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Benign Epithelial Tumors

These neoplasms are widespread and, although they can cause significant psychological discomfort, nevertheless, as a rule, they are not accompanied by any serious consequences. Benign tumors originating from the stratified squamous keratinizing epithelium, keratinocytes of the hair follicles and ductal lining of the skin glands, in the process of growth can reproduce the same multilayer structures as those from which they arise. Clinically, they can often be confused with malignant tumors, especially when they are pigmented or inflamed, so a histological examination of biopsy samples is necessary to establish a diagnosis.

Seborrheic keratoses. These are very common epidermal tumors, which more often appear in middle age or in the elderly. They occur spontaneously and can be especially numerous on the skin of the body, the skin of the limbs, head and neck can be affected. In people of a non-European race, multiple small neoplasms on the face are called papular black dermatosis (dermatosis papulosa nigra).

Seborrheic keratoses (also called senile warts or senile keratoses) have characteristic signs. They are round flat plaques in the shape of a coin, the diameter of which varies from a few millimeters to several centimeters. Such papules have a uniform dark brown color and, as a rule, a velvety or granular surface. These neoplasms may give the impression of warts attached to the skin, which can be removed as a crust. Inspecting them with a handheld magnifier reveals small round pore-shaped stomata clogged with keratin (a sign necessary to distinguish these pigmented formations from melanomas). Occasionally, multiple lesions in seborrheic keratoses are so pronounced (recurring pigmented spots and warts) that they are regarded as part of the paraneoplastic syndrome, or a symptom of Lezer-Trel (E. Leser, U. Trelat). This symptom can be determined in connection with the presence of malignant melanoma. It is known that such melanoma can produce a transforming growth factor-a (a factor closely related to epidermal growth factor). Since this factor interacts with receptors on basal keratinocytes, it is believed that seborrheic keratoses in individuals with Lezer-Trel symptom can play a certain pathogenetic role in the development of melanoma.

Exophytic seborrheic keratoses are clearly limited from adjacent epidermal tissue. They are built from complexes consisting of small cells that are similar to the cells of the basal layer of the normal epidermis. In the cytoplasm of basaloid cells, various amounts of melanin are found, mainly of a dark brown color. On the surface of seborrheic keratoses, you can see signs of excessive keratin production (hyperkeratosis). In particular, small keratin-filled cysts (horny cysts) and signs of keratin penetration into the bulk of the tumor (pseudo-horny cysts) are very characteristic (Fig. 25.6). If seborrheic keratoses are subjected to prolonged mechanical irritation or inflammation, epidermis (squamous metaplasia) occurs in them. When the epithelium of the hair follicles is involved in the tumor process, seborrheic keratoses can acquire an endophytic growth pattern. Such varieties are called inverted follicular keratoses.

Black acanthosis (acanthosis nigricans). These are thickened (villous or warty) neoplasms of the epidermis, having a black color. The skin is affected in the neck, armpits, external genitalia, perineum, anus, and inguinal-femoral folds. Said black thickening is often symmetrical. Black acanthosis is believed to be a diagnostically valuable skin marker of ca-

Fig. 25.6.

Seborrheic keratosis

(basal cell papilloma, senile wart).

A is a general view of the tumor in the form of a plaque; B - a detail of the structure of the tumor; black masses in the stroma and parenchyma of the neoplasm are deposits of melanin.

any combined benign and malignant neoplasms. According to the nature of the combined process, it is divided into two types. The benign type, which accounts for 80% of all observations of black acanthosis, develops gradually and usually occurs in childhood or during puberty. It can develop as an autosomal dominant disease with varying degrees of penetrance; secondary process in obesity or endocrine disorders (in particular, in pituitary and pineal tumors), as well as in diabetes mellitus; one of the manifestations of rare congenital syndromes. Now about the malignant type. Like seborrheic keratosis (see above), black acanthosis can be the result of abnormal production of factors stimulating epidermal growth by various tumors. So, in middle-aged or elderly people, this formation often occurs simultaneously with a malignant tumor, especially an adenocarcinoma of any organ. The appearance of black acanthosis may precede the appearance of a malignant neoplasm. Therefore, timely diagnosis of this neoplasm has great clinical and prognostic value.

Both types of black acanthosis have similar histological features. The outer line of the epidermis is severely convoluted due to numerous and repeated elevations and depressions. The zones of epidermal hyperplasia, expressed to varying degrees, are determined, as well as areas of hyperkeratosis and minor hyperpigmentation (but not melanocytic hyperplasia) of the cells of the basal layer.

Fibroepithelial polyp. This is a benign skin tumor, the name of which has many synonyms (skin horn, acrochordon, squamous papilloma, skin fibrous polyp). Fibroepithelial polyp is one of the most common skin neoplasms and usually occurs in middle age or in elderly people on the neck, trunk, face, and also in diaper rash zones (intertriginous dermatitis). The polyp has the appearance of a soft, flesh-colored, saccular or horn-shaped tumor attached to the surface of the skin with the help of a small and usually thin leg. Under the microscope, these tumors are exophytic fibro-vascular protrusions (rods) covered with squamous epithelium. In the tumor tissue, zones of ischemic necrosis, secondary edema and inflammation can be detected. These are the results of a torsion of the tumor, which is clinically very painful and accompanied by impaired blood supply in the leg of the neoplasm.

As a rule, fibroepithelial polyps are not of great clinical significance, although they can sometimes develop in combination with diabetes mellitus and intestinal polyposis. Along with non-extracellular nevus (see above) and skin hemangiomas (see below), they often become more numerous during pregnancy.

Epithelial cysts. They are formed during the submersible nature of growth and the formation of cystic cavities from the structures of either the epidermis or the lining of the hair follicle.
Cystic cavities are usually filled with keratin and various amounts of other components containing lipids - the secretion products of the sebaceous glands. Outwardly, these are intradermal or subcutaneous, well-defined, dense and, as a rule, easily displaced nodules. With large sizes, they can take the form of a flesh-colored dome, become painful after rupture as a result of an injury.

Under the microscope, in these nodules, epithelial cysts are detected, which are divided into a number of histological types according to the structure of the walls. The intraepidermal (epidermal, epidermal inclusion) cyst is surrounded by a wall that is almost identical in structure to the epidermis and filled with layered keratin masses (Fig. 25.7). The hair cyst is surrounded by a wall resembling a lining of a hair follicle without a granular layer, and is filled with a homogeneous mixture of keratin and lipids. A dermoid cyst is similar to an intraepidermal cyst, however, multiple outgrowths imitating the appendages (for example, small hair follicles) are visible outside the cyst wall. Multiple steatocystoma is a fairly rare type of cyst. Its wall resembles the duct of the sebaceous gland, from which numerous, as if squeezed, sebaceous lobes originate. The importance of recognizing such a cyst is due to the dominant type of its inheritance.

Keratoacanthoma. This is a rapidly developing neoplasm that, externally and under a microscope, may resemble highly differentiated squamous cell carcinoma, but unlike it, spontaneously heals without treatment. Men suffer from keratoacanthoma more often than women, usually after 50 years. As a rule, in individuals of the European race, this tumor occurs in open areas of the skin. Keratoacanthoma manifests itself in the form of a flesh-colored nodule with a domed shape with a keratin plug that fills the tumor crater. The diameter of the neoplasm varies from 1 cm to several centimeters. The tumor develops mainly in the skin of the cheeks, nose, ears and back surface of the hands.

Histologically, keratoacanthoma is characterized by the presence of a crater filled with keratin and surrounded by proliferating epithelial cells (Fig. 25.8, A, B). The latter form solid structures, which, like a collar, cover the crater, as well as in the form of uneven tongues immersed in the dermis. These epithelial cells are relatively large, have signs of mild atypia and eosinophilic

Fig. 25.7.

Epidermal skin cyst

. Over the epidermis, which (in the form of a black strip) covers the cyst wall, layered masses of keratin are visible.

cytoplasm. They synthesize keratin without forming a granular layer. This keratinization method is found in a normal hair follicle and hair cyst. This suggests that keratoacanthoma is a derivative of the follicular epithelium. At an early stage of development, the tumor infiltrates the coll are new and elastic fibers and compresses them. During this rapid proliferative stage, a small inflammatory response may occur (Fig. 25.8, B). Subsequently, tumor stromal fibrosis joins the inflammatory infiltration.

Tumors of the appendages of the skin. Hundreds of benign neoplasms arising from skin appendages are known. Some appendageal skin tumors appear as part of multiple malformations. In some cases, these neoplasms serve as certain markers indicating the presence of malignant tumors of the internal organs.

Fig. 25.8.



A -

general form

; B -

part of the epidermal dome


Tumors from the appendages of the skin are often single or multiple papules and nodules. Some of them show a tendency to occur in special areas of the body. For example, an ectopic pore - a tumor of the ducts of the sweat glands - appears mainly on the palms and soles. The cylinder has an apocrine type of differentiation, usually occurs on the forehead or scalp. The fusion of tumor nodes can lead to the formation of a turban tumor, which looks like a cap or hat. Such neoplasms can be inherited in a dominant manner and first appear in early childhood. Despite the possible presence of cy-

Fig. 25.9.

Skin cylinder

(general form),

Lindroma of foci of piloid (hair-like) differentiation, this tumor also originates from the lotus glands. Her parenchyma consists of complexes and layers of basaloid cells (Fig. 25.9), which connect to each other in the fibrous tissue of the dermis. Syringoma is considered a malformation of the sweat glands, its tumor nature is being discussed. As a rule, this formation is a plurality of small brown papules that appear in the lower eyelid region. More often women are affected. Syringoma reflects an eccrine ductal variety of differentiation, which is determined in small and bulbous complexes of the basaloid type epithelium (Fig. 25.10, A, B).

Fig. 10/25.

Syringoma of sweat glands of the skin


A is a general view of a tumor located in the dermis; B - detail of the structure,

Trichoepithelioma is a neoplasm originating from the hair follicle. A tumor is inherited by a dominant type; these are multiple translucent dome-shaped papules that appear on the face, surface of the head, neck and upper body. Tumor parenchyma is a complex of pale pink transparent cells resembling the upper part of the hair follicle (funnel). In the table. 25.2 summarizes the most important clinical and morphological features of the most common benign tumors of the appendages of the skin.

Table 25.2.

Clinical and morphological features of the most common tumors of the appendages of the skin

Along with these benign neoplasms, although very rarely, their malignant analogues, for example, cancer from the sebaceous glands, are found. It is known that it develops from the glands of the cartilage of the eyelid (meibomian glands; H. Meibom) and can produce metastases in various organ systems. Eccrine and apocrine carcinomas of the skin can often be confused with metastases of adenocarcinoma or scirra due to the very characteristic glandular structure of their tissue (Fig. 25.11, A, B, C).

Fig. 11/25.

Appendage Cancer

, A - epidermis, affected secondarily.

Fig. 11/25.


B - cancer of sweat glands with cirrhosis; B - cancer of the trabecular-alveolar structure.

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Benign Epithelial Tumors

  1. Epithelial tumors
    1. What is a malignant tumor from the integumentary epithelium: a) sarcoma b) adenoma c) adenocarcinoma d) squamous epithelium e) papilloma Correct answer: d 2. Property of adenocarcinoma: a) develops from connective tissue b) develops from glandular epithelium c) organ-specific d ) no atypism e) does not give metastases Correct answer: b 3. The origin of chorionepithelioma: a) endometrium b)
  2. Epithelial tumors
    Adenomas (adenomatous, or glandular, polyps). They are either small exophytic tumors on the peduncle (see chapter 7), or large neoplasms on a broad base. From 20 to 30% of such tumors occurs in people under the age of 40 years and 40-50% in people over 60 years of age. A familial predisposition to sporadically developing glandular polyps is well known: among immediate relatives
  3. Malignant Epithelial Tumors
    They are called cancer, or carcinoma. General characteristics. 1. Meet much more often than all other malignant tumors. 2. Often associated with previous diseases and conditions, which are called precancerous. 3. The development of many carcinomas (morphogenesis) is associated with previous changes in the epithelium - hyperplasia, metaplasia, dysplasia. 4. The only precancerous
  4. General information about tumor growth. Epithelial tumors without specific localization
    A tumor is a pathological process or substrate, represented by a newly formed tissue, in which changes in the genetic apparatus of cells lead to dysregulation of their growth and differentiation. The tumor is characterized by uncontrolled cell multiplication, characterized by morphological, biochemical, histochemical and antigenic atypism. Morphological atypism is divided into tissue and cell. First
  5. Epithelial organ-specific tumors. Cancer of individual organs
    Organ-specific tumors are tumors that develop in certain organs and retain their morphological and functional features. According to the frequency of occurrence among tumors of various localization, lung cancer is the first, and gastric cancer is the second. Breast cancer is the most common tumor in women. Basal cell skin cancer (basal cell carcinoma) is represented by a plaque, nodule or deep
  6. Benign Ovarian Tumors
    Benign tumors of the ovaries are divided into: • epithelial; • connective tissue. Epithelial neoplasms of the ovaries usually include: • serous: o smooth-walled; o papillary. • mucinous tumors: o proper cystomas or pseudo-mucinous cystomas o pseudomyxomas. The main type of connective tissue benign tumor is ovarian fibroma.
  7. Benign Ovarian Tumors
    Benign tumors of the ovaries are divided into: • epithelial; • connective tissue. Epithelial neoplasms of the ovaries usually include: • serous: o smooth-walled; o papillary. • mucinous tumors: o proper cystomas or pseudo-mucinous cystomas o pseudomyxomas. The main type of connective tissue benign tumor is ovarian fibroma.
  8. Benign tumors are cured by poisons
    Benign tumors consist of cells that differ from normal ones mainly only by enhanced growth. Such tumors are characterized by limited enhanced growth, are often covered with a connective tissue capsule, and do not grow into surrounding tissues. In rare cases, benign tumors reach gigantic sizes (up to 10-20 kg), but even then they do not spread throughout the body. Clinically
  9. Benign ear tumors
    Ear tumors are rare diseases. There are benign and malignant neoplasms. Benign ear tumors include papillomas, fibromas, angiomas, chondromas, osteomas, etc. Of the tumor-like formations, various cysts (atheromas, dermoids, etc.) should be noted. Benign tumors are localized mainly in the outer ear.
  10. Benign tumors
    Among benign tumors of the nose and paranasal sinuses, papillomas, adenomas, vascular tumors, chondromas, and osteomas are of the greatest clinical importance. Many benign tumors show a tendency to malignancy over time. It is noted that tumors of any degree of differentiation, localized on the lateral wall of the nose, should practically be regarded as potential
  11. Benign Gastric Tumors
    formed as a result of inflammatory-reactive hyperplasia of the mucosa. Tumors are fibroepithelial, less commonly fibroids, fibroids, neuromas, angiomas, lipomas, hemangiomas. Polyps - conditionally benign tumors, are single or multiple formations located mainly in the antrum
  12. Benign Nasal Tumors
    Benign nasal tumors include papillomas, fibromas, angiomas and angiofibromas, chondromas, osteomas, neuromas, nevi (pigmented tumors), warts. Some authors referred to benign tumors and mucous polyps, however, these formations do not have a tumor structure and represent inflammatory and allergic hyperplasia of the mucous membrane, the so-called "singing
  13. Benign laryngeal tumors
    Among benign tumors of the larynx, fibromas, papillomas, and angiomas are more common. Fibroma (fibrous polyp) usually occurs at the free edge of the vocal fold at the border between the anterior and middle thirds, grows very slowly and often does not reach large sizes. It has a rounded shape, the base can be wide or in the form of legs. The histological structure of fibroma is presented
  14. Benign pharyngeal tumors
    Benign pharyngeal tumors include fibroma, papilloma, hairy polyp, angioma, neurinoma, neurofibroma, mixed tumors, lipoma, cysts, pharyngeal goiter. More often than others, papillomas and fibromas on the leg are found. Papillomas are usually soft, located on the soft palate and palatine arches, are small in size and, as a rule, bother the patients a little. In some cases, papillomas come from
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