Background

Cutaneous, superficial and or suprafascial leiomyoma are divided into three variants: piloleiomyomas (PL), angioleiomyomas (AL) and genital leiomyomas (GL) that include the vulvar, scrotal and areolar forms. This study set out to establish the clinical and histological characteristics and incidence of each variant, and any likely associations with internal neoplasms.

Methods

A review was carried out of 255 cases of cutaneous leiomyomas diagnosed between 1982 and 2018 at the Pathology departments of three hospitals (Navarra and Alicante). Demographic, clinical, histological and immunohistochemical variables were described and compared.

Results

The incidence of PL in Navarra was 4.3 cases per million inhabitants a year, with another 20 cases of AL and 1.4 cases of GL. Cutaneous forms make up approximately 3.5% of the total leiomyomas. The population with PL suffered more frequently from breast cancer (OR = 4.8; CI 95%: 1.3-17.4; p = 0.006). Nipple leiomyomas are small, accompanied by localised pain, and are predominantly fascicular or solid, with very infrequent effect on the subcutaneous cellular tissue and scarce atypia. This makes for a contrast with the other GLs, which are medium sized and infrequently painful, predominantly nodular, and frequent effect on the subcutaneous tissue and atypia.

Conclusions

The information provided here about the clinical and histological characteristics of the different varieties of leiomyomas indicate that there is a need to reconsider the classification of nipple leiomyomas outside the group of GLs. An association between PL and breast carcinoma was detected, which needs to be confirmed in future studies so as to determine if this leiomyoma is a risk marker for breast cancer.