CONNECTIVE TISSUE TUMORS
1. BENIGN CONNECTIVE TISSUE TUMORS
A/ Fibroids
These are nodular, well-circumscribed lesions located in the dermis, the corium of the mucous membranes or certain parenchymas, made up of adult connective tissue, rich in collagen.
B/Lipomas
These tumors, generally encapsulated, single or multiple, are composed of mature fat cells grouped in lobules, sometimes associated with a significant fibrous or vascular component (fibrolipoma, angiolipoma). They are usually located in the subcutaneous tissue.
C/Angiomas
Angiomas or lymphangiomas are most commonly considered to be
hamartomas and not as tumors. Angiomatoses (multiple vascular lesions) are observed in certain complex congenital diseases (vonHippel-Lindau disease for example).
D/ Myomas
Benign tumors of muscle tissue are of unequal frequency. Benign tumors of smooth muscle or leiomyomas are common. These well-circumscribed, sometimes large tumors are located in the uterus (improperly referred to as “fibroma”), the digestive musculature and the dermis.
Benign tumors of striated muscle or rhabdomyomas are exceptional.
(cardiac rhabdomyoma of tuberous sclerosis of Bourneville).
E/ Chondromas
These are nodular tumors made of well-differentiated cartilaginous tissue. They are
develop mainly in the small bones of the hands and feet. Ollier’s disease is a chondromatosis characterized by multiple chondromas.
F/Osteomas
These are rare lesions, made up of mature bone, mainly affecting the bones of the face. Their tumoral nature is, moreover, debated.
2. MALIGNANT CONJUNCTIVE TUMORS: SARCOMAS
A/ DEFINITION
Sarcomas are malignant growths whose cells resemble
those of connective tissues (common connective tissue fibroblasts or specialized connective tissue cells).
B/ General characteristics
Sarcomas are much rarer than carcinomas. Clinically, sarcomas often develop very rapidly and spontaneous progression is generally rapidly unfavorable. This is marked by rapid loco-regional extension accompanied by compression phenomena and the frequency of hematogenous metastases.
The classification of connective tissue tumors theoretically follows simple rules. The
The name of the tumor consists of a prefix designating the histological type and a suffix “oma” if it is a benign tumor, “sarcoma” if it is a malignant tumor (. We will emphasize that the international classification
(soft tissue tumors – WHO 2020) is based on the type of tissue reproduced by the tumor and not the histogenesis.
C/ Macroscopic aspects
The appearances vary depending on the topography and the tumor type. This one
may present as a whitish, soft, “encephaloid” tissue, infiltrating and destroying the organ and adjacent tissues or often constitutes a firm mass, with polycyclic contours, pushing back the surrounding tissues.
D/ Microscopic aspects
General histological characteristics are difficult to identify due to the large
polymorphism of these tumors.
Histopathological grading is based on differentiation, number of mitoses and the presence or absence of necrosis.
Sarcomas are known to be difficult to diagnose. Two extreme cases can be
to present :
– it can be very difficult to make a definitive diagnosis of malignancy
some very well differentiated sarcomas, liposarcomas or chondrosarcomas in particular. In these cases, anatomo-radio-clinical confrontation is essential. Rarely, only the evolution will allow to affirm with certainty the benign or malignant character of the tumor.
– conversely, undifferentiated sarcomas also pose problems
difficult diagnostics. Different complementary techniques immunohistochemistry,
electron microscopy, cytogenetics, molecular biology) may prove to be
essential to confirm the tumor type.
In practice, two main groups of sarcomas are distinguished:
Soft tissue sarcomas
Sarcomas of skeletal tissues
I- Soft tissue sarcomas
1. Liposarcomas
These tumors are ubiquitous but are more frequently encountered in the limbs, the retroperitoneal space, and rarely the oral cavity. Histologically, all degrees of differentiation are observed, from poorly differentiated spindle cell tumors containing rare lipoblasts to very well-differentiated tumors, difficult to distinguish from lipomas.
The evolution, of variable duration, is always marked by the appearance of relapses
local and metastases.
2. Rhabomyosarcomas
The adult form develops in striated muscle. It is a fusiform proliferation presenting a more or less marked muscular differentiation (double striation).
The evolution is short with early appearance of metastases.
Embryonic rhabdomyosarcoma in children is ubiquitous, developing outside of striated muscles. Several histological types with different prognoses are classically described (botryoid, alveolar, embryonic).
3. Leiomyosarcomas
Among the most frequent locations, we will remember the dermis, the uterus and the digestive tract. The fasciculated proliferation is also composed of spindle cells with smooth muscle differentiation.
4. Angiosarcomas
The morphological aspects are very varied. In addition to metastatic dissemination, the evolution is often burdened by massive hemorrhages. Kaposi’s sarcoma is
a form of angiosarcoma frequently seen in AIDS.
5. Fibrosarcomas
Ubiquitous, fibrosarcoma is a fasciculated tumor, made of spindle cells resembling fibroblasts, arranged in more or less abundant collagen fibers and sometimes adopting a fasciculated architecture.
The evolution is dominated by local recurrences and especially hematogenous metastases.
Differential diagnosis:
A number of proliferations morphologically close to fibrosarcomas present a completely different evolution:
II. SARCOMAS OF SKELETAL TISSUES
1. Osteogenic sarcomas (osteosarcomas)
It is the most common malignant tumor of bone tissue. Macroscopically, the
The tumor is metaphyseal (femur, tibia, humerus and maxilla). During its evolution, it destroys the cortex, exceeds the periosteum and develops in the soft parts (radiological appearance of “grass fire”).
Histologically, it is a fusiform proliferation dotted with foci of tumor osteogenesis. The evolution is rapid with local extension (responsible for pain, spontaneous fractures) and metastases (lung)
2. Chondrosarcomas
A tumor in adults, it develops spontaneously or on a pre-existing lesion (girdle enchondroma), mainly in the flat bones (ribs, girdles) or in the metaphysis of the long and maxillary bones.
Macroscopically, the lesion appears lobulated, pearly, bluish in appearance.
On microscopic examination, it reproduces, depending on its degree of differentiation, an appearance of more or less elaborate cartilaginous tissue. The diagnosis of malignancy can be difficult to make in very well differentiated forms.
Other Tumors
1. TUMORS OF HEMOLYMPHATIC TISSUES
Malignant lymphomas are solid lymphoid tumors.
B and T lymphoid tumor proliferations
Their precise classification is carried out according to clinical, morphological criteria,
immunological, cytogenetic, molecular.
Acute lymphoid leukemias affect children and young adults
Chronic lymphocytic leukemias and lymphoproliferative syndromes are characterized by blood and bone marrow invasion by peripheral lymphoid cells at different stages of differentiation and maturation: B or T CLL (rarer), Waldenström’s disease (with monoclonal peak of serum IgM), heavy chain disease, hairy cell leukemia.
Myeloma is a plasma cell tumor, located in the bone, often accompanied by a serum monoclonal peak (IgA, IgG)
Non-Hodgkin’s malignant lymphomas
They develop in any lymphoid territory but also affect the mucous membranes, the thyroid, the salivary glands, etc.
Different classifications are proposed including cytological criteria,
architectural, phenotypic and cytogenetic.
Hodgkin’s malignant lymphomas are characterized by cellular proliferation
polymorphic. This is composed of tumor cells described by Sternberg,
pathognomonic of the disease, and small non-tumor cells (lymphocytes,
plasma cells, eosinophilic polymorphonuclear cells, histiocytes) in varying proportions.
The currently used Lukes-Rye classification distinguishes 4 histological types of Hodgkin’s disease.
2. MELANIC TUMORS
Developed from the cells that produce the melanin pigment, they are located
mainly at the skin level, more exceptionally on the choroid, the oral and aerodigestive mucosa. Benign melanotic tumors are frequent, malignant melanotic tumors remain rare. However, the frequency of malignant melanomas, whose prognosis is particularly poor, is constantly increasing.
a) The naevocellular nevus especially the lips
Moles are formed by a proliferation of nevus cells that group together in clusters of 5 to 20 cells: the “thecae”. Moles are classified into:
Junctional nevus: the thecae are located at the level of the basal layer of the epidermis.
Dermal nevus: the cellular thecae are located in the dermis.
Mixed or compound nevus: it has the aspects of the two previous types.
b) Malignant melanotic tumors: melanomas
These tumors can develop on a pre-existing mole, but much more often they appear on healthy malpighian skin or mucosa. These tumors are exceptional in children before 15 years of age, more frequent after 45 years of age. Exposure to the sun during childhood and adolescence constitutes a risk factor for the occurrence of malignant melanomas.
The most common forms develop in two stages:
– first intra-epidermal “horizontal” extension of cell proliferation
naevic.
– then a “vertical” extension. The proliferation penetrates into the dermis, extends in
depth and can then give rise to metastases.
3. TUMORS OF THE NERVOUS SYSTEM
a) Neuromas or schwannomas
These are tumors corresponding to a proliferation of Schwann cells of the nerve sheath , occurring mainly in middle-aged adults. They are encapsulated tumors, appended to a nerve, with a good prognosis after excision.
b) Neurofibromas
In these tumors, proliferation of Schwann cells is associated with proliferation of fibroblastic cells and connective fibers.
These tumors can be multiple and be part of neurofibromatoses.
CONNECTIVE TISSUE TUMORS
Wisdom teeth can cause infections if not removed.
Dental crowns restore the function and appearance of damaged teeth.
Swollen gums are often a sign of periodontal disease.
Orthodontic treatments can be performed at any age.
Composite fillings are discreet and durable.
Composite fillings are discreet and durable.
Interdental brushes effectively clean tight spaces.
Visiting the dentist every six months prevents dental problems.