Kaposi Sarcoma, a Trifecta of Pathogenic Mechanisms

Ocular Manifestations of Kaposi Sarcoma: Insights from an HIV-Positive Patient and an Immunocompetent HIV-Negative Patient

Kaposi sarcoma (KS) is a vascular neoplasm caused by human herpes virus-8 and is commonly associated with immunocompromised states such as acquired immunodeficiency syndrome. While ocular involvement is rare and typically occurs in human immunodeficiency virus (HIV)-positive patients, it can exceptionally present in HIV-negative, immunocompetent individuals. This report presents two cases of conjunctival KS: One in an HIV-positive patient and another in an HIV-negative patient. The patients were diagnosed and followed up at Istanbul Medeniyet University Göztepe Prof. Dr. Süleyman Yalçın City Hospital. Written informed consent was obtained from the patients for the preparation of this case report. A 35-year-old HIV-positive male with a history of cutaneous and genital KS presented with a painless, reddish, hemorrhagic mass on the left inferior fornix and a firm mass on the lower eyelid. Surgical excision with adjuvant cryotherapy and amniotic membrane transplantation was performed. One year postoperatively, no recurrence or new lesions were observed. A 76-year-old immunocompetent female presented with a painless, progressively enlarging mass in the left inferior fornix. She underwent surgical excision, adjuvant cryotherapy, and amniotic membrane transplantation. Histopathology confirmed the diagnosis of KS, and at the 1-year follow-up, no recurrence or new lesions were observed. Ocular KS, though rare, can occur in both immunocompromised and immunocompetent individuals. This report highlights the importance of considering KS in the differential diagnosis of subconjunctival hemorrhage, even in patients without underlying immunosuppressive conditions. Both cases were successfully managed with surgical excision, adjuvant cryotherapy, and amniotic membrane transplantation, with no recurrence during follow-up.

Protocol for the simultaneous isolation of DNA, RNA, and miRNA from a single archived Kaposi sarcoma biopsy

Kaposi sarcoma (KS) punch biopsies present unique challenges for extracting nucleic acids, which can be exacerbated by their long-term stabilization in RNAlater. Here, we present a protocol for simultaneously isolating DNA, RNA, and miRNA from a single KS punch biopsy. We detail the steps for preparing reagents and supplies, disrupting KS tissue using manual and mechanical methods, isolating DNA and total RNA, evaluating nucleic acid quality, and storing nucleic acids long-term.

Kaposi Sarcoma Involving Kidney Allografts: A Report of Two Cases From Qatar and Literature Review

Immunosuppression in kidney transplantation elevates the risk of malignancies, particularly immune-driven and virus-related cancers like Kaposi sarcoma (KS). KS typically manifests as single or multiple skin lesions following kidney transplantation but can also affect other organs. Involvement of the kidney allograft by KS is exceptionally rare, with only a few cases documented. In this report, we present all known cases of KS involving kidney allografts in adult transplant recipients in Qatar, accompanied by a brief review of the literature.

Kaposi's Sarcoma with Primary Lymph Node Involvement in a Retroviral Infected (RVI) Patient

One kind of angioproliferative disorder is Kaposi's sarcoma (KS). Growth of spindle-shaped cells, edema, inflammation, and neoangiogenesis are its defining features. Because it lacks the typical indicators of malignancy, it is classified as an intermediate neoplasm. People who are immunocompromised, receiving organ transplants, or receiving antiretroviral therapy are linked to KS. Although lymph node involvement by KS is extremely uncommon, when it does occur, it usually manifests as either the epidemic form in (Human Immuno-deficiency) HIV-positive patients or the endemic form in Africans. There are four primary clinical manifestations of KS that have been documented: endemic, epidemic, iatrogenic, and classic. The diagnosis of KS is made by history, physical examination, and tissue biopsy. When treating localized disease, highly active antiretroviral therapy (HAART) may be sufficient to either improve or completely eradicate the illness. Nonetheless, chemotherapy and HAART would be necessary in the case of widespread illness. Here, we present the case of a 28-year-old female patient who is HIV positive and has a viral load that is not detected. She presented with generalized lymphadenopathy of 8 months duration. She had no cutaneous manifestations. The lymphadenopathy involved the tonsils, axilla, inguinal, and an unusual site, intraparotid on both sides. After a pathologic examination of the lymph nodes, she was found to have epidemic-type KS and was treated with HAART and chemotherapy. In our nation, we are not aware of any published case reports pertaining to a case like this. The purpose of this case report is to raise physicians' awareness of this uncommon ailment and to encourage them to suspect KS when HIV patients exhibit generalized lymphadenopathy. The early initiation of systemic treatment is lifesaving for these patients.

Tertiary lymphoid structures in cancer: immune mechanisms and clinical implications

Cancer is a major cause of death globally, and traditional treatments often have limited efficacy and adverse effects. Immunotherapy has shown promise in various malignancies but is less effective in tumors with low immunogenicity or immunosuppressive microenvironment, especially sarcomas. Tertiary lymphoid structures (TLSs) have been associated with a favorable response to immunotherapy and improved survival in cancer patients. However, the immunological mechanisms and clinical significance of TLS in malignant tumors are not fully understood. In this review, we elucidate the composition, neogenesis, and immune characteristics of TLS in tumors, as well as the inflammatory response in cancer development. An in-depth discussion of the unique immune characteristics of TLSs in lung cancer, breast cancer, melanoma, and soft tissue sarcomas will be presented. Additionally, the therapeutic implications of TLS, including its role as a marker of therapeutic response and prognosis, and strategies to promote TLS formation and maturation will be explored. Overall, we aim to provide a comprehensive understanding of the role of TLS in the tumor immune microenvironment and suggest potential interventions for cancer treatment.

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.