Hidradenocarcinoma is a rare tumor caused by the abnormal growth of cells in a sweat gland. It is a type of cancer that usually begins as a single spot (lesion) on the skin of the head or neck, but can be been found on other parts of the body. This type of tumor most often develops in people between the ages of 30-60 years old, but has been found in children. Hidradenocarcinoma is usually painless and tends to grow slowly, but may spread into nearby tissues, especially lymph nodes, or to more distant parts of the body (metastasis). The cause of the tumor is unknown. Diagnosis is usually made by careful examination and a series of special skin tests. The main treatment is surgical removal of the tumor often followed by radiation therapy and/or chemotherapy. Long term outlook is best when the cancer is found early.

Medical researchers have not found any genetic change which a person is born with that may increase their risk for developing hidradenocarcinoma nor are there any reports in the literature which suggest this rare cancer runs in families.

Newer targeted therapies like trastuzumab, epidermal growth factor receptor (EGFR) inhibitors, PI3K/Akt/mTOR pathway inhibitors (targets a pathway believed to be involved in controlling cell growth and division), hormonal agents like antiandrogens, and electrochemotherapy (the use of electrical pulses to help get the chemo drugs into the cancer cells) may also be offered. Most of these therapies have only been reported in isolated case reports and often with conflicting results. Therefore it is difficult to determine which therapy or combination of therapies are the best treatment option. Options are usually determined by the size and location of the cancer and the extent to which cancer cells may have spread to nearby tissues.. Many researchers are hoping if there is a better understanding of the molecular genetic changes which happen in the cells of hidradenocarcinoma, the use of targeted therapies will improve long term prognosis.

Factors which seem to predict a better outcome include finding the cancer at an early stage and the ability to completely surgically remove the tumor. Prognosis is also better for younger individuals and those in good health. Tumors which do not respond to treatment have a poorer outlook, while the outlook for recurrent tumors is difficult to predict.