Abstract: The co-occurrence of multiple cutaneous leiomyomas (MCL) and psoriasis vulgaris (PV) is exceptionally rare, with no established pathophysiological link between these two conditions. We present a case of a 56-year-old woman with a 10-year history of widespread psoriatic plaques who presented with the concurrent development of multiple, firm, dark red papules and nodules. Histopathological examination confirmed the diagnosis of MCL, revealing interlacing bundles of spindle-shaped smooth muscle cells in the dermis, which were immunoreactive for smooth muscle actin and desmin. A separate biopsy from a psoriatic plaque showed characteristic features of PV. The patient was treated with a combination of thalidomide and tofacitinib, resulting in significant symptomatic and clinical improvement. This unique case highlights a potential, yet unexplored, interplay between smooth muscle proliferation and chronic inflammation, suggesting that shared immunogenetic mechanisms warrant further investigation. Clinicians should be aware of such unusual comorbidities when managing complex dermatological cases. Keywords: cutaneous leiomyoma, multiple cutaneous leiomyomatosis, psoriasis vulgaris, coexistence, immunomodulatory therapy, pathogenesis
Yu et al. (2026) studied this question.