[Anal and vulvar hidradenoma papilliferum are similar: A study of 14 cases]

Hidradenoma papilliferum (HP) is an adenomatous proliferation of mammary-like glands. These glands are located preferentially on the vaginal labia, the perineum and the anal skin. About ninety percent of HP occur on the vulva, with anal localization being much less common.

To analyze the clinical and histological characteristics of anal HP and compare them to those seen on the vulva based on the literature.

A monocentric retrospective analysis (in the medical and surgical proctology department of the Saint-Joseph Hospital Group, Paris) of patients for whom a diagnosis of anal HP was made based on pathological analysis of a resected sample.

A total of 14 female patients were included between 2012 and 2018. The mean age was 48.2 years (22-70). The tumor, single in all cases, was asymptomatic with very slow progression. It was located on the anal skin in all patients. It generally consisted of a round nodule measuring under 1cm that was barely prominent, translucent, depressible and mobile. In 15% of patients the tumor was ulcerated. Histologically, the tumor displayed the usual characteristics of HP. Only one relapse was seen, six years after resection.

The clinical and histological aspects of anal HP are the same as those of the vulva, which are better documented, namely a small, rounded, pink, translucent or bluish, and mobile tumor, with a smooth surface, and more rarely ulceration or budding, and in most cases asymptomatic. All HP were diagnosed in women and were located at the anal margin. Histopathological examination of an excised sample confirms the diagnosis and rules out a malignant tumor. The frequency of anal HP may be underestimated.