The mechanisms of fat alterations in PWH are complex and not fully elucidated. In general, lipodystrophy has been observed as a frequent condition among PWH receiving ART, especially thymidine analogue nucleoside reverse transcriptase inhibitors and protease inhibitors; however, newer studies have demonstrated continued abnormalities in fat and/or lipid storage with newer antiretroviral classes, such as INSTIs [5]. Integrase strand inhibitors have been associated with increased adipogenesis and hypertrophy in both visceral and subcutaneous tissue as well as weight gain and metabolic syndrome [5, 6].

In contrast, efavirenz has been shown to reduce adipogenesis and adiponectin expression [7, 8]. In vitro studies have shown efavirenz causing a dose-dependent repression of adipocyte differentiation that is associated with down-regulation of the master adipogenesis regulator genes SREBP-1, PPARγ and C/EBPα, and their target genes encoding lipoprotein lipase, leptin and adiponectin, which are key proteins in adipocyte function [7, 8].

A similar case was reported regarding a female who switched from TDF/FTC/EFV to TAF/FTC/BIC and 18 months later developed bilateral facial angiomyolipomas [9]. The diagnosis was made on computed tomography as the patient refused a biopsy. As there was no definitive pathologic diagnosis and angiolipoma and angiomyolipomas may be difficult to differentiate [10], . that case may have described a related phenomenon.

Though it may be thought that this process had been a variant of HIV lipodystrophy, the exact mechanism of the appearance of multiple angiolipomas in our patient is not known. It is speculated that TDF/FTC/EFV suppressed angiogenesis which led to the development of these angiolipomas when switched to an ART that increased adipogenesis, such as TAF/FTC/BIC. The switch in ART resulted in dysregulation of homeostasis in adipocytes and the occurrence of angiolipomas.

The standard of care for the treatment of angiolipomas is to reserve surgical excision for locally invasive, painful, or cosmetically disfiguring lesions [1, 2]. In clinical scenarios where lesions continue to increase in size or number, an ART switch to an efavirenz- or rilpivirine-containing regimen may be warranted. As with efavirenz, rilpivirine may have similar impairment on adipogenesis, though at higher concentrations [11]. Another possible intervention may include switching to a protease inhibitor-based regimen to reduce angiogenesis [12]. Due to the scarcity of case reports available in this subject, it imperative that clinicians be vigilant to assess for such toxicities when switching ART.