Disseminated myofibroblastic papulosis in young individuals: a newly identified entity-clinicopathologic study from a case series of 8 patients

Abstract Background Superficial dermal fibroblastic/myofibroblastic proliferation comprises a spectrum of tumors, most of which present as solitary lesions. Generalized forms are exceptionally rare. Objective To describe and analyze a novel entity clinically manifested as disseminated firm papules and histologically characterized by fibroblastic/myofibroblastic proliferation. Methods We conducted a retrospective analysis of eight patients diagnosed between 2010 and 2024, collected from four medical centers. Histopathological review of hematoxylin and eosin-stained sections was performed, alongside available immunohistochemical studies. Whole-exome sequencing was carried out on genomic DNA from three patients to explore potential genetic causes. Results The cohort consisted of 5 females and 3 males, aged 14–26 years (median 18.25), presenting with multiple skin-colored to dark red papules predominantly on the extremities, buttocks, and chest. Histopathology revealed fascicular proliferations of bland spindle cells within the superficial dermis. Immunohistochemically, lesions were weakly positive for SMA and negative for CD68, CD34, desmin, and S100 protein, with loss of elastic fibers. No relevant germline driver mutations were detected in peripheral blood DNA. Spontaneous regression occurred in five patients during follow-up. Conclusions We propose the term “disseminated myofibroblastic papulosis (DMP)” for this newly recognized, likely under-diagnosed entity. Given its benign behavior and frequent self-resolution, a watchful waiting approach after diagnosis is recommended.