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Benign epithelial tumors



These neoplasms are widespread and, although they can cause significant psychological discomfort, they, as a rule, are not accompanied by any serious consequences. Benign tumors, originating from stratified squamous epithelium, keratinocytes of the hair follicles and the ductal lining of the skin glands, in the process of growth can reproduce the same layered 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 specimens is necessary for diagnosis.

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

Seborrheic keratoses (they are also called senile warts or senile keratoses) have characteristic features. They are round flat coin-shaped plaques, 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 grainy surface. These tumors can leave the impression of warts attached to the skin, which can be removed as a peel. Examining them with a handheld magnifier makes it possible to detect small, round, pore-like stomata, occluded by keratin (a sign necessary to distinguish these pigment formations from melanomas). Occasionally, multiple lesions in seborrheic keratoses are so pronounced (recurrent pigmented spots and warts) that they are regarded as part of the paraneoplastic syndrome, or Leser — Trell symptom (E.Leser, U.Trelat). This symptom can be determined due to the presence of malignant melanoma. It is known that such a 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 Leser – Trell symptom may play a certain pathogenetic role in the development of melanoma.

Exophytic seborrheic keratoses are clearly restricted from the adjacent epidermis tissue. They are constructed 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, a different amount of melanin is found, mostly dark brown. On the surface of seborrheic keratosis, one can see signs of excessive keratin production (hyperkeratosis). In particular, small, keratin-filled cysts (horn cysts) and signs of keratin penetration into the main mass of the tumor (pseudo-horn cysts) are very characteristic (Fig. 25.6). If seborrheic keratosis is subjected to prolonged mechanical irritation or inflammation, epidermization occurs in them (squamous metaplasia). When the epithelium of the hair follicles is involved in the tumor process, seborrheic keratosis can become endophytic in nature. Such varieties are called inverted follicular keratosis.

Black acanthosis (acanthosis nigricans). These are thickened (villous or warty) epidermis neoplasms of black color. Affected skin in the neck, armpits, external genital organs, perineum, anus and inguinal-hip folds. The black thickening indicated is often symmetrical. Black acanthosis is considered to be a diagnostically valuable skin marker of



Fig. 25.6.

Seborrheic keratosis

(basal cell papilloma, senile wart).

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

anyone with a combined benign and malignant neoplasm. According to the nature of the combined process, it is divided into two types. The benign type, which makes up 80% of all cases 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 tumors of the pituitary and pineal body), 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 may be due to the abnormal production of various tumors of factors that stimulate epidermal growth. Thus, in middle-aged or elderly people, this formation is often found simultaneously with a malignant tumor, especially adenocarcinoma of an organ. The occurrence of black acanthosis may precede the appearance of a malignant neoplasm. Therefore, timely diagnosis of this tumor has a great clinical and prognostic value.

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

Fibroepithelial polyp. This is a benign tumor of the skin, the name of which has many synonyms (cutaneous horn acrohordon, squamous papilloma, cutaneous fibrous polyp). Fibroepithelial polyp is one of the most common skin tumors and usually occurs in middle age or in elderly persons in the neck, torso, face, and in the areas of diaper rash (intertriginous dermatitis). A polyp has the appearance of a soft, flesh-colored, saccular or horn-shaped tumor attached to the surface of the skin with a small and usually thin leg. Under the microscope, these tumors are exophytic fibro-vascular protrusions (rods) covered with squamous epithelium. Zones of ischemic necrosis, secondary edema and inflammation can be found in the tumor tissue. These are the results of a torsion of a tumor, clinically very painful and accompanied by circulatory disorders in the pedicle of the neoplasm.

As a rule, fibroepithelial polyps have little clinical significance, although they can sometimes develop in combination with diabetes mellitus and intestinal polyposis. Along with non-cellular nevus (see above) and skin hemangiomas (see below), they often become more numerous during pregnancy.

Epithelial cysts. They are formed by the submerged 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 - products of secretion of the sebaceous glands. Externally, these are intracutaneous or subcutaneous, well-defined, dense and, as a rule, easily displaced nodules. For large sizes, they may have the shape of a flesh-colored dome, becoming painful after a break as a result of injury.

Under a microscope, epithelial cysts are found in these nodules, which are divided into a number of histological types by 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 is filled with keratin layered masses (Fig. 25.7). The hair cyst is surrounded by a wall that resembles the lining of the hair follicle without a granular layer, and is filled with a homogeneous mixture of keratin and lipids. A dermoid cyst resembles an intraepidermal cyst, however, multiple outgrowths that mimic appendages (for example, small hair follicles) are seen outward from the cyst wall. Multiple steatokystoma - a rather rare type of cyst. Its wall resembles the duct of the sebaceous gland, from which there are numerous, as it were, compressed greasy slices. The importance of recognizing such a cyst is due to the dominant type of its inheritance.

Keratoacanthoma This is a rapidly developing tumor, which, externally and under a microscope, may resemble a highly differentiated squamous cell carcinoma, but unlike it spontaneously heals without treatment. Men suffer from keratoacantoma 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 a flesh-colored nodule, dome-shaped with a keratin plug, which fills the crater of the tumor. The diameter of the neoplasm varies from 1 cm to several centimeters. The tumor develops predominantly in the skin of the cheeks, nose, ears and dorsum 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 that, like a collar, encompass a crater, and also in the form of uneven reeds are 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 band) covers the wall of the cyst, layered masses of keratin are visible.

cytoplasm. They synthesize keratin without forming a granular layer. This method of keratinization is found in the 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 call are new and elastic fibers and squeezes them. During this rapid proliferative stage, a small inflammatory response may occur (Fig. 25.8, B). Further, fibrotic tumor stroma joins inflammatory infiltration.

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





Fig. 25.8.

Keratoacanthoma

,

A -

general form

; B -

part of the epidermal dome

.



Tumors of the skin appendages are often single or multiple papules and nodules. Some of them show a tendency to occur in particular areas of the body. For example, the eccranial poroma — a swelling of the ducts of the sweat glands — appears predominantly on the palms and soles. Cylindroma 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, having the appearance of a cap or hat. Such tumors can be inherited according to the dominant type and appear for the first time in early childhood. Despite the possible presence in the tissue of cy-



Fig. 25.9.

Skin Cylinder

(general form),

lindromes foci of piloid (hair-like) differentiation, this tumor also originates from the lot glands. Its parenchyma consists of complexes and layers of basaloid cells (Fig. 25.9), which are connected to each other in the fibrous tissue of the dermis. Syringoma is considered a malformation of the sweat glands, its tumor nature is discussed. As a rule, this formation consists of multiple small brown papules appearing in the lower eyelids. More often women are affected. The syringoma reflects the eccrine ductal type of differentiation, which is defined in small and flask-shaped complexes of the epithelium of the basaloid type (Fig. 25.10, A, B).



Fig. 25.10.

Skin Syringoma

.

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

Trichoepithelioma - a neoplasm originating from the hair follicle. The tumor is inherited according to the dominant type; This multiple translucent papules in the form of a dome, which appear on the face, the surface of the head, neck and upper torso. The tumor parenchyma is a complex of pale pink transparent cells that resemble the upper part of the hair follicle (funnel). In tab. 25.2 summarized the most important clinical and morphological features of the most common benign tumors of the skin appendages.

Table 25.2.

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





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



Fig. 25.11.

Cancer of the skin appendages

, And - the epidermis, struck again.



Fig. 25.11.

Continuation



B - sweat gland cancer with a cirrhosis; B - cancer of trabecular-alveolar structure.

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Benign epithelial tumors

  1. Epithelial tumors
    1. Name a malignant tumor from the surface epithelium: a) sarcoma b) adenoma c) adenocarcinoma d) squamous epithelium e) papilloma The correct answer: d 2. Adenocarcinoma property: a) develops from connective tissue b) develops from glandular epithelium c) organ-specific cancer atipism no d) does not metastasize The correct answer: b 3. The origin of chorionepithelioma: a) the endometrium b)
  2. Epithelial tumors
    Adenomas (adenomatous, or glandular, polyps). They are either small exophytic tumors on the leg (see Chapter 7), or large neoplasms on a broad basis. From 20 to 30% of these tumors occur in people under the age of 40 years and 40-50% in people older than 60 years. Familial predisposition to sporadically developing glandular polyps is well known: in close relatives
  3. Malignant epithelial tumors
    They are called cancer, or carcinoma. General characteristics. 1. It is much more common than all other malignant tumors. 2. Often associated with previous diseases and conditions that are called precancerous. 3. The development of many carcinomas (morphogenesis) is associated with previous changes in the epithelium - hyperplasia, metaplasia, dysplasia. 4. The only pre-cancerous
  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 unrestrained cell proliferation, is distinguished by morphological, biochemical, histochemical and antigenic atypism. Morphological atypism is divided into tissue and cellular. The 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. In terms of incidence among tumors of different localization, lung cancer takes the first place, and the second is stomach cancer. Breast cancer is the most common form of a tumor in women. Basal cell carcinoma of the skin (basal cell carcinoma) is represented by a plaque, knot, or deep
  6. Benign tumors of the ovaries
    Benign ovarian tumors are divided into: • epithelial; • connective tissue. Ovarian epithelial neoplasms usually include: • serous: o smooth-wall; o papillary. • mucinous tumors: o proper cystomas or pseudomucinous cystomas o pseudomyxomas. The main type of connective tissue benign tumor is ovarian fibroma.
  7. Benign tumors of the ovaries
    Benign ovarian tumors are divided into: • epithelial; • connective tissue. Ovarian epithelial neoplasms usually include: • serous: o smooth-wall; o papillary. • mucinous tumors: o proper cystomas or pseudomucinous cystomas o pseudomyxomas. The main type of connective tissue benign tumor is ovarian fibroma.
  8. Benign tumors can be cured by poisons
    Benign tumors are composed of cells that differ from normal cells, mainly only by increased growth. Such tumors are characterized by limited enhanced growth, often covered with a connective tissue capsule, do not germinate into the 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 a rare disease. There are benign and malignant neoplasms. Benign ear tumors include papillomas, fibromas, angiomas, chondromas, osteomas, etc. Of the tumor-like formations should be noted various kinds of cysts (atheroma, dermoid, etc.). Benign tumors are localized mainly in the region of 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 significance. Many benign tumors eventually tend to become malignant. It has been noted that tumors of any degree of differentiation, localized on the lateral wall of the nose, should practically be regarded as potential
  11. BENEFICIAL STOMACH TUMORS
    formed as a result of inflammatory hyperplasia of the mucous membrane. Tumors are fibroepithelial, less often - 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 tumors of the nose include papillomas, fibromas, angiomas and angiofibromas, chondromas, osteomas, neuromas, nevi (pigmented tumors), warts. Some authors attributed to benign tumors and mucous polyps, however, these formations do not have a tumor structure and are inflammatory and allergic hyperplasia of the mucous membrane, the so-called "vocal
  13. Benign laryngeal tumors
    Among benign larynx tumors, fibromas, papillomas, angiomas are more common. Fibroma (fibrous polyp) usually occurs at the free edge of the vocal fold on the border between the front and middle thirds, grows very slowly and more often does not reach large sizes. It has a rounded shape, the base can be wide or in the form of a leg. The histological structure of fibroma is presented
  14. Benign tumors of the pharynx
    The benign tumors of the pharynx include fibroma, papilloma, hairy polyp, angioma, neuroma, neurofibroma, mixed tumors, lipoma, cysts, and pharyngeal goiter. More often than others papillomas and fibromas on a leg meet. Papillomas are usually soft, located on the soft palate and palatine arches, are small and, as a rule, are of little concern to patients. In some cases, papillomas come from
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