Apocrine carcinoma is a malignant tumor of the sweat glands characterized by a variety of macroscopic images. The course of this type of cancer is more severe than that of squamous cell carcinoma. Cancer usually appears in adults, and single lumps are most often located in the armpits and groin. The tumor may spread to nearby lymph nodes.
Tumors of the sweat glands
They are rare cancers with a variety of macroscopic images. They usually appear in adult patients over 50 years of age. The tumors accompanying the cancer are usually located in the groin and armpits, but also in the trunk and limbs. In addition, they can infiltrate adjacent tissues and metastasize to nearby lymph nodes. Tumors of the sweat glands have a patchy weaving, and their diagnosis is based, inter alia, on a histochemical examination. The treatment of this disease is complex (not fully researched due to the limited amount of information on this subject), however, surgical removal with a margin of healthy tissue and removal of adjacent lymph nodes are often performed.
Types of human sweat glands
Among human sweat glands we distinguish:
1. Apocrine glands – they usually occur in the armpits, groin, nipple, eyelids or anus. Their development comes from the hair follicle under the sebaceous gland after the formation of the eccrine glands. The apocrine glands include the excretory (end) part and, of course, the discharge channel leading to the epidermis or hair canal. Moreover, these glands affect emotional stimuli and their activity takes place in the period of sexual maturation.
2. Eccrine glands – their development is not related to the hair follicles and occurs around the 4th month of gestation. Initially, they are located on the inside of the hands, on the sole of the feet and on the forehead. They develop all over the skin over time. Unlike the apocrine glands, they do not attack the genital area (e.g. the surface of the foreskin). The eccrine glands consist of an excretory (glomerular) part and a tortuous discharge tube that flows out in the epidermis. The role of these glands is limited to regulating body temperature.
Recently, the authors have been trying to divide into tumors of eccrine and apocrine origin. However, it is relatively difficult as they show differentiation towards the sweat glands.
Cancer of apocrine origin
Apocrine cancer can occur as a single or multiple lesion. The nodules are hard and painless on physical examination, they may be cystic in nature, and their color is red or purple. In the course of microscopic examination, it can be seen that the tumor has well-developed lumen of the glands and apocrine secretion. These glands have basophilic cytoplasm.
The most common cancers of the sweat glands
1. Malignant sweat adenoma – is a rare skin cancer characterized by high malignancy. It usually appears in middle-aged women. Sweat adenoma is usually located on the chin, on the cheek or in the nasolabial area (less often in the armpits). Histopathological examination shows numerous horny cysts embedded in the stroma of the fibrous connective tissue. Treatment is based on the surgical excision of the Mohs method, which allows the margin of the lesion to be removed and the healthy tissue to be spared as much as possible. Sometimes radiotherapy is additionally implemented, e.g. when the lymph nodes are involved.
2. Mucinous cancer – is a rare skin cancer. Usually it is located on the face or scalp (in many cases the eyelids are affected). In some patients, neoplastic changes also appear on the nose, chin or in the armpits. Men get sick more often. The mucus cancer tumor is flesh-colored / pink or red in color, usually crusted, and grows slowly. It is usually locally malignant and does not spread to nearby lymph nodes. In the diagnosis of mucinous cancer, metastases should be excluded, and then appropriate treatment should be implemented, i.e. surgical removal of the lesion (the Mohs method is recommended because the risk of recurrence is significantly delayed).
3. Primary cutaneous cystic adenocarcinoma – is a cancer that usually affects the scalp, chest and face. It usually occurs in adults over the age of 60 (more often in women). This neoplasm is prone to recurrence, and metastasis is relatively rare. The origin of this cancer is debatable – some researchers believe that it originates from eccrine glands, while others point to apocrine origin. Nevertheless, the tumor has a sieve pattern of growth due to the presence of microcystic spaces. In cystic adenocarcinoma, the infiltration of the reticular layer of the dermis and the perineural area is characteristic. For this reason, the neoplastic lesion should be removed as soon as possible, as a local recurrence may occur. Treatment is based on surgical removal of the tumor with a margin of healthy tissue, while in the case of metastatic malignant cancer, chemotherapy and radiotherapy are additionally implemented.
Tumors developing from the sweat glands appear very rarely, therefore the literature lacks a large amount of publications on this subject that would help specialists in making an appropriate diagnosis and treatment. First of all, it is important to conduct further examinations in patients in order to find out the exact histopathological structure of the tumor.