is a startling devastation. Angiosarcoma of the intestine is a rare and aggressive tumor that is not often considered in the differential diagnosis of intestinal obstruction. Once found and accurately diagnosed, it is a bewildering race against time as its median survival time is 150 days from diagnosis. This case report details a rare small intestinal angiosarcoma with its host surpassing current epidemiological standards of survival time despite only being eligible for chemotherapy.

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

Background

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.

Methods

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.

Results

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.

Conclusions

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.

Primary Small Intestinal Angiosarcoma: Epidemiology, Diagnosis and Treatment

Angiosarcoma is an aggressive mesenchymal sarcoma of endothelial cell origin with high mortality. Its occurrence in the small intestine is exceedingly low. In addition to the rarity of small intestine angiosarcoma, the nonspecific early clinical symptoms obscure the suspicion of such tumors and thereby delay the diagnosis. In a hope to improve the knowledge of this rare but fatal neoplasm, we report one case of angiosarcoma of duodenum and jejunum in a 73-year-old man. Furthermore, we summarize and analyze the common clinical features, tumor markers, treatment, and survival of previous reported cases of this malignancy. Small bowel angiosarcoma occurs more often in men than women (1.6:1). The median age at diagnosis is 68.5 years. The overall median survival time is 150 days; the median survival time in female (300 days) is longer than that of male patients (120 days). Von Willebrand factor (vWF), CD31, CD34, vimentin, and Ulex europaeus agglutinin 1 appear to be the most useful markers for the diagnosis. The majority of the patients underwent surgical resection alone or surgery with subsequent chemotherapy. The patients treated with surgery plus chemotherapy survive longer than those underwent surgical resection only (median 420 days, n = 7 vs. 96.5 days, n = 26, respectively; P = 0.0275). Further studies of more cases are needed for a better understanding of this rare entity, as well as the development of effective strategies for prevention, early diagnosis, and treatment.

Differential effects of recombinant human endostatin treatment on differentiated and undifferentiated blood vessels in Lewis lung cancer

In the present study, we evaluated the effects of recombinant human (rh-)endostatin treatment on differentiated and undifferentiated tumor vasculature in Lewis lung cancer for the first time. Lewis lung carcinoma models were established. The animals were treated daily with varying doses of rh-endostatin or physiological saline for 14 days. Intravital microscopy was performed following treatment. The expression of CD31 and CD34 was determined by immunohistochemical staining, and microvessel density (MVD) was determined. Rh-endostatin treatment significantly decreased the tumor volume compared with the control group. Rh-endostatin treatment normalized the architecture of the vascular network. CD31⁺ cells decreased following rh-endostatin treatment, whereas CD34⁺ cells were unaffected by the treatment. Accordingly, the MVD value of CD31⁺ cells in rh-endostatin treatment groups significantly decreased (P<0.01), and the MVD value of CD34⁺ cells in the rh-endostatin treatment groups did not decrease. Undifferentiated tumor blood vessels were significantly inhibited by rh-endostatin treatment. In conclusion, the normalization of the tumor vasculature by endostatin may be related to the differential effects of endostatin on differentiated and undifferentiated blood vessels.

Constitutive phosphorylation of the mTORC2/Akt/4E-BP1 pathway in newly derived canine hemangiosarcoma cell lines

BACKGROUND

Canine hemangiosarcoma (HSA) is a malignant tumor with poor long-term prognosis due to development of metastasis despite aggressive treatment. The phosphatidyl-inositol-3 kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway is involved in its endothelial pathologies; however, it remains unknown how this pathway plays a role in canine HSA. Here, we characterized new canine HSA cell lines derived from nude mice-xenografted canine HSAs and investigated the deregulation of the signaling pathways in these cell lines.

RESULTS

Seven canine HSA cell lines were established from 3 xenograft canine HSAs and showed characteristics of endothelial cells (ECs), that is, uptake of acetylated low-density lipoprotein and expression of canine-specific CD31 mRNA. They showed varied morphologies and mRNA expression levels for VEGF-A, bFGF, HGF, IGF-I, EGF, PDGF-B, and their receptors. Cell proliferation was stimulated by these growth factors and fetal bovine serum (FBS) in 1 cell line and by FBS alone in 3 cell lines. However, cell proliferation was not stimulated by growth factors and FBS in the remaining 3 cell lines. Phosphorylated p44/42 Erk1/2 was increased by FBS stimulation in 4 cell lines. In contrast, phosphorylation of Akt at Ser473, mTOR complex 1 (mTORC1) at Ser2448, and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) at Ser65 was high in serum-starved condition and not altered by FBS stimulation in 6 cell lines, despite increased phosphorylation of these residues in normal canine ECs. This suggested that the mTORC2/Akt/4E-BP1 pathway was constitutively activated in these 6 canine HSA cell lines. After cell inoculation into nude mice, canine HSA tumors were formed from 4 cell lines and showed Akt and 4E-BP1 phosphorylation identical to the parental cell lines.

CONCLUSIONS

Our findings suggest that the present cell lines may be useful tools for investigating the role of the mTORC2/Akt/4E-BP1 pathway in canine HSA formation both in vivo and in vitro.

Morphologic classification of microvessels in hepatocellular carcinoma is associated with the prognosis after resection

BACKGROUND AND AIM

The relationship between neovasculature in hepatocellular carcinoma (HCC) and the prognosis of patients still remains controversial. The aim of the present study was to investigate the prognostic significance of morphologic features of the microvessels in patients with HCC after resection.

METHODS

The paraffin-embedding specimens of 98 consecutive HCC patients, who received primary resection between 2000 and 2002, were collected from our prospective established tumor bank. The intratumoral microvessels were evaluated by immunohistochemical staining for CD31 and CD34. The disease-free survival (DFS) and overall survival (OS) of patients were analyzed by Kaplan-Meier analysis and Cox proportional hazards regression model.

RESULTS

There are two distinct microvessel types: capillary-like and sinusoid-like were identified in tumor tissues. The patients could be divided into two groups according to their microvessel types. Both DFS and OS of capillary group patients (n = 65) were better than those of sinusoid group patients (n = 33). Multivariate analyses showed that the microvessel type was an independent risk factor for DFS (P = 0.016) and OS (P = 0.004) of this cohort. Capillary-like microvessels were more common in small HCC, and were significantly associated with higher microvessel density, while sinusoid-like microvessels were significantly correlated with lower microvessel density.

CONCLUSIONS

The results of our study suggested that the microvessel type is an effective predictor of survival in patients with HCC after resection, which might serve as potential novel therapeutic targets for prevention of the recurrence of HCC after resection.

The transcription factor LMO2 is a robust marker of vascular endothelium and vascular neoplasms and selected other entities

The transcription factor LMO2 is involved in vascular and hematopoietic development and hematolymphoid neoplasia. We have demonstrated that LMO2 is expressed nearly ubiquitously in native and neoplastic vasculature, including lymphatics. LMO2 reactivity is otherwise virtually absent in nonhematolymphoid tissues except in breast myoepithelium, prostatic basal cells, and secretory phase endometrial glands. Vasculature is LMO2- in adult and fetal heart, brain of older adults, hepatic sinusoids, and hepatocellular carcinoma. LMO2 is uniformly expressed in benign vascular and lymphatic neoplasms and in most malignant vascular neoplasms with the exception of epithelioid vascular neoplasms of pleura and bone. Among nonvascular neoplasms, LMO2 reactivity is present in giant cell tumor of tendon sheath, juvenile xanthogranuloma, a subset of gastrointestinal stromal tumors, small round blue cell tumors, and myoepithelial-derived neoplasms. The restricted expression pattern, nuclear localization, and crisp staining of LMO2 in paraffin blocks make it an attractive candidate for the diagnostic immunohistochemistry laboratory.

Sphingosine-1-phosphate receptor 1 is a useful adjunct for distinguishing vascular neoplasms from morphological mimics

Sphingosine-1-phosphate receptor 1 (S1P(1)) has been shown to play an important role in the migration, proliferation, and survival of endothelial cells. S1P(1) of vascular and lymphatic endothelial cells can be detected by immunostaining of paraffin-embedded sections using a rabbit anti-S1P(1) antibody. In this study, to distinguish vascular tumors from histologic mimics using immunohistochemical means, we evaluated the expression of S1P(1) in a range of vascular tumors. S1P(1) expression was observed in eight of eight hemangiomas, four of four lymphangiomas, four of four epithelioid hemangioendotheliomas, three of three Kaposi's sarcomas, and 15 of 15 angiosarcomas with vasoformative, spindle, epithelioid, and undifferentiated features. Conventional analysis and use of a tissue microarray of soft tissue tumors revealed three of 21 liposarcomas to have weak cytoplasmic staining and one of five squamous cell carcinomas to have membranous staining in a very limited area among 115 nonvascular tumors including histological mimics of angiosarcoma such as undifferentiated carcinoma, melanoma, and epithelioid sarcoma. The sensitivity with regards to the angiosarcoma cases was equal to, or even exceeded in undifferentiated angiosarcoma, that of CD31. Based on this study, S1P(1) may be a useful adjunct to CD31 in cases where a vascular neoplasm requires a differential diagnosis.

Lymphangiosarcoma in a cat

This report describes a 5-year-old female cat with lymphangiosarcoma arising within the dermis and subcutis of the caudal mammary region. The mass presented as a large, poorly demarcated and fluctuant swelling with bruising of the overlying skin. Histopathologically, the dermis and subcutis in the affected region were diffusely oedematous, haemorrhagic, and infiltrated by plump spindle cells that formed irregular vascular clefts and cavernous channels. Neoplastic cells were aligned in one or more layers along oedematous collagenous trabeculae. The vascular clefts and channels contained only a few or no erythrocytes. The neoplastic cells had moderate to marked nuclear pleomorphism and prominent nucleoli. Lymphocytes and plasma cells were scattered throughout the neoplasm and the adjacent soft tissues. Immunohistochemical labelling revealed the neoplastic cells to express vimentin, factor VIII-related antigen and the lymphatic endothelial cell marker PROX-1, but the cells did not express cytokeratin. The nuclei of many neoplastic cells expressed the proliferation marker Ki67. These histopathological and immunohistochemical findings confirmed the diagnosis of lymphangiosarcoma. This is the first report describing the usefulness of expression of PROX-1 for differentiating between angiosarcoma of lymphatic and vascular origin in cats.

Two distinct types of blood vessels in clear cell renal cell carcinoma have contrasting prognostic implications

PURPOSE

Intratumoral microvascular density (MVD) has been controversial as an indicator of prognosis in clear cell renal cell carcinoma (CCRCC). Classification of the intratumoral blood vessels based on differential expressions of blood vessel markers has not been correlated with patient prognosis in CCRCC. In this study, we aimed to evaluate the association of different categories of blood vessels with the patients' outcomes.

EXPERIMENTAL DESIGN

Seventy-eight CCRCC patients who underwent nephrectomy alone were enrolled. Paraffin-embedded CCRCC tissues, together with 16 nonmalignant kidney cortex tissues, were used in tissue microarray analyses and conventional section analyses. The characteristics of intratumoral blood vessels were identified by multiple blood vessel markers and pericyte markers. A computerized image analysis program was used to quantitatively calculate the vascular density.

RESULTS

Two distinct types of microvessels were identified in CCRCC: undifferentiated (CD31(+)/CD34(-)) and differentiated (CD34(+)) vessels. A higher undifferentiated MVD significantly correlated with higher tumor grades and shorter patient survival. In contrast, a higher differentiated MVD significantly correlated with lower tumor grade and longer survival. Multivariate analyses showed that undifferentiated MVD was an independent prognostic factor for patient survival. An inverse correlation between undifferentiated MVD and differentiated MVD was also identified in CCRCC.

CONCLUSIONS

This is the first report showing distinct types of vasculature in CCRCC correlated with contrasting prognoses. A refined classification of CCRCC based on vasculature is therefore important for evaluating prognosis, and it may also have therapeutic implications.

Angiosarcoma in a chronically immunosuppressed renal transplant recipient: report of a case and review of the literature

Angiosarcomas are rare malignant tumors of endothelial origin that occur predominantly in the adult population. To date, only 12 cases have been described after renal transplantation. We review the literature and present an additional case of a 59-year-old patient in whom lower-extremity lesions of cutaneous angiosarcoma developed several years after transplantation. Of the 13 patients, clinical details were available in only 12 cases. There were 10 male and 2 female patients. The mean age at diagnosis was 47.6 years (age range, 28-71 years). Almost all patients were on a combination immunosuppressive regimen, and the interval between transplantation and the development of the tumor was variable in the range of 8 months to 12 years. In five patients, the tumor arose within or adjacent to an arteriovenous fistula site. Cutaneous involvement was observed in only four cases. The histologic spectrum consisted of both well-differentiated and poorly differentiated tumors. In one patient, features of the hemophagocytic syndrome were clinically present and the tumor morphologically displayed prominent erythrophagocytosis. In two of the cases, including the patient described in the current report, polymerase chain reaction was performed on lesional tissue for human herpesvirus-8 and the result was negative for the presence of viral DNA. Despite the use of multimodal aggressive therapy in most patients, death as a result of disease dissemination occurred over variable time periods (range, 1-15 months).

Cutaneous vascular proliferations. Part III. Malignant neoplasms, other cutaneous neoplasms with significant vascular component, and disorders erroneously considered as vascular neoplasms

In this third and last part of our review of cutaneous vascular proliferations we include malignant vascular neoplasms and a group of heterogeneous cutaneous neoplasms characterized by a significant vascular component. We also review some disorders that, in our opinion, have been erroneously considered as vascular neoplasms. We review the epidemiologic, histogenetic, clinical, and histopathologic aspects of Kaposi's sarcoma in its four distinctive variants (classic, African-endemic, immunosuppressive drug-associated, and AIDS-associated Kaposi's sarcoma). There is still controversy about whether Kaposi's sarcoma represents a reactive vascular proliferation or a true neoplastic proliferation. In any event, most authors believe that Kaposi's sarcoma does not produce metastatic disease, but rather develops in multifocal fashion. However, Kaposi's sarcoma may cause death, especially in immunosuppressed patients. Epithelioid hemangioendothelioma, Dabska's tumor, and retiform hemangioendothelioma are examples of low-grade angiosarcoma. In contrast, cutaneous angiosarcomas, including the clinical variants of angiosarcoma of face and scalp in elderly patients, angiosarcoma associated with lymphedema, and radiation-induced angiosarcoma are highly aggressive neoplasms with poor prognosis and most patients die within a short period after presentation. A group of benign and relatively frequent cutaneous neoplasms, including multinucleate cell angiohistiocytoma, angiofibroma, angioleiomyoma, angiolipoma, cutaneous angiolipoleiomyoma, and cutaneous angiomyxoma are here covered because of their significant vascular component. Finally, we review briefly a series of cutaneous disorders that have been erroneously considered as vascular neoplasms. Kimura's disease is an inflammatory reactive condition of unknown origin, "benign" angioendotheliomatosis is a reactive intravascular proliferation of endothelial cells that occurs in the skin as a response to a variety of stimuli, "malignant" angioendotheliomatosis is an intravascular lymphoma, and acral pseudolymphomatous angiokeratoma of children (APACHE) is better interpreted as a pseudolymphoma.