Eccrine spiradenoma is a benign neoplasia originating from the tissue of the eccrine sweat glands. It has many variants of histological structure. It usually happens alone, multiple neoplasms are less common. It is a small dense rounded knot. The skin above the node has a normal color, cyanotic, reddish or grayish tint. Palpation is painful. Eccrine spiradenoma can be located on almost any part of the body, more often localized on the anterior surface of the trunk, head and limbs. Malignancy is rare. It is diagnosed on the basis of examination data and histological examination. The treatment is surgical.
Eccrine spiradenoma is a rare benign neoplasm of the skin, histogenetically associated with the intradermal duct. It can develop at any age. 72% of patients are people under the age of 40, 10.8% are children under the age of 10. There is a slight predominance of male patients. Eccrine spiradenoma is characterized by a long course, the average duration of the disease from the moment of the first symptoms to surgical removal of neoplasia is more than 3 years. A case is described in which eccrine spiradenoma existed for 57 years.
Usually the tumors are solitary, sometimes there are multiple neoplasias grouped in one anatomical zone. Neoplasms can be located on any part of the body, except for the soles, palms, nipples, footbed, labia, foreskin, ankle, femoral and wrist joints. Most often, eccrine spiradenomas are localized on the trunk, less often the head and extensor surfaces of the upper and lower extremities are affected. The treatment is carried out by specialists in the field of dermatology and oncology.
The causes of spiradenoma have not been established. Malignancy is observed very rarely and is manifested by the acceleration of the growth of a previously stable or slowly increasing neoplasm. The factors causing the malignancy of eccrine spiradens have not been clarified, while experts point to the lack of connection with the effects of toxic substances, ultraviolet and ionizing radiation.
Macroscopically, an eccrine spiradenoma is an intradermal or subcutaneous nodule ranging in size from a few millimeters to several centimeters. Microscopic examination of the incision reveals a homogeneous whitish or pinkish tissue with brown or reddish inclusions of various sizes. In some eccrine spiradenomas, small cysts with smooth walls and bloody or gelatinous contents are visible.
From the point of view of the structure, the tumor is a cluster of nodules, slightly larger in size than the secretory departments of the eccrine glands. A connective tissue layer – a capsule of neoplasia – is visible between the nodules and the unchanged tissue.
Eccrine heliadenoma is represented by two types of cells. The first type is small monomorphic dark cells with scanty cytoplasm, oval or rounded basophilic nuclei, the second is large polygonal or oval cells with weakly basophilic cytoplasm, light rounded or oval vesicular nuclei. Larger cells often predominate in the tissue of eccrine helidenoma, while the ratio of the two types of cells can vary significantly, including in different parts of the same tumor.
In some eccrine spiradenomes, a third type of cells randomly located in the stroma is revealed. Cells of the third type are oval or elongated, with a light cytoplasm and dark nuclei. Sometimes intermediate variants of cells with signs of the second and third types are seen in the neoplasm tissue.
Taking into account the structural features, there are 6 varieties of eccrine spiracles:
- solid – the most common type, differing in the level of differentiation.
- glandular – small adenoid clusters are visible in the structure of the neoplasm, the stroma is scanty.
- tubular – about 12% of eccrine spiracles have a tubular structure, represented by tubes with a two-layer lining.
- angiomatous – a large number of vessels are microscopically detected.
- cylindromatous is the rarest type (3% of cases), represented by tubular, alveolar and solid structures. Numerous hyaline streaks and droplets are visible in the stroma of such tumors.
The tumor is usually solitary, sometimes there are multiple closely located neoplasias. It is most often localized in the trunk area, the first place in prevalence is occupied by eccrine spiradenomas of the back. The face, upper and lower extremities suffer less often.
Neoplasia is a dense or densely elastic intradermal or subcutaneous node, slightly rising above the surface of the skin. Data on the size of the nodes vary, some authors report that the diameter of the eccrine spiracles ranges from a few millimeters to 2 centimeters, others indicate that the average size of the neoplasm is 3-5 centimeters.
The skin above the tumor may have a normal color or be cyanotic. There are also eccrine spiradenomas of reddish shades. Some neoplasms are dome-shaped nodes with a wide or narrow base. The skin above the node on a wide base is usually pinkish, the skin over the tumor on a narrow base has a bluish or grayish tint.
A distinctive feature of eccrine spiradenomas is mild or moderate soreness when cooled and touched. Patients may also complain of short-term paroxysmal pains that appear for no apparent reason.
Ulceration and increased bleeding of eccrine spiradenomas occur more often after injuries and are observed in about 5% of patients. The current is long. Malignancy is very rare.
The diagnosis is established on the basis of complaints, medical history, examination results, cytological examination of a punctate or a scarification smear. In doubtful cases, a biopsy of the cutaneous element is performed. A typical sign of eccrine spiradenoma is the presence of two types of cells (small dark and larger light) in combination with one of the variants of the characteristic structure of the tumor and immature sinusoidal vessels.
Clinical differential diagnosis of eccrine spiradenomas is carried out with other dermal neoplasias, histological – with the following neoplasias:
- eccrine poroma,
- dermoid cyst,
- epidermoid cyst,
- glomus tumor,
The treatment is surgical. Eccrine spiradenoma is excised within healthy tissues. In some cases, electrosurgical methods of treatment or laser evaporation are used.
The prognosis is favorable. Eccrine spiradenoma has a benign character, does not pose a threat to the life and health of the patient. With incomplete excision, recurrence is possible. Relapses after removal of the newly formed eccrine spiradenoma have not been recorded.