Angioproliferative Lesions Research Articles

Delimiting CD34+ Stromal Cells/Telocytes Are Resident Mesenchymal Cells That Participate in Neovessel Formation in Skin Kaposi Sarcoma.

Kaposi sarcoma (KS) is an angioproliferative lesion in which two main KS cell sources are currently sustained: endothelial cells (ECs) and mesenchymal/stromal cells. Our objective is to establish the tissue location, characteristics and transdifferentiation steps to the KS cells of the latter. For this purpose, we studied specimens of 49 cases of cutaneous KS using immunochemistry and confocal and electron microscopy. The results showed that delimiting CD34+ stromal cells/Telocytes (CD34+SCs/TCs) in the external layer of the pre-existing blood vessels and around skin appendages form small convergent lumens, express markers for ECs of blood and lymphatic vessels, share ultrastructural characteristics with ECs and participate in the origin of two main types of neovessels, the evolution of which gives rise to lymphangiomatous or spindle-cell patterns-the substrate of the main KS histopathological variants. Intraluminal folds and pillars (papillae) are formed in the neovessels, which suggests they increase by vessel splitting (intussusceptive angiogenesis and intussusceptive lymphangiogenesis). In conclusion, delimiting CD34+SCs/TCs are mesenchymal/stromal cells that can transdifferentiate into KS ECs, participating in the formation of two types of neovessels. The subsequent growth of the latter involves intussusceptive mechanisms, originating several KS variants. These findings are of histogenic, clinical and therapeutic interest.

Unusual presentation of classical Kaposi Sarcoma: penile involvement in an HIV sero-negative patient

Background: Kaposi's sarcoma (KS) is a multifocal, angioproliferative malignant lesion originating from lymphatic endothelial cells. KS limited to the penis is extremely rare in human immunodeficiency virus (HIV) sero-negative patients. In this study, we aimed to present a case of isolated primary penile KS unrelated to HIV. Case Presentation: A 65-year-old man, with no risk factors for KS, presented with reddish nodules on penis. Biopsy was recommended to the patient for definitive diagnosis. Histopathological examination revealed that the diagnosis was classical type KS. No distant metastases were detected. No recurrence or disease progression was detected during the 4-year follow-up. Conclusion: Isolated primary penile KS is extremely rare in HIV sero-negative patients, but it should be kept in mind in the differential diagnosis of pigmented and nodular lesions in the penis. Excision of lesions with negative surgical margins has a high success and very low complication rate, as in our case.

Angiolymphoid hyperplasia with eosinophilia: A potential mimic of kimura’s disease

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a rare reactive angio-proliferative lesion. ALHE was initially classified as the late stage of Kimura’s disease (KD), although studies later showed that they were two separate clinical entities. Diagnosing ALHE remains a clinical challenge. Here, we report a case of ALHE in a young man and review current literature with an emphasis on how to distinguish ALHE particularly from KD. A 26-year-old man presented with a subcutaneous nodule in right infra-auricular area. Recurrence had occurred after three surgical excisions. Neither enlargement of salivary glands nor lymph nodes were found. Hematological examinations and renal function were normal. The mass was removed surgically. Microscopic examination showed proliferation of vascular channels with accompanying mixed inflammatory infiltrate consisting of lymphocytes, plasma cells, and eosinophils. Based on clinical data and histopathological examination, the patient was diagnosed with ALHE. Several clinical features differ between ALHE and KD, such as gender predilection, hypereosinophilia, IgE levels, and renal involvement. However, clinical features can overlap, so definitive diagnosis relies on histopathological examination. The most important hallmark of ALHE is vascular proliferation with epithelioid endothelial cells. Distinguishing ALHE from KD is important due to the lack of systemic manifestations in ALHE. However, ALHE can be easily mistaken for other diseases due to its rarity. Careful microscopic examination is very important to distinguish ALHE from KD and other mimicking lesions.

Oral Kaposi sarcoma development is associated with HIV viral load, CD4+ count and CD4+/CD8+ ratio.

Background Kaposi’s sarcoma (KS) is an uncommon, multifocal and angioproliferative lesion, which demonstrates a poor prognosis. The aim of the present research was to explore the association of HIV viral load, CD4+ and CD8+ counts and the CD4+/CD8+ ratio on the risk of oral Kaposi’s sarcoma (KS) development.Material and Methods A total of 62 patients were retrieved from March 2008 to October 2020 from the files of two oral pathology centres. Clinical, laboratory and follow-up data were retrieved from their medical files. Poisson regression was used to explore the role of history of immunosuppression and its association with oral KS development. A P-value <0.05 was considered significant.Results Sixty-two patients were included in the present study (32 with oral KS and 30 with no presentation of lesions anywhere on the body). Patients with oral KS presented a mean age of 32.6 years, and male patients were more affected. The hard palate (15 cases; 46.8%) was the main anatomical site affected. The lesions were mostly presented as swellings (13 cases; 40.6%) and nodules (12 cases; 37.5%). Systemic manifestations were also observed, including candidiasis (4 cases; 12.5%), bacterial infection (3 cases; 9.3%), tuberculosis (3 cases; 9.3%), herpes simplex (3 cases; 9.3%) and pneumonia (3 cases; 9.3%). A significant correlation was observed between HIV viral load, CD4+ count and the CD4+/CD8+ ratio with oral KS development.Conclusions HIV viral load, CD4+ count and the CD4+/CD8+ ratio are associated with oral KS development. Key words:Cancer, oral, Kaposi’s sarcoma, diagnostic.

Atypical benign angioproliferative lesion in a cat: Diagnostic imaging pitfalls

The authors present a case report of an atypical liver vascular malformation in a cat. The lesion was diagnosed first by ultrasound, fine needle aspiration and computed tomographic examination, which revealed the presence of a thin-walled single echogenic oval structure in the caudate lobe of the liver without visible flow in Doppler examination and with content similar to blood. The echogenicity of the lesion was variable, which depended on its size and time after aspiration. Initially, atypical haemangioma was suspected. After surgical removal, histopathological examinations were performed. The final diagnosis was a benign angioproliferative lesion.

Kaposi's sarcoma concealed by stasis dermatitis in a patient with psoriasis.

Kaposi's sarcoma (KS) is a multifocal and angioproliferative neoplasm. KS may be accompanied by psoriasis; however, in most of these cases the main mechanism involves iatrogenic KS associated with the immunosuppressive drugs that are used in psoriasis treatment. In angioproliferative lesions as a result of venous insufficiency and stasis dermatitis, acroangiodermatitis (pseudo-KS) is initially considered. However, the concurrent occurrence of psoriasis, stasis dermatitis, and KS has not been previously reported. We report a case of classic-type KS in an 83-year-old man that was concealed by stasis dermatitis and accompanied by psoriasis.

English

Acroangiodermatitis (Synonym: pseudo-Kaposi sarcoma) is an unusual, benign, self‑limited angioproliferative lesion. It is often associated with chronic venous insufficiency, arteriovenous malformation of the legs, chronic renal failure treated with dialysis, paralyzed legs and amputation stumps. This condition presents clinically as purple-colored patches, plaques or nodules on the lower extremities. Despite being benign, this lesion assumes importance because of its close resemblance to the aggressive Kaposi sarcoma and requires histopathological examination for its diagnosis. We describe here a case of a 55-year old female who presented with raised, hyperpigmented lesions over both ankles and histopathological examination from one of the lesions confirmed the diagnosis of acroangiodermatitis.

Erythropoietin Attenuates Pulmonary Vascular Remodeling in Experimental Pulmonary Arterial Hypertension through Interplay between Endothelial Progenitor Cells and Heme Oxygenase.

Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease with a high mortality, characterized by typical angio-proliferative lesions. Erythropoietin (EPO) attenuates pulmonary vascular remodeling in PAH. We postulated that EPO acts through mobilization of endothelial progenitor cells (EPCs) and activation of the cytoprotective enzyme heme oxygenase-1 (HO-1). Rats with flow-associated PAH, resembling pediatric PAH, were treated with HO-1 inducer EPO in the presence or absence of the selective HO-activity inhibitor tin-mesoporphyrin (SnMP). HO activity, circulating EPCs and pulmonary vascular lesions were assessed after 3 weeks. In PAH rats, circulating EPCs were decreased and HO activity was increased compared to control. EPO treatment restored circulating EPCs and improved pulmonary vascular remodeling, as shown by a reduced wall thickness and occlusion rate of the intra-acinar vessels. Inhibition of HO activity with SnMP aggravated PAH. Moreover, SnMP treatment abrogated EPO-induced amelioration of pulmonary vascular remodeling, while surprisingly further increasing circulating EPCs as compared with EPO alone. In experimental PAH, EPO treatment restored the number of circulating EPCs to control level, improved pulmonary vascular remodeling, and showed important interplay with HO activity. Inhibition of increased HO activity in PAH rats exacerbated progression of pulmonary vascular remodeling, despite the presence of restored number of circulating EPCs. We suggest that both EPO-induced HO-1 and EPCs are promising targets to ameliorate the pulmonary vasculature in PAH.

Spontaneous Acroangiodermatitis.

Acroangiodermatitis is a rare self-limited angioproliferative lesion which can be associated with congenital vascular malformations or acquired venous insufficiency. Despite of its benign character, differential diagnosis of this lesion is very important because it closely resembles Kaposi sarcoma. Here we present a 26-year-old male patient with unilateral, purplish-red colored papules on his right ankle which diagnosed as acroangiodermatitis and discuss histopathological features, differential diagnosis and treatment of this unusual condition.

Angiolymphoid hyperplasia with eosinophilia in parotid gland: A diagnostic challenge

Angiolymphoid hyperplasia with eosinophilia (ALHE) rarely involves the parotid glands or other major glands. ALHE and Kimura's disease (KD) share many clinical and histopathological features. Ill-defined, deeply seated lesions involving the parotid glands are frequently observed in KD, and only three cases of intraparotid ALHE have been reported in the literature. Often these benign angioproliferative lesions of unknown etiology will be misdiagnosed as parotid tumors clinically. We report a case of ALHE in a 29-year-old Indian male who presented with unilateral parotid enlargement. The previous fine-needle aspiration cytology (FNAC) report indicated parotid sialadenitis but histopathological examination following superficial parotidectomy of the lesion allowed us to make a definitive diagnosis.

Multiple epithelioid hemangiomas with orbital involvement.

Epithelioid hemangioma, also known as angiolymphoid hyperplasia with eosinophilia, is a cutaneous angioproliferative lesion that follows a benign clinical course. It is most frequently localized in the skin of the head and neck region; although it may sometimes arise deeper in soft tissues, orbital involvement is rare. Here we describe a patient who developed multiple epithelioid hemangiomas, including an intraorbital lesion. The histopathological parallels with other reactive and neoplastic lesions as well as therapeutic options are discussed.

Pulmonary arterial hypertension and sepsis: Prothrombotic profile and inflammation can changes pulmonary mechanics?

Pulmonary arterial hypertension (PAH) is associated to cellular and structural alterations of lung vasculature. Endothelial dysfunction promotes vasoconstriction, smooth muscle hypertrophy, intimal proliferation, angioproliferative plexiform lesions, and in situ thrombosis increasing pulmonary vascular resistance and arterial stiffness. Indeed, an inflammatory component has been defined in PAH on the last years. Sepsis is a systemic complex syndrome, of infectious origin. The presence of inflammation is well established in this condition and it is also considered a risk factor for acute lung injury. Thrombotic events play important role in sepsis pathophysiology. The association between PAH and sepsis potentiate the metabolic oxygen consumption/offer imbalance, with very high mortality risk. Furthermore, it is possible that the association of these two conditions should intensify thrombotic events on pulmonary microcirculation, reducing area of pulmonary vascular bed available for blood flow. For the other side, an inflammation synergism observed on these two conditions should increase the respiratory system impedance.

A rare case of angiolymphoid hyperplasia with eosinophilia in the submental region

Angiolymphoid hyperplasia with eosinophilia is a rare reactive, angio-proliferative lesion which is usually found in the subcutaneous tissue of the head and neck. The lesion rarely arises from a native blood vessel. It is of unknown etiology but may be related to some benign, localized form of vasculitis. While preauricular location is the most frequent site of occurrence as reported in literature, a lesion in submental region seems to be a first reported site of occurrence. We report such an occurrence in an individual with history of trauma twice in his lifetime at the affected site. Spontaneous regression is common, but persistent or recurrent lesions may require treatment. Several treatments have been reported but surgery is considered to be the most efficient one.

Angiomatosis bacilar por Bartonella quintana como primera manifestación de infección por VIH: Report of one case

Bacillary angiomatosis is an unusual infectious disease, with angioproliferative lesions, typical of immunocompromised patients. It is caused by Bartonella quintana and Bartonella henselae, two infectious agents of the genus Bartonella, which trigger variable clinical manifestations, including cutaneous vascular and purpuric lesions, and regional lymphadenopathy, and even a systemic disease with visceral involvement. We report a 38-year-old HIV positive male presenting with a history of six months of cutaneous growing purple angiomatous lesions, located also in nasal fossae, rhi-nopharynx and larynx. The skin biopsy was compatible with bacillary angiomatosis. Polymerase chain reaction of a tissue sample showed homology with B. quintana strain Toulouse. The patient was treated with azithromycin and ciprofloxacin with a favorable evolution.

Fibroblast Growth Factor-2 and the HIV-1 Tat Protein Synergize in Promoting Bcl-2 Expression and Preventing Endothelial Cell Apoptosis: Implications for the Pathogenesis of AIDS-Associated Kaposi's Sarcoma

Kaposi's sarcoma (KS) is a vascular tumor frequently occurring in Human Immunodeficiency Virus- (HIV-) 1-infected individuals. Our previous work indicated that the angiogenic fibroblast growth factor (FGF)-2 and the Tat protein of HIV-1, both expressed in KS lesions of HIV-infected patients, synergize at inducing angioproliferative, KS-like lesions in mice. Here we show that the development of angioproliferative lesions promoted in mice by combined Tat and FGF-2 associates with an increase in the levels of expression of the antiapoptotic Bcl-2 protein. Upregulation of Bcl-2 expression by combined FGF-2 and Tat occurs also in vitro, and this protects human primary endothelial cells from programmed cell death. As Bcl-2 is expressed in human KS lesions in a fashion paralleling the progression of the disease, these findings suggest a molecular mechanism by which Tat and FGF-2 cooperate in KS maintenance and progression in HIV-infected individuals.

Kaposi's sarcoma and its associated herpesvirus

Kaposi's sarcoma (KS) is the most common cancer in HIV-infected untreated individuals. Kaposi's sarcoma-associated herpesvirus (KSHV; also known as human herpesvirus 8 (HHV8)) is the infectious cause of this neoplasm. In this Review we describe the epidemiology of KS and KSHV, and the insights into the remarkable mechanisms through which KSHV can induce KS that have been gained in the past 16 years. KSHV latent transcripts, such as latency-associated nuclear antigen (LANA), viral cyclin, viral FLIP and viral-encoded microRNAs, drive cell proliferation and prevent apoptosis, whereas KSHV lytic proteins, such as viral G protein-coupled receptor, K1 and virally encoded cytokines (viral interleukin-6 and viral chemokines) further contribute to the unique angioproliferative and inflammatory KS lesions through a mechanism called paracrine neoplasia.

Bacillary angiomatosis in an immunosuppressed dog

A dog being treated with immunosuppressive doses of prednisone and azathioprine for pancytopenia of unknown origin, developed, over a 2-week period, multiple erythematous nodular lesions in the skin including footpads. Skin samples revealed lesions identical to those of human bacillary angiomatosis (BA). The nodules were composed of multifocal proliferations of capillaries, each lined by protuberant endothelial cells. The capillary clusters were separated by an oedematous connective tissue, lightly infiltrated with degenerate inflammatory cells, including neutrophils and macrophages. Tissue sections stained with Warthin-Starry silver stain revealed large numbers of positively stained bacilli in the stromal tissue, most heavily concentrated around the proliferating capillaries. Lesions of vascular degeneration and inflammation were evident. Bartonella vinsonii subsp. berkhoffii genotype 1 was independently amplified and sequenced from the blood and the skin tissue. The pathognomonic nature of the histological lesions, demonstration of compatible silver-stained bacilli in the tissue, and identification of B. vinsonii subsp. berkhoffii in the blood and tissue indicates that this is most likely the aetiologic agent responsible for the lesions. Antibiotic therapy was successful in resolving the nodules. It would appear that B. vinsonii subsp berkhoffii, like Bartonella henselae and Bartonella quintana, has the rare ability to induce angioproliferative lesions, most likely in association with immunosuppression. The demonstration of lesions identical to those of human BA in this dog is further evidence that the full range of clinical manifestations of human Bartonella infection occurs also in canines.

Gene expression profile in flow-associated pulmonary arterial hypertension with neointimal lesions

Pulmonary arterial hypertension (PAH) is a pulmonary angioproliferative disease with high morbidity and mortality, characterized by a typical pattern of pulmonary vascular remodeling including neointimal lesions. In congenital heart disease, increased pulmonary blood flow has appeared to be a key mediator in the development of these characteristic lesions, but the molecular mechanisms underlying the pulmonary vascular lesions are largely unknown. We employed a rat model of flow-associated PAH, which induced specific pulmonary neointimal lesions. We identified gene expression profiles in rats specifically related to the addition of increased pulmonary blood flow to monocrotaline and the associated occurrence of neointimal lesions. Increased pulmonary blood flow induced the expression of the transcription factors activating transcription factor-3 (ATF3) and early growth response factor-1 (EGR-1), for which presence was confirmed in neointimal lesions. Monocrotaline alone induced increased numbers of activated mast cells and their products. We further identified molecular pathways that may be involved in treatment with the prostacyclin analog iloprost, a vasoactive compound with clinically beneficial effects in patients with PAH, which were similar to pathways described in samples from patient studies. These pathways, associated with the development of angioproliferative lesions as well as with the response to therapy in PAH, may provide new therapeutic targets.

Induction of CCL20 production by Kaposi sarcoma–associated herpesvirus: role of viral FLICE inhibitory protein K13-induced NF-κB activation

AbstractKaposi sarcoma–associated herpesvirus (KSHV), also known as human herpesvirus 8, is the etiologic agent of Kaposi sarcoma (KS), an angioproliferative lesion characterized by dramatic angiogenesis and inflammatory infiltration. In this study, we report that expression of chemokine CCL20, a potent chemoattractant of dendritic cells and lymphocytes, is strongly induced in cultured cells either by KSHV infection or on ectopic expression of viral FLICE inhibitory protein K13. This induction is caused by transcriptional activation of CCL20 gene, which is mediated by binding of the p65, p50, and c-Rel subunits of the transcription factor nuclear factor–κB (NF-κB) to an atypical NF-κB–binding site present in the CCL20 gene promoter. The CCL20 gene induction is defective in K13 mutants that lack NF-κB activity, and can be blocked by specific genetic and pharmacologic inhibitors of the NF-κB pathway. CCR6, the specific receptor for CCL20, is also induced in cultured cells either by KSHV infection or on K13 expression. Finally, expression of CCL20 and CCR6 is increased in clinical samples of KS. These results suggest that KSHV and K13-mediated induction of CCL20 and CCR6 may contribute to the recruitment of dendritic cells and lymphocytes into the KS lesions, and to tumor growth and metastases.

Kaposi's Sarcoma-Associated Herpesvirus Upregulates Angiogenin during Infection of Human Dermal Microvascular Endothelial Cells, Which Induces 45S rRNA Synthesis, Antiapoptosis, Cell Proliferation, Migration, and Angiogenesis

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is associated with the angioproliferative KS lesions characterized by spindle-shaped endothelial cells, inflammatory cells, cytokines, growth factors, and angiogenic factors. De novo KSHV infection of human microvascular dermal endothelial cells results in increased secretion of several growth factors, cytokines, chemokines, and angiogenic factors, and the multifunctional angiogenic protein angiogenin is one of them. KS tissue sections were positive for angiogenin, highlighting the importance of angiogenin in KS pathogenesis. Examination of KSHV-mediated angiogenin upregulation and secretion and potential outcomes revealed that during infection of primary endothelial cells, KSHV induced a time- and dose-dependent increase in angiogenin gene expression and protein secretion beginning as early as 8 h postinfection and lasting until the fifth day of our observation period. TIVE latently transformed cells (TIVE-LTC) latently infected with KSHV secreted high levels of angiogenin. Angiogenin was also detected in BCBL-1 cells (human B cells) carrying KSHV in a latent state. Significant induction of angiogenin was observed in cells expressing KSHV ORF73 (LANA-1; latent) and ORF74 (lytic) genes alone, and moderate induction was seen with the lytic KSHV ORF50 gene. Angiogenin bound to surface actin, internalized in a microtubule-independent manner, and translocated into the nucleus and nucleolus of infected cells. In addition, it increased 45S rRNA gene transcription, antiapoptosis, and proliferation of infected cells, thus demonstrating the multifunctional nature of KSHV-induced angiogenin. These activities were dependent on angiogenin nuclear translocation, which was inhibited by neomycin. Upregulation of angiogenin led to increased activation of urokinase plasminogen activator and generation of active plasmin, which facilitated the migration of endothelial cells toward chemoattractants, including angiogenin, and chemotaxis was prevented by the inhibition of angiogenin nuclear translocation. Treatment of KSHV-infected cell supernatants with antiangiogenin antibodies significantly inhibited endothelial tube formation, and inhibition of nuclear translocation of angiogenin also blocked the expression of KSHV-induced vascular endothelial growth factor C. Collectively, these results strongly suggest that by increasing infected endothelial cell 45S rRNA synthesis, proliferation, migration, and angiogenesis, KSHV-induced angiogenin could be playing a pivotal role in the pathogenesis of KSHV infection, including a contribution to the angioproliferative nature of KS lesions. Our studies suggested that LANA-1 and vGPCR play roles in KSHV-induced angiogenesis and that the angiogenic potential of vGPCR might also be due to its ability to induce angiogenin.