Background: Hereditary syndromes frequently need the cooperation of different specialties to increase diagnostic competence. Multiple cutaneous and uterine leiomyomatosis syndrome is a rare autosomal dominant disorder caused by the mutations of the fumarate hydratase gene, demonstrated in 80 to 100 percent of affected individuals. This can be linked to an increased risk of renal cancer in both sexes. The skin involvement is described to highlight the diagnostic role of the cutaneous counterpart in identifying this rare syndrome.
Case presentation: A 37-year-old woman suffering from several uterine fibroids presented multiple, painful, papulo-nodules on her left subscapular side, both forearms and legs. The patient underwent surgery on six lesions: five were leiomyomas, whilst one was a dermatofibroma. Genetic sequencing did not evidence known fumarate hydratase gene mutations. Dermoscopy showed a brown delicate pigmented network and included leiomyomas among the non-melanocytic benign skin tumours featuring a dermatofibroma-like pattern. Abdominal computerized-tomography scan did not reveal renal cancer, but brain magnetic resonance imaging showed one asymptomatic cerebral cavernoma. The patient benefited from the surgical removal of the five larger cutaneous lesions and from gabapentin, which relieved her pain.
Conclusions: This observation highlights the usefulness of dermoscopy in the diagnosis of cutaneous leiomyomas disclosing multiple cutaneous and uterine leiomyomatosis syndrome. Dermoscopy should be performed for non-melanocytic multiple lesions mimicking leiomyomas in a large number of patients, to establish a strict classification and identify false negative cases or evaluate them as dermatofibromas. In this case, the dermatologist recognized the risk of renal cancer and cerebral cavernomas.