Absence of Kaposi's sarcoma–associated herpesvirus in lesions of mycosis fungoides in patients with concomitant Kaposi's sarcoma

Is Kaposi sarcoma a novel comorbidity of cutaneous lymphoma? A systematic review of the literature

BACKGROUND AND OBJECTIVES

Patients with cutaneous lymphomas (CL) are at an increased risk of developing secondary malignancies. This study aimed to assess the frequency of association between CL and Kaposi sarcoma (KS) and to identify factors that may promote the co-occurrence of these two diseases.

PATIENTS AND METHODS

On January 25, 2024, we conducted a systematic search of four electronic medical databases to identify all published cases of KS associated with CL. The clinical course and outcomes of these patients were summarized. For critical appraisal, we applied the JBI Checklist for Case Reports. The study was registered in the PROSPERO database (CRD42022313204).

RESULTS

A total of 40 articles reporting on 45 patients were assessed for eligibility. We included 27 cases in the final analysis (26 cutaneous T-cell lymphomas, 1 cutaneous B-cell lymphoma). In 71% of cases, the diagnosis of CL preceded KS. Nearly half (48%) of the patients had erythrodermic mycosis fungoides or Sézary syndrome. KS lesions were predominantly limited to the skin, with complete remission achieved in 53% of cases.

CONCLUSIONS

The association between KS and CL is rare, limiting our study due to the small sample size and potential reporting bias. Skin-targeted therapies, a restricted T-cell repertoire, and impaired T-cell responses in erythrodermic CTCL patients may contribute to the development of KS.

Mycosis fungoides and Kaposi's sarcoma association in an HIV-negative patient

The association of mycosis fungoides and kaposi’s sarcoma in HIV-negative patients is a rare phenomenon. The presence of human herpesvirus 8 (HHV-8) – associated with all forms of Kaposi’s sarcoma – has also been recently identified in mycosis fungoides lesions. However, a causal association between HHV-8 and the onset of mycosis fungoides has not been established yet. The present case reports a patient who developed Kaposi’s sarcoma lesions after a two-year UVB phototherapy to treat a mycosis fungoides. Negative immunohistochemistry staining for Kaposi’s sarcoma-associated herpesvirus in the initial mycosis fungoides lesions strengthens the absence of a link between Kaposi’s sarcoma-associated herpesvirus and mycosis fungoides. Immunosuppression caused by the lymphoma and prolonged phototherapy were probably the contribut ing factors for the onset of Kaposi’s sarcoma.

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.