Vulvar apocrine adenoma

　　1. Etiology

　　It is generally believed that eccrine adenomas occur in apocrine glands, but it is unknown whether they originate from apocrine secretory glands or primordial gland structures. The reasons supporting the occurrence in apocrine glands are: apocrine cells do not have secretory function before puberty, and they only start to secrete during puberty. Adenomas indeed do not occur before puberty, but there are still some points that cannot be explained, such as the armpits, areola, and mons pubis, which have a rich number of apocrine cells. There are also a small number of apocrine cells in the eccrine glands, but adenomas occur very rarely, while the chance of occurrence in the perineum and perianal area is higher. Moreover, the apocrine sweat glands in blacks are three times larger than those in whites, and the incidence rate should also increase accordingly. However, literature reports that the incidence rate in blacks is actually lower.

　　关于小阴唇汗腺瘤的来源，亦有争论。假使汗腺瘤发生于顶浆细胞始基，那么应在其附近找到毛囊，但在小阴唇部往往难以找到。Woodworth研究这些腺体，发现其比一般皮肤的小汗腺大些，比顶浆腺体小些，用普鲁士蓝染色，可以鉴别是小汗腺细胞还是顶浆细胞，因顶浆细胞内含有铁成分，而小汗腺细胞则无，作者证实小阴唇内的汗腺上皮细胞并不含铁。故有人认为小阴唇内汗腺瘤的来源，既不是小汗腺，亦不是大汗腺，而是介于两者之间的另一种类型的腺体，是小阴唇所特有的。

　　2、发病机制

　　肿瘤一般为单个圆形的实性结节，质软，表面被覆正常皮肤。偶可破溃、外翻，形成红褐色乳头状瘤样肿块，而且易出血，颇似癌变或炎性肉芽。肿瘤位于真皮浅层，紧贴表皮，直径0.1～1cm，平均0.8cm，界限清楚。

　　镜下形态类似于乳腺大导管的乳头状瘤，瘤内可见很多管状或囊状空腔，腔内有互相吻合的乳头状突起，其表面有二层细胞，即腔壁和乳头常衬以单层大汗腺型高柱状细胞，胞核较大，淡染，胞质嗜酸，常有顶浆分泌；其外周有一层断续排列的立方肌形上皮细胞。

　　肿瘤一般为单个圆形的实性结节，质软，表面被覆正常皮肤。偶可破溃、外翻，形成红褐色乳头状瘤样肿块，而且易出血，颇似癌变或炎性肉芽。肿瘤位于真皮浅层，紧贴表皮，直径0.1～1cm，平均0.8cm，界限清楚。并发症为易发生表浅溃疡和并发感染。

　　The growth site is often in the area between the labia majora and minora, around the perianal and perineal regions. Due to the lack of sweat glands in the labia minora, it rarely occurs, and there are usually no clinical manifestations, only a feeling of a hard lump. In a few cases, symptoms such as pain, tingling, and burning may occur. If it breaks open and secondary infection occurs, local pain, discharge, bleeding, odor, and fever may occur. Large hidradenomas of the vulva are often found incidentally during gynecological examination, where a rounded lump slightly elevated above the skin is observed. The lesion is usually solitary, with clear boundaries. The course of hidradenoma varies in length, with some lasting for more than a decade without change. However, during pregnancy, it can rapidly increase in a short period. Generally, the diameter of hidradenomas is about 1cm, with those larger than 2cm being rare.

　　The clinical manifestations of hidradenoma are divided into three types:

　　1. Cystic type, resembling a sebaceous cyst;

　　2. Solid type, manifested as a subcutaneous hard nodule;

　　3. Ulcerative type, after the surface skin is necrotic, the sweat gland tissue protrudes red granuloma or papillary-like from the wound, at this time, the appearance is extremely similar to a cancerous tumor.

　　Hidradenomas are rare, 80% occurring in women over 50 years old.

　　Prognosis: generally benign, rarely malignant. The prognosis is good. Only Eichenberg has reported 1 case of malignant hidradenoma with inguinal lymph node metastasis. Other few cases reported in the literature as malignant, some were later proved not to be malignant, and some were found not to be of sweat gland origin after re-examination, so Watkins et al. believe that hidradenomas are all benign without malignancy. In the past, there was a lack of understanding of this disease, and it was suspected to be malignant, so some underwent extensive vulvectomy, and some were treated with radiotherapy after local resection. Now, the general treatment method is to perform a biopsy first, confirm the diagnosis, and then perform local resection.

　　In addition to clinical manifestations, related examinations are also indispensable for the diagnosis of vulvar hidradenoma. The methods of examination are as follows:

     1. Tumor marker examination, secretion examination.

　　2. Histopathological examination.

　　1. Fever, prone to respiratory and urinary tract infections.

　　2. Long-term chronic poisoning can cause calcification of bones, kidneys, blood vessels, and skin, affecting physical and intellectual development.

　　3. High blood calcium and high urine calcium are prone to form kidney stones. Severe cases can lead to death due to renal failure.

　　4. Vitamin D poisoning in early pregnancy can cause hypercalcemia in the fetus, leading to congenital malformations.

　　Vulvar hidradenoma is a tumor formed by the hyperplasia of sweat gland epithelium, which is generally benign and rarely malignant. Since the large sweat glands only have function after sexual development matures, this type of hidradenoma occurs after adulthood. The main growth site is the labia majora.

　　Surgical treatment for the Western medical treatment of vulvar hidradenoma:

　　Surgical resection is used to clarify the diagnosis and exclude other lesions.

　　It is recommended to perform a biopsy first, and then perform local resection after confirming the diagnosis of vulvar hidradenoma.