Histological variants of cutaneous Kaposi sarcoma

An exophytic red-purple nodule on the hip

A 35-year-old man with Fitzpatrick skin type IV, born in Brazil, presented to the dermatology clinic with a 3-month history of an asymptomatic growth on the left hip. He reported no prior history of trauma.

A case of disseminated angiosarcoma-like Kaposi sarcoma presenting with unusual vesiculobullous lesions

Angiosarcoma-like Kaposi sarcoma represents a recently delineated rare histomorphologic variant of Kaposi sarcoma that can be difficult to distinguish from other vasoproliferative lesions. Conventional lesions of Kaposi sarcoma encompass patches, plaques, and nodules; however, rarely vesiculobullous lesions have been described. Angiosarcoma-like Kaposi sarcoma has never been previously reported to present with vesiculobullous lesions. Herein, we describe a unique case of disseminated angiosarcoma-like Kaposi sarcoma with vesiculobullous lesions as the initial manifestation of human immunodeficiency virus infection.

The complete Kaposi sarcoma-associated herpesvirus genome induces early-onset, metastatic angiosarcoma in transgenic mice

Kaposi sarcoma (KS) is the most common cancer in persons living with HIV. It is caused by KS-associated herpesvirus (KSHV). There exists no animal model for KS. Pronuclear injection of the 170,000-bp viral genome induces early-onset, aggressive angiosarcoma in transgenic mice. The tumors are histopathologically indistinguishable from human KS. As in human KS, all tumor cells express the viral latency-associated nuclear antigen (LANA). The tumors transcribe most viral genes, whereas endothelial cells in other organs only transcribe the viral latent genes. The tumor cells are of endothelial lineage and exhibit the same molecular pattern of pathway activation as KS, namely phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR, interleukin-10 (IL-10), and vascular endothelial growth factor (VEGF). The KSHV-induced tumors are more aggressive than Ha-ras-induced angiosarcomas. Overall survival is increased by prophylactic ganciclovir. Thus, whole-virus KSHV-transgenic mice represent an accurate model for KS and open the door for the genetic dissection of KS pathogenesis and evaluation of therapies, including vaccines.

Anaplastic Kaposi Sarcoma of the Right Colon, in a Young Man With Acquired Immunodeficiency Syndrome: A Rare Variant in an Unreported Organ

Kaposi sarcoma (KS) arises in the context of 4 epidemiologic-clinical settings: Classic, endemic, epidemic, and iatrogenic; the most serious types are endemic and epidemic, and visceral involvement occurs mostly in the latter. Several morphological variants of KS have been described, of which the anaplastic one is highly aggressive. We report the case of an anaplastic KS arising from the ascending colon in a 32-year-old human immunodeficiency virus (HIV)-positive male patient with a 6-year history of multiple mucocutaneous KS. Anaplastic KS is most frequent in endemic and classic settings; there are ten cases of anaplastic KS reported in HIV-positive male patients. There is now strong evidence that KS is a clonal neoplasm characterized by chromosomal instability at the molecular level. According to the morphological spectrum and contemporary hypotheses of oncogenesis, conventional KS should be considered an incipient endothelial neoplasia, multiple or single, and anaplastic KS, the fully developed stage of the malignant neoplasm.

Anaplastic Kaposi Sarcoma: A Clinicopathologic and Molecular Genetic Analysis

Kaposi sarcoma (KS) is a human herpesvirus 8 (HHV8)-associated vascular proliferation that most often involves the skin. Rarely, KS shows marked nuclear atypia or pleomorphism; such examples are known as "anaplastic" KS. This poorly characterized variant often pursues an aggressive course; little is known of its genetic landscape. This study evaluated the clinicopathologic and genomic features of anaplastic KS. We identified 9 anaplastic KS cases from 7 patients and 8 conventional KS cases, including a matched conventional KS and primary metastasis anaplastic KS pair from a single patient (anaplastic KS diagnosed 9 years after conventional KS). All patients with anaplastic KS were men, aged 51 to 82 years, who had locally aggressive tumors predominantly affecting the soft tissue and bone of the lower extremities (5/7 patients). Four patients were known to be HIV positive (all on antiretrovirals), 2 were HIV negative, and 1 was of unknown HIV status. The tumors showed angiosarcoma-like or pleomorphic spindle cell sarcoma morphology. Plasma cell-rich chronic inflammation and hemosiderin deposition were commonly present. Single-nucleotide polymorphism-based chromosomal microarray analysis showed the anaplastic KS cohort to demonstrate highly recurrent whole chromosome (chr) gains of chr 7, 11, 19, and 21, which primarily affected olfactory and G protein-coupled receptor signaling and losses of chr6_q and chrY. Compared with conventional KS, anaplastic KS cases showed significantly more total copy number alterations and more frequent gains of chr7 and chr11_q13.1 (MARK2, RELA, and ESRRA, including high copy number gain in 1 case). Pathway analysis demonstrated that these gains preferentially affected genes that facilitate cyclin-dependent cell signaling. Furthermore, anaplastic KS cases were phylogenetically distinct from conventional KS cases, including the patient-matched primary metastasis anaplastic KS pair and conventional KS. Our study is the first to demonstrate that a more complex genome and distinct copy number alterations distinguish anaplastic KS from conventional KS. Gains of chr7 and chr11_q13.1 appear central to biological transformation.

Human Herpesvirus 8 (HHV-8) Staining: A Savior in Early Kaposi Sarcoma

Kaposi sarcoma (KS) is a low-grade vascular neoplasm associated with human herpesvirus 8 (HHV-8) infection. The disease has various phases, and the morphology of the lesion may vary, especially in the early course of the disease, where the morphological features may not be even suggestive of Kaposi sarcoma. The authors take this opportunity to report a case of Kaposi sarcoma where the diagnosis was established because of HHV-8 staining rather than its histopathological features.

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.

Clinical update on cutaneous and subcutaneous sarcomas

BACKGROUND

Cutaneous sarcomas are uncommon cancers that can have a wide range of clinical symptoms and lead to considerable cutaneous as well as systemic morbidity.

AIM

The objective of this review article is to discuss epidemiology, clinical features, diagnosis, and therapy of different types of cutaneous sarcomas.

MATERIAL AND METHODS

Literature was screened to retrieve articles from PubMed/Medline and Google Scholar and related websites. Cross-references from the relevant articles were also considered for review. Review articles, clinical studies, systematic reviews, meta-analyses, and relevant information from selected websites were included.

RESULTS AND DISCUSSION

Cutaneous sarcomas have a negative effect on the quality of life. In their diagnosis, clinical presentation and histological evaluation are crucial. Complete surgical removal is the solution for more or less all cutaneous and subcutaneous sarcomas. The prognosis for cutaneous sarcomas is generally favorable since they tend to recur locally with distant metastases only on rare occasions. Patients having advanced disease should be treated in the setting of clinical trials if possible; choices include radiation therapy and systemic medicines. The value of innovative immunotherapy cannot be determined decisively at this time due to a paucity of relevant trials.

CONCLUSION

As cutaneous sarcomas are rarely diagnosed based on clinical findings, histology plays an important role in the diagnosis. They have a relatively favorable prognosis if treated properly. Patients should be treated at specialized centres.

A Case of a Rare Histologic Variant: Cavernous Hemangioma-Like Kaposi Sarcoma

ABSTRACT

Kaposi sarcoma (KS) is an endothelial tumor associated with human herpesvirus 8. Cutaneous lesions can present with pink or purple patches, plaques, and nodules which can be ulcerated. The main subtypes of KS generally have similar histologic appearances, with spindle cells and expression of human herpesvirus 8 being characteristic features. However, various histologic variants have been reported. We present the case of a 55-year-old man with cutaneous KS with cavernous hemangioma-like histological features. Cavernous hemangioma-like KS is a rare morphologic type of KS, with only a handful of cases reported in the literature.

Clinical, Dermoscopic, Ultrasonographic, and Histopathologic Correlations in Kaposi's Sarcoma Lesions and Their Differential Diagnoses: A Single-Center Prospective Study

(1) Background: Kaposi's sarcoma (KS) is an angioproliferative neoplasm typically appearing as angiomatous patches, plaques, and/or nodules on the skin. Dermoscopy and ultrasonography have been suggested as an aid in the diagnosis of KS, but there is little evidence in the literature, especially regarding its possible differential diagnoses. Our aim is to describe and compare the clinical, dermoscopic, and ultrasonographic features of KS and KS-like lesions. (2) Methods: we conducted a prospective study on 25 consecutive patients who were first referred to our tertiary care center from January to May 2021 for a possible KS. (3) Results: 41 cutaneous lesions were examined by means of dermoscopy, Doppler ultrasonography, and pathology, 32 of which were KS-related, while the remaining 9 were lesions with clinical resemblance to KS. On dermoscopy, a purplish-red pigmentation, scaly surface, and the collarette sign were the most common features among KS lesions (81.3%, 46.9%, and 28.1%, respectively). On US, all 9 KS plaques and 21 KS nodules presented a hypoechoic image. Dermoscopic and Doppler ultrasonographic findings of KS-like lesions, such as cherry angioma, venous lake, glomus tumor, pyogenic granuloma, and angiosarcoma were also analyzed. (4) Conclusions: dermoscopy and Doppler ultrasonography can be useful to better assess the features of KS lesions and in diagnosing equivocal KS-like lesions.

Angiosarcoma-like Kaposi Sarcoma: A Distinctive Histomorphologic Variant Representing an Important Diagnostic Pitfall

Kaposi sarcoma (KS) is a rare low-grade angioproliferative neoplasm associated with human herpesvirus 8 (HHV-8) infection with multiple clinical subtypes and varying histopathologic patterns. Histologically, many different variants of KS have been reported, yet all can be difficult to recognize and must be differentiated from other vascular tumors. In this report, we studied fourteen cases of a newly described variant of KS reminiscent of a well-differentiated angiosarcoma (angiosarcoma-like KS). All cases showed a diffuse, ill-defined infiltrative dermal-based lesion composed of numerous anastomosing vascular channels of varying caliber lined by a single layer of endothelium with minimal pleomorphism. The vascular proliferation ramified through the dermis and dissected the collagen bundles along with infiltration into the subcutaneous fat and around skin appendages. All cases showed expression of vascular markers (CD31, CD34, and ERG) and were positive for HHV-8. None showed the classic histopathology associated with KS. Without clinical guidance these tumors can be difficult to recognize as KS, creating significant diagnostic challenges. Our study expands on a rare histologic variant of KS that ought to be considered in the differential diagnosis of any cutaneous well-differentiated angiosarcoma. Awareness of this variant of KS is of important for proper diagnosis and management of these patients; thus, careful attention to the histomorphology and clinical history can help lead the pathologist to the correct diagnosis.

Ocular Kaposi Sarcoma Associated With Systemic Disease and Complete Resolution After Medical Therapy

This case report describes a man with untreated HIV infection who presented with Kaposi sarcoma caruncular lesions that resolved completely with medical treatment.

Pneumonia or Kaposi Sarcoma: Beneath the Dyspnea With Non-compliance of HIV

Human herpesvirus 8 (HHV-8) or Kaposi sarcoma herpesvirus is the cause of Kaposi sarcoma (KS), the most prevalent cancer related to acquired immune deficiency syndrome. About 90% of the time, KS is accompanied by cutaneous lesions; however, systemic illness can develop without cutaneous involvement. Today’s highly active antiretroviral therapy (HAART) era has seen a decrease in the prevalence of KS. In immunocompromised individuals, it may be challenging to differentiate between pneumonia and the clinical characteristics of pulmonary KS, which might make diagnosis more challenging. HAART is the first-line therapy for KS, and its usage has reduced the incidence of KS. Depending on how severe the illness is, systemic chemotherapy could be helpful. We report the case of a young man who presented with pulmonary symptoms in the presence of a pharyngeal mass and was later found to have bilateral pulmonary metastasis. Interestingly, this diagnosis was made in the absence of classic cutaneous lesions. The patient was counseled for quality of life with medication and intervention compliance, and a consultation with an oncologist was set up.

Histologic Variants of Kaposi Sarcoma in the Gastrointestinal Tract: A Contemporary Multi-institutional Clinicopathologic Analysis of 46 Cases

Kaposi sarcoma (KS) can pose diagnostic challenges in biopsy specimens. Multiple histologic variants of cutaneous KS have been described; however, the histomorphologic spectrum of gastrointestinal (GI) KS has not been systematically studied. This large series comprehensively evaluated 46 cases of KS involving the GI tract and identified 7 histomorphologic variants, some that have not been previously described. Five of them are inconspicuous but have unique morphologic patterns, including lymphangioma/lymphangiectatic-like (n=17), mucosal hemorrhage/telangiectatic-like (n=17), mucosal inflammation-like (n=15), granulation tissue-like (n=13), and mucosal prolapse-like (n=4) variants. These variants can be easily misdiagnosed or misinterpreted on routine examination if KS is not considered, and if the immunohistochemical stain for human herpesvirus-8 is not performed. The other 2 morphologic variants present as spindle cell proliferations and are the GI stromal tumor-like (n=8) and inflammatory myofibroblastic tumor-like (n=2). These variants raise a broad differential diagnosis of spindle cell tumors of the GI tract and could pose diagnostic challenges. In summary, GI KS lesions exhibit variable, often unconventional histomorphologic patterns. KS should be included in the differential diagnosis even if features of conventional KS are not seen, particularly in limited biopsies in immunocompromised patients, such as those with human immunodeficiency virus infection. Although the clinical significance of these morphologic variants is yet to be determined, they are nonetheless important from a diagnostic standpoint. Misdiagnosis and delay in appropriate management can be avoided by recognizing the morphologic diversity of GI KS and appropriately utilizing the human herpesvirus-8 immunohistochemical stain.

Molecular Epidemiology of Human Herpes Virus Type 8 Among Patients with Compromised Immune System in Ouagadougou, Burkina Faso

Introduction

Human herpesvirus type 8 (HHV-8) is the main etiological agent of Kaposi's sarcoma. This virus is frequently associated with immunocompromision. This study aimed to detect HHV-8 in people with compromised immune system.

Patients and Methods

This is a cross-sectional study that included 180 subjects: 179 HIV-infected patients and 1 patient with bullous pemphigoid. Blood samples were taken from all subjects, and swabs of lesions were then taken from individuals with symptoms of Kaposi's sarcoma. Viral load and CD4+ T lymphocytes count were performed for persons living with HIV and real-time PCR detection of HHV-8 DNA was performed in all subjects in the study.

Results

Among HIV-infected persons, 13.41% had a viral load of more than 10,000 copies/mL, and 22.91% had a CD4+ T lymphocytes count of fewer than 350 cells/µL. A total of four (three HIV-1 infected patients and one patient with bullous pemphigoid) patients (2.22%) had apparent lesions of Kaposi's sarcoma. In the plasmas and swabs from associated lesions, HHV-8 DNA was found in only two individuals, with an HHV-8 prevalence of 1.11% (2/180) with 0.55% (1/179) in an HIV-infected patient on antiretroviral therapy.

Conclusion

These results exposing low prevalence levels of HHV-8 in HIV-infected patients could be due to the beneficial effect of antiretroviral drugs.

Kaposi's sarcoma: An interesting case report in a human immunodeficiency virus-positive heterosexual male

Kaposi's sarcoma (KS) is an angioproliferative neoplasm that affects skin and other organs. It is one of the acquired immune deficiency syndrome (AIDS)-defining conditions, which tends to occur at low CD4 count. It is the most common neoplasm among patients with AIDS in the Western population. It is rarely reported from India. We report the case of a 38-year-old human immunodeficiency virus-positive heterosexual male, with an unusual presentation of KS.

Kaposi’s sarcoma-associated herpesvirus vFLIP promotes MEndT to generate hybrid M/E state for tumorigenesis

Kaposi’s sarcoma (KS) is an angioproliferative and invasive tumor caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). The cellular origin of KS tumor cells remains contentious. Recently, evidence has accrued indicating that KS may arise from KSHV-infected mesenchymal stem cells (MSCs) through mesenchymal-to-endothelial transition (MEndT), but the transformation process has been largely unknown. In this study, we investigated the KSHV-mediated MEndT process and found that KSHV infection rendered MSCs incomplete endothelial lineage differentiation and formed hybrid mesenchymal/endothelial (M/E) state cells characterized by simultaneous expression of mesenchymal markers Nestin/PDGFRA/α-SAM and endothelial markers CD31/PDPN/VEGFR2. The hybrid M/E cells have acquired tumorigenic phenotypes in vitro and the potential to form KS-like lesions after being transplanted in mice under renal capsules. These results suggest a homology of KSHV-infected MSCs with Kaposi’s sarcoma where proliferating KS spindle-shaped cells and the cells that line KS-specific aberrant vessels were also found to exhibit the hybrid M/E state. Furthermore, the genetic analysis identified KSHV-encoded FLICE inhibitory protein (vFLIP) as a crucial regulator controlling KSHV-induced MEndT and generating hybrid M/E state cells for tumorigenesis. Overall, KSHV-mediated MEndT that transforms MSCs to tumorigenic hybrid M/E state cells driven by vFLIP is an essential event in Kaposi’s sarcomagenesis.

Kaposi’s sarcoma manifests as multifocal lesions with spindle cell proliferation, intense angiogenesis, and erythrocyte extravasation. Although the origin and malignant nature of KS remain contentious, it is established that KSHV infection with concomitant viral oncogene expression in normal cell progenitors causes KS. The mechanism of KSHV oncogenesis could be revealed through a reproduction of KS by infection of normal cells. This study reports that the KSHV infection of mesenchymal stem cells initiates mesenchymal-to-endothelial transition (MEndT) that generates mesenchymal/endothelial (M/E) hybrid state cells. The hybrid M/E cells acquired tumorigenic phenotypes, including tumor initiation, angiogenesis, migration, and the potential to form KS-like lesions after transplanted in mice. This finding faithfully recapitulates Kaposi’s sarcoma where proliferating KS spindle cells and the cells that line KS-specific aberrant vessels are also found to exhibit the hybrid M/E phenotype. We also found that KSHV-encoded viral FLICE inhibitory protein (vFLIP) plays a crucial role in promoting MEndT and the generation of M/E state cells. These results provide a new layer of evidence for KSHV-infected MSCs being the cell source of KS spindle cells and reveal novel insight into KS pathogenesis and viral tumorigenesis.

An Ecchymosis with Fulminant Evolution

We present the case of an 83-year-old woman who presented with an advanced cutaneous angiosarcoma of the head. The tumor had first appeared as a small ecchymosis on her forehead 3 months before admission. There was an extremely rapid and dramatic evolution, as evidenced by photographic documentation by her relatives. Unfortunately, the delay in access to the healthcare system due to the COVID-19 pandemic lockdown and the fulminant growth were the main determinants for our patient outcome.

Current and Future Tools for Diagnosis of Kaposi's Sarcoma

Simple Summary

Kaposi’s sarcoma, a rare opportunistic tumor, is observed in four epidemiological conditions (AIDS-related, iatrogenic, endemic or classic KS). Although in most cases KS is an indolent disease, it can be locally aggressive and/or it can invade other organs than the skin, resulting in more severe presentations, especially in patients with severe immunosuppression. There is no consensus on the imaging workup that is necessary for either the initial staging of the disease or the follow-up. Future perspectives include the use of certain non-invasive imaging tools that may help to evaluate the clinical response to treatment, as well as certain new histological markers that may help in guiding the treatment planning for this atypical neoplasm.

Abstract

Kaposi’s sarcoma (KS) is a rare, atypical malignancy associated with immunosuppression and can be qualified as an opportunistic tumor, which responds to immune modulation or restoration. Four different epidemiological forms have been individualized (AIDS-related, iatrogenic, endemic or classic KS). Although clinical examination is sufficient to diagnose cutaneous lesions of KS, additional explorations are necessary in order to detect lesions involving other organs. New histological markers have been developed in recent years concerning the detection of HHV-8 latent or lytic proteins in the lesions, helping to confirm the diagnosis when it is clinically doubtful. More recently, the evaluation of the local immune response has also been shown to provide some guidance in choosing the appropriate therapeutic option when necessary. We also review the indication and the results of conventional radiological imaging and of non-invasive imaging tools such as ¹⁸F-fluoro-deoxy-glucose positron emission tomography, thermography and laser Doppler imaging for the diagnosis of KS and for the follow-up of therapeutic response in patients requiring systemic treatment.

Clinicopathologic Correlation of Kaposi Sarcoma Involving the Ocular Adnexa: Immunophenotyping of Diagnostic and Therapeutic Targets

PURPOSE

To describe the clinicopathologic characteristics and the expression of diagnostic/treatment targets in ocular adnexal Kaposi Sarcoma.

METHODS

We conducted a clinical-pathologic retrospective case series. Immunohistochemical staining for cluster of differentiation 31 (CD31), human herpesvirus-8 (HHV8), platelet-derived growth factor receptor alpha (PDGFR-A), vascular endothelial growth factor receptor-1 (VEGF), tyrosine-protein kinase Kit (c-Kit), and programmed cell death protein 1 (PD-1) were performed. Percentage of positive tumor cells was recorded for PD-1; staining intensity and distribution (H-score) were determined for the remaining stains. A Friedman non-parametric ANOVA analysis evaluated the staining.

RESULTS

The study cohort included 13 patients (age 25 to 95 years; mean 46): 7 lesions were in the eyelid, 5 in the conjunctiva, and 1 in the cornea. Nine of 11 lesions (82%) were in human immunodeficiency syndrome-positive patients (human immunodeficiency syndrome status was unknown in 2 cases). Staging included 6 plaques and 7 nodules. The mean H-scores of CD31, HHV8, c-Kit, VEGF, and PDGF-A were 8.00, 8.23, 2.77, 11.54, and 10.31, respectively. Mean PD-1 staining was 6.46%. The Friedman non-parametric ANOVA analysis showed VEGF, PDGF-A, CD31, and HHV8 differed significantly, and all differed significantly from c-Kit. Programmed cell death protein 1 staining was not significant with any clinical variable.

CONCLUSIONS

Cluster of differentiation 31 and HHV8 are helpful diagnostic adjuncts for ocular adnexal Kaposi Sarcoma. Platelet-derived growth factor receptor alpha and VEGF are promising treatment targets. Programmed cell death protein 1/PD-L1 and c-Kit are targets that are useful in several tumors; their roles in ocular adnexal Kaposi Sarcoma warrant further studies.

Epithelioid Kaposi Sarcoma: A New Histological Variant

ABSTRACT

Cutaneous Kaposi sarcoma (KS) covers a broad spectrum both clinically and pathologically. Some histological patterns of KS may be difficult to recognize and must be differentiated from other vascular neoplasms. We report on a 56-year-old Peruvian man who had been diagnosed with classical KS on the right foot 2 years before the present episode. He presented in our clinic with new lesions on the left foot. Histopathological findings included areas showing epithelioid cells with moderate pleomorphism, growing in solid sheets. Immunohistochemistry showed strong nuclear staining with a granular nuclear staining pattern for human herpesvirus 8 in the epithelioid cells. A diagnosis of epithelioid Kaposi sarcoma was made, which should be considered a new histological variant.

CD4/CD8 Ratio and the Risk of Kaposi Sarcoma or Non-Hodgkin Lymphoma in the Context of Efficiently Treated Human Immunodeficiency Virus (HIV) Infection: A Collaborative Analysis of 20 European Cohort Studies

BACKGROUND

A persistently low CD4/CD8 ratio has been reported to inversely correlate with the risk of non-AIDS defining cancer in people living with human immunodeficiency virus (HIV; PLWH) efficiently treated by combination antiretroviral therapy (cART). We evaluated the impact of the CD4/CD8 ratio on the risk of Kaposi sarcoma (KS) or non-Hodgkin lymphoma (NHL), still among the most frequent cancers in treated PLWH.

METHODS

PLWH from the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) were included if they achieved virological control (viral load ≤ 500 copies/mL) within 9 months following cART and without previous KS/LNH diagnosis. Cox models were used to identify factors associated with KS or NHL risk, in all participants and those with CD4 ≥ 500/mm3 at virological control. We analyzed the CD4/CD8 ratio, CD4 count and CD8 count as time-dependent variables, using spline transformations.

RESULTS

We included 56 708 PLWH, enrolled between 2000 and 2014. At virological control, the median (interquartile range [IQR]) CD4 count, CD8 count, and CD4/CD8 ratio were 414 (296-552)/mm3, 936 (670-1304)/mm3, and 0.43 (0.28-0.65), respectively. Overall, 221 KS and 187 NHL were diagnosed 9 (2-37) and 18 (7-42) months after virological control. Low CD4/CD8 ratios were associated with KS risk (hazard ratio [HR] = 2.02 [95% confidence interval {CI } = 1.23-3.31]) when comparing CD4/CD8 = 0.3 to CD4/CD8 = 1) but not with NHL risk. High CD8 counts were associated with higher NHL risk (HR = 3.14 [95% CI = 1.58-6.22]) when comparing CD8 = 3000/mm3 to CD8 = 1000/mm3). Similar results with increased associations were found in PLWH with CD4 ≥ 500/mm3 at virological control (HR = 3.27 [95% CI = 1.60-6.56] for KS; HR = 5.28 [95% CI = 2.17-12.83] for NHL).

CONCLUSIONS

Low CD4/CD8 ratios and high CD8 counts despite effective cART were associated with increased KS/NHL risks respectively, especially when CD4 ≥ 500/mm3.

Intractable pleural effusion in Kaposi sarcoma following antiretroviral therapy in a Caucasian female infected with HIV

We report the case of a 57-year-old Caucasian woman with AIDS-related disseminated Kaposi sarcoma (KS) characterised by the combination of several unusual features. The chylous nature of the pleural effusions, the documented parietal pleural involvement at thoracoscopy and the marked clinical worsening through an immune reconstitution syndrome following antiretroviral therapy initiation represent several rare situations that occurred in the same female patient. In addition, the use of indwelling pleural catheters for dyspnoea palliation also represents a rare therapeutic intervention. This case is a reminder of the possibility of AIDS-related pleural KS, now uncommon in the era of antiretroviral therapy.

Interaction of Human Herpesvirus 8 Viral Interleukin-6 with Human Interleukin-6 Receptor Using In Silico Approach: The Potential Role in HHV-8 Pathogenesis

Introduction:

Human Herpesvirus 8 (HHV-8) causes classical, endemic (African), and Acquired Immunodeficiency Syndrome (AIDS)-related Kaposi’s Sarcoma (KS), Body Cavity-Based Primary Effusion Lymphomas (BCBL), HHV-8-associated peritoneal Primary Effusion Lymphoma (PEL), and Multicentric Castleman’s Disease (MCD). HHV8 genome encodes several structural and non-structural proteins, among which vIL6 is a functional homologue of Interleukin-6 (IL-6). It has been established that vIL6 plays a vital role in HHV8 infections; also, it has been suggested that its function was mediated through gp130, rather than the gp80 (IL-6 receptor [IL-6R]). This study aimed to investigate the physicochemical and structural properties as well as the immunological features, and finally the interaction between vIL6 and IL6 receptor (IL6R) by using several bioinformatics tools which could provide both valuable insight into vIL6 protein and advantageous data for further studies on HHV8 inhibitors and new vaccines.

Material and Methods:

vIL6, human IL6 (hIL6), and IL6R were obtained from NCBI GenBank and Uniport, which were aligned by The CLC Genomics Workbench. "Signal-BLAST" and “predisi" were employed to define signal peptide; also, “Expasy’sProtParam” was used to predict physicochemical properties as well as "DiANNA", and "SCRATCH" predicted the disulfide bonds. “NetPhosK”, “DISPHOS”, “NetPhos”, ”NetNGlyc”, and ”GlycoEP” were involved to determine post-modification sites. To define immunoinformatics analysis, “BcePred”, “ABCpred”, “Bepipred”, “AlgPred”, and "VaxiJen" were used. “SOPMA”, “I-TASSER”, “GalaxyRefine”, and “3D-Refine” predicted and refined the secondary and tertiary structures. TM-align server was used to align 3D structures. In addition, docking analysis was done by “Hex 5.0.”, and finally the results were illustrated by “Discovery Studio”.

Results:

A signal peptide (1-22) was defined in the vIL6 sequences and analysis has shown that vIL6 is an acidic protein which is significantly stable in all organisms. Three Disulfide bonds were predicted and immunoinformatics analysis showed 5 distinct B-cell epitopes. vIL6 is predicted as a non-allergen protein and the majority of its structure consists of Alpha helix. TM-align pointed the significant similarity between vIL6 and hIL6 in protein folding. The high energy value between vIL6 protein and IL6R was calculated and further analysis illustrated 5 conserved regions as well as 4 conserved amino acids which had a significant role in vIL6 and IL6R interaction.

Discussion:

An in silico study by numerous software determined the possible interaction between vIL6 and IL6R and the possible role of this interaction in HHV8 pathogenesis and the progress of infection. These have been overlooked by previous studies and will be beneficial to gain a more comprehensive understanding of vIL6 function during HHV8 lifecycle and infections. Structural analysis showed the significant similarity between vIL6 and hIL6 folding which can describe the similarity of the functions or interactions of both proteins. Furthermore, several conserved regions in the interaction site which interestingly were highly conserved among all vIL6 sequences can be used as new target for vIL6 inhibitors. Moreover, our results could predict immunological properties of vIL6 which suggested the ability of this protein in induction of the humoral immune response. Such a protein may be used for further studies on therapeutic vaccine fields.

Bacillary angiomatosis triggered by severe trauma in a healthy Caucasian patient: A case report

Bacillary angiomatosis represents a cutaneous and systemic infection caused by Bartonella species, typically described in the past in HIV-positive patients or associated with immunodeficiencies. More recent case reports had brought into attention the probability that this entity may manifest in otherwise healthy individuals, triggered by trauma and skin burns. The physiopathology of this neoproliferative process is based on the production of angiogenetic molecules, such as vascular endothelial growth factor (VEGF) and IL-8. In case of an inadequate treatment, the evolution can be fatal, with a systemic dissemination of the abscesses within the gastro-intestinal tract, respiratory tract, brain and bones. The appropriate therapy is with oral erythromycin and doxycycline, but several treatments such as cephalosporins, penicillins, macrolides, aminoglycosides, rifampin, dapsone, ciprofloxacin, have been tried with favorable results. Herein we present the case of a Caucasian patient, seronegative for HIV, who developed multiple vascular papules and nodules on the face, after a severe trauma and which healed after an adequate antibiotic therapy with oral clarithromycin.

Kaposi Sarcoma in Association With an Extracavitary Primary Effusion Lymphoma Showing Unusual Intravascular Involvement: Report of a Case Harboring a FAM175A Germline Mutation

Primary effusion lymphoma (PEL) is a rare form of aggressive B-cell lymphoma characterized by a malignant serous effusion involving body cavities. It usually associated with human herpes virus-8 (HHV-8) and coexpression of Epstein-Barr virus and mostly affects patients with HIV. We report a rare case of cutaneous PEL with an unusual intravascular presentation, combined with Kaposi sarcoma involving the skin, lung, and gastrointestinal tract. The molecular genetic analysis of the sarcoma and lymphoma components, using next-generation sequencing was performed. The patient was a 67-year-old man who presented with multiple cutaneous tumors and mass in the left lung. He died 17 hours after the admission to the hospital. At autopsy, in addition to the cutaneous lesions, tumors in the left lung and gastrointestinal mucosa were detected, and no effusions in the body cavities were seen. The biopsy from the cutaneous lesions, pulmonary, and intestinal tumors revealed histological and immunohistochemical features of Kaposi sarcoma. In addition, the skin biopsy specimens contained a diffuse infiltrate composed of large pleomorphic cells, with focal intravascular growth that were negative for pan B-cell markers, weakly positive for CD38 and CD138 but expressed CD3, HHV-8, and Epstein-Barr virus. Molecular genetic studies in this specimen revealed monoclonal rearrangements of the IgH gene. The diagnosis of PEL, solid variant, was made. Next-generation sequencing analysis of the tumorous and normal tissue detected a pathogenic germline mutation of the FAM175A gene and somatic mutations in BRCA2 and RAD51B (in both sarcoma and lymphoma specimens), and INPP4B and RICTOR (in lymphoma specimen only).

Kaposi Sarcoma Updates

Kaposi sarcoma (KS) is an angioproliferative mesenchymal neoplasm caused by Kaposi sarcoma-related herpesvirus. This review outlines our current understanding of the epidemiology, pathogenesis, clinical presentation, and staging for this disease. Recent research has informed a more comprehensive understanding of the epidemiology of KS in the post-antiretroviral therapy era, and highlights the continued need to better characterize the African endemic subtype. Advances in clinical oncology, including checkpoint inhibitors and new skin-directed therapies, have translated into exciting new developments for the future of KS treatment options.

A case of mistaken identity: classic Kaposi sarcoma misdiagnosed as a diabetic foot ulcer in an atypical patient

Background

The presentation of Kaposi sarcoma is divided into four known clinical subtypes. In this case report we describe classic Kaposi sarcoma in an African-American heterosexual, diabetic, seronegative human immunodeficiency virus male. Classic Kaposi sarcoma is rare in this patient demographic and can be easily misdiagnosed.

Case presentation

The patient presented with a lesion between the fourth and fifth digits of his right foot which was initially diagnosed as a diabetic foot ulcer. Despite local wound care, the lesion did not resolve. A shave biopsy was performed and histopathology findings were consistent with classic Kaposi sarcoma.

Conclusions

The patient tolerated local radiotherapy well and had complete resolution of his pedal lesion. There have been emerging associations between diabetes and Kaposi sarcoma. As such, clinicians should have a low threshold when considering the biopsy of suspicious pedal lesions in patients with diabetes. The utilization of appropriate biopsy technique may lead to the diagnosis of classic KS tumors in populations outside of the current four widely accepted clinical subtypes.

Anaplastic Kaposi's Sarcoma of the Adrenal in an HIV-negative Patient With Literature Review

Kaposi's sarcoma (KS) is a peculiar tumor of viral etiology, with the HHV8 rhadinovirus playing a fundamental role in its development. Several epidemiological categories of KS have been identified, of which the sporadic, endemic, iatrogenic, and the epidemic are the main ones. Several histologic disease morphologies have been described, such as inflammatory, angiomatous, spindle cell, mixed, and the anaplastic (sarcomatous) subtypes. The skin of the limbs is most commonly affected, but any other organ or site may be involved. Microscopically KS may enter the differential diagnosis with several different entities, and for this purpose the immunohistochemical detection of the viral latent nuclear antigen-1 (LNA-1) may be crucial. Sporadic KS is usually benign, but rarely it may be aggressive. Anaplastic histology heralds an ominous course in any clinical context. We report a case of anaplastic retroperitoneal KS, occurring in an HIV-negative adult man. This patient presented with a huge left suprarenal mass, which was totally resected, and initially diagnosed as inflammatory leiomyosarcoma, because of the monomorphic spindle cell tumor morphology. After 12 years the tumor recurred locally as an unresectable mass, which was biopsied and examined. At the time of recurrence, the histologic slides of the primary tumor were reviewed, and the previous diagnosis was changed to that of atypical KS. Histologically the recurrent tumor showed both spindle cell and epithelioid appearances. Strongly diffuse HHV8/LAN-1 immunopositivity was documented in both tumors. The final diagnosis for the entire case was anaplastic KS. Then, the patient died in a few months.

Kaposi sarcoma of th e penis in anHIV-negative patient

Kaposi sarcoma is an angioproliferative disorder that ranges from a single indolent skin lesion to respiratory and gastrointestinal/visceral involvement. Kaposi sarcoma is rare in non-immunosuppressed patients. Nineteen cases of penile Kaposi sarcoma in HIV-negative patients were reported in 2012. We present the case report of a 48-year-old male patient with no previous medical history, who came to our urology clinic presenting a purple-color papule on the penis glans. Lab tests revealed negative serology for HIV, but tissue PCR was positive for human herpesvirus 8. Histopathology examination after lesion excision was compatible with Kaposi sarcoma. No other cutaneous or mucosal lesions were present. Primary Kaposi sarcoma of the penis is rare, but may occur in non-immunosuppressed patients.

Kaposi sarcoma

Kaposi sarcoma (KS) gained public attention as an AIDS-defining malignancy; its appearance on the skin was a highly stigmatizing sign of HIV infection during the height of the AIDS epidemic. The widespread introduction of effective antiretrovirals to control HIV by restoring immunocompetence reduced the prevalence of AIDS-related KS, although KS does occur in individuals with well-controlled HIV infection. KS also presents in individuals without HIV infection in older men (classic KS), in sub-Saharan Africa (endemic KS) and in transplant recipients (iatrogenic KS). The aetiologic agent of KS is KS herpesvirus (KSHV; also known as human herpesvirus-8), and viral proteins can induce KS-associated cellular changes that enable the virus to evade the host immune system and allow the infected cell to survive and proliferate despite viral infection. Currently, most cases of KS occur in sub-Saharan Africa, where KSHV infection is prevalent owing to transmission by saliva in childhood compounded by the ongoing AIDS epidemic. Treatment for early AIDS-related KS in previously untreated patients should start with the control of HIV with antiretrovirals, which frequently results in KS regression. In advanced-stage KS, chemotherapy with pegylated liposomal doxorubicin or paclitaxel is the most common treatment, although it is seldom curative. In sub-Saharan Africa, KS continues to have a poor prognosis. Newer treatments for KS based on the mechanisms of its pathogenesis are being explored.

Quantitative RNAseq analysis of Ugandan KS tumors reveals KSHV gene expression dominated by transcription from the LTd downstream latency promoter

KSHV is endemic in Uganda and the HIV epidemic has dramatically increased the incidence of Kaposi sarcoma (KS). To investigate the role of KSHV in the development of KS, we obtained KS biopsies from ART-naïve, HIV-positive individuals in Uganda and analyzed the tumors using RNAseq to globally characterize the KSHV transcriptome. Phylogenetic analysis of ORF75 sequences from 23 tumors revealed 6 distinct genetic clusters with KSHV strains exhibiting M, N or P alleles. RNA reads mapping to specific unique coding sequence (UCDS) features were quantitated using a gene feature file previously developed to globally analyze and quantitate KSHV transcription in infected endothelial cells. A pattern of high level expression was detected in the KSHV latency region that was common to all KS tumors. The clear majority of transcription was derived from the downstream latency transcript promoter P3(LTd) flanking ORF72, with little evidence of transcription from the P1(LTc) latency promoter, which is constitutive in KSHV-infected lymphomas and tissue-culture cells. RNAseq data provided evidence of alternate P3(LTd) transcript editing, splicing and termination resulting in multiple gene products, with 90% of the P3(LTd) transcripts spliced to release the intronic source of the microRNAs K1-9 and 11. The spliced transcripts encode a regulatory uORF upstream of Kaposin A with alterations in intervening repeat sequences yielding novel or deleted Kaposin B/C-like sequences. Hierarchical clustering and PCA analysis of KSHV transcripts revealed three clusters of tumors with different latent and lytic gene expression profiles. Paradoxically, tumors with a latent phenotype had high levels of total KSHV transcription, while tumors with a lytic phenotype had low levels of total KSHV transcription. Morphologically distinct KS tumors from the same individual showed similar KSHV gene expression profiles suggesting that the tumor microenvironment and host response play important roles in the activation level of KSHV within the infected tumor cells.

Kaposi’s sarcoma (KS) is among the world’s most common AIDS-associated malignancies. The Kaposi sarcoma-associated herpesvirus (KSHV) was first identified in KS tumors and is now known to be the causative agent of all forms of KS, including classical, endemic, iatrogenic and HIV-associated. KSHV is endemic to sub-Saharan Africa with high infection rates in children and adults. Compounded with the high rate of HIV and AIDS in this area, pediatric and adult KS are some of the most common malignancies with the highest fatality rates. We used RNA deep sequencing to characterize KSHV expression in a large collection of KS biopsies from HIV-infected Ugandans. Using a novel approach to quantitate expression in complex genomes like KSHV, we found that RNA from a single KSHV promoter within the latency region constituted the majority of KSHV transcripts in the KS tumors. Alternate RNA processing produced different spliced and un-spliced transcripts with different coding potentials. Differential expression of other KSHV genes was detected which segregated the tumors into three different types depending on their expression of lytic or latency genes. Quantitative analysis of KSHV expression in KS tumors provides an important basis for future studies on the role of KSHV in the development of KS.

Non-cutaneous AIDS-associated Kaposi's sarcoma presenting as recurrent rectal abscesses

Kaposi's sarcoma is a fatal disease that typically presents with cutaneous manifestations in immunocompromised individuals. There are a small number of documented cases where patients diagnosed with this disease present without cutaneous lesions. We present a 35-year-old man with recurrent rectal abscesses and fistula-in-ano, which required multiple drainage procedures. Further investigation revealed a diagnosis of HIV-AIDS, and biopsy of a rectal mass confirmed the diagnosis of visceral Kaposi's sarcoma, despite the absence of cutaneous involvement. Workup revealed hepatic metastasis and a second pulmonary primary malignancy. The patient denied chemotherapy or further intervention and was subsequently lost to follow-up. Prompt diagnosis of Kaposi's sarcoma and initiation of treatment is vital to decrease disease progression. A high index of suspicion should be present in immunocompromised patients, and clinicians must recognise atypical presentations in order to improve long-term survival.

Primary Nasopharyngeal Kaposi Sarcoma as Index Diagnosis of AIDS in a Previously Healthy Man

A 38-year-old, previously healthy man presented with blood-stained saliva and epistaxis. A 3 mm nasopharyngeal lesion was found. A biopsy was performed and microscopic examination revealed a Kaposi sarcoma. The patient was subsequently found to be positive for human immunodeficiency virus (HIV). The diagnosis of Kaposi sarcoma in the presence of HIV infection advanced his disease to Acquired Immunodeficiency Syndrome (AIDS). Primary manifestation of Kaposi sarcoma in the nasopharynx is extremely rare. The histologic differential diagnosis of Kaposi sarcoma in this unusual site, especially without the clinical history of immunosuppression, is broad. Awareness that nasopharynx can be a primary involvement site of Kaposi sarcoma and serves as index diagnosis of AIDS is important given its serious clinical implication.

Recommendations for Counseling and Education of Service Members on Endemic African Cutaneous Kaposi Sarcoma: A Case Study

We report a case of Endemic African Cutaneous Kaposi Sarcoma (EACKS) on the lower extremity of an immunocompetent 31-yr-old male service member from Cameroon. Diagnosis was made using clinical and histologic findings. The service member was treated with local radiation therapy with resolution of his tumor.The goal of this article is to educate practitioners to counsel susceptible service members and leadership on the risk of developing EACKS when traveling to Sub-Saharan Africa, monitor for disease development, and guide in the diagnosis and treatment of patients with this rare disease.

Disseminated Kaposi sarcoma with epithelioid morphology in an HIV/AIDS patient: A previously unreported variant

Kaposi sarcoma is an oligoclonal HHV-8-driven vascular proliferation that was first described by a Viennese dermatologist Dr Moritz Kaposi. The disease has been seen in different clinical-epidemiological settings with a wide morphologic spectrum. We report a 52-year-old Caucasian man with HIV/AIDS and Kaposi sarcoma who presented with dyspnea and pleural effusion. He reported numerous tender subcutaneous nodules developing over the past few months on his chest, back and abdomen. An excisional biopsy of one of the nodules was performed. Touch preps revealed malignant cells in clusters. Microscopically, the neoplasm appeared undifferentiated with an epithelioid morphology, and involved the dermis and subcutaneous fat. Despite the medical history, Kaposi sarcoma was not considered foremost in the differential diagnosis. The malignant cells were positive for vimentin and negative for S100 protein, keratin AE1/3, CK7, CK20, napsin A, TTF-1 and synaptophysin. Additional stains revealed positivity for HHV-8, CD31 and D2-40, supporting the diagnosis of Kaposi sarcoma. Kaposi sarcoma has been well described with many variants that may cause diagnostic difficulty. An epithelioid variant has not been reported and consequently, may cause misinterpretation of an otherwise well-known entity that may become life threatening if appropriate treatment is not initiated in a timely manner.

Kaposi sarcoma herpesvirus pathogenesis

Kaposi sarcoma herpesvirus (KSHV), taxonomical name human gammaherpesvirus 8, is a phylogenetically old human virus that co-evolved with human populations, but is now only common (seroprevalence greater than 10%) in sub-Saharan Africa, around the Mediterranean Sea, parts of South America and in a few ethnic communities. KSHV causes three human malignancies, Kaposi sarcoma, primary effusion lymphoma, and many cases of the plasmablastic form of multicentric Castleman's disease (MCD) as well as occasional cases of plasmablastic lymphoma arising from MCD; it has also been linked to rare cases of bone marrow failure and hepatitis. As it has colonized humans physiologically for many thousand years, cofactors are needed to allow it to unfold its pathogenic potential. In most cases, these include immune defects of genetic, iatrogenic or infectious origin, and inflammation appears to play an important role in disease development. Our much improved understanding of its life cycle and its role in pathogenesis should now allow us to develop new therapeutic strategies directed against key viral proteins or intracellular pathways that are crucial for virus replication or persistence. Likewise, its limited (for a herpesvirus) distribution and transmission should offer an opportunity for the development and use of a vaccine to prevent transmission.

This article is part of the themed issue ‘Human oncogenic viruses’.

Head and Neck Kaposi Sarcoma: Clinicopathological Analysis of 11 Cases

Kaposi sarcoma (KS) of the head and neck area is uncommon with limited published case series. Our routine and consultation files were reviewed for histologically and immunohistochemically proven KS affecting any cutaneous or mucosal head and neck site. Ten males and one female aged 42-78 years (median, 51 years; mean, 52 years) were retrieved. Eight patients were HIV-positive and three were HIV-negative. The affected sites were skin (n = 5), oral/oropharyngeal mucosa (n = 5), and lymph nodes (n = 3) in variable combination. The ear (pinna and external auditory canal) was affected in two cases; both were HIV-negative. Multifocal non-head and neck KS was reported in 50% of patients. At last follow-up (12-94 months; median, 46 months), most of patients were either KS-free (n = 8) or had ongoing remission under systemic maintenance therapy (n = 2). One patient was alive with KS (poor compliance). Histopathological evaluation showed classical features of KS. One case was predominantly sarcomatoid with prominent inflammation mimicking undifferentiated sarcoma. Immunohistochemistry showed consistent expression of CD31, CD34, ERG, D2-40 and HHV8 in all cases. This is one of the few series devoted to head and neck KS showing high prevalence of HIV-positivity, but also unusual presentations in HIV-negative patients with primary origin in the skin of the ear and the auditory canal. KS should be included in the differential diagnosis of difficult-to-classify spindle cell lesions at this uncommon location.