Mesothelioma and Asbestos: Thank you for seeing the video, subscribe
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is interesting. Mesothelioma is a rare form of cancer of the
mesothelial surfaces that affects the lining of the lungs (the pleura), the abdominal cavity
(the peritoneum), or the envelope of the heart (the pericardium).
We will talk about mesothelioma PLEURAL, which is the most frequent:
Pulmonary mesothelioma is caused by exposure to mineral fibers (such as asbestos, or erionite).
The clearly identified carcinogenic agent, ASBESTOS.
Male occupational disease. Experimental interest: animal experiments
Difficult anatomopathologic diagnosis Immunohistochemistry is essential
Prognosis is bleak. Disappointing treatments: there are many therapeutic
approaches.
Histological reminders:
Mesothelium is a single layer of flattened cells forming the lining of the body cavities:
peritoneal, pleural, pericardial.
The mesothelial cell: The exact original cell of malignant Mesothelioma
is not clearly known. It is commonly believed that these tumors
originate from surface mesothelial cells. Experimental data suggests that they can originate
from submelothelial cells that can differentiate in several directions.
The functions of the mesothelial cell: Key Roles in: Surface lubrication (slippery,
non-adhesive and protective). The transport of fluids and cells through
the serous cavities The presentation of antigens
inflammation Cell adhesion.
The various mesotheliomas:
Pleural seat: in 70% of cases, the latency period between exposure, and the onset of
the disease 20-30 years. Peritoneal seat: in 30%, latency period: between
30 and 40 years. Other seats are more rare: testicular vaginal,
pericardium. Other factors incriminated in mesothelioma:
Simian virus SV40 implicated as a cofactor in the development of mesothelioma.
Polio vaccine used between 1955 and 1963 contaminated with SV 40.
SV40 involved in the occurrence of cancers
in animals.
Smoking: For some, does not seem to increase the
risk of mesothelioma but risk multiplicative for others.
particular case Use of asbestos in Kent brand cigarette
filters during some of its early years of production in the 1950s: some cases of mesothelioma
have resulted. Other: abdominal radiotherapy, chronic peritonitis,
erionite (Turkey) incriminated in peritoneal mesothelium
Development of peritoneal mesothelioma:
Asbestos fibers from the lung transported to the abdomen and associated organs through
the lymphatic system. Mineral fibers can be deposited in the intestine
after ingestion of contaminated sputum.
Anatomopathological diagnosis: Diagnosis is difficult because of the problem
of atypical mesothelial hyperplasia. There is no reliable histological criterion
for separating lesions that may be mesothelioma in situ from benign, atypical reaction lesions.
Term "Atypical mesothelial hyperplasia" recommended for purely surface mesothelial proliferations
that may or may not be malignant. Major criterion for the diagnosis of mesothelium
and mesothelial reactional hyperplasia is the presence of stromal invasion.
Cytology report: Atypical mesothelial proliferation recommending a biopsy to affirm, or rule out
the possibility of a mesothelioma. Atypical Mesothelial Hyperplasia: There is
no currently marketed immuno-histochemical marker that differentiates benign and malignant
cells.
Morphological presentations:
Work support: WHO 2004 classification of pleural tumors:
Several morphological aspects Epithelioid, which is the most common
Sarcomatoid rare, 32 cases reported in
the literature since 2006 Desmoplastic.
Biphasic.
Differential morphological diagnosis of diffuse malignant mesothelioma
Metastases in the pleura: secondary to A carcinoma, sarcoma, lymphoma,
malignant melanoma ... Primary diffuse pleural sarcoma:
Angiosarcoma, haemangioendothelioma epithelioide, synovial sarcoma, other sarcomas
... Primary or metastatic thymic tumors ...
Small round cell tumors desmoplastic and Ewing sarcoma
Primary localized pleural tumors. Localized malignant mesothelioma,
solitary fibrous tumor, sarcomas, well-differentiated papillary pleural mesothelioma, adenomatoid
tumor.
This slide shows the histological aspect of epithelioid mesothelioma.
immunohistochemistry Recommended panel
1.Positive markers for the diagnosis of mesothelioma: calretinin
Antigen 1 of the Wilms tumor (W T 1) Anti-Epithelial Membrane Antigen (E M A)
Cytokeratin 5/6 (CK 5/6), Anti D2 40,
anti-mesothelin.
2. Negative Markers: Thyro id transcription factor 1: T T F 1
Ber EP 4, antiB72-3, anti-MOC-31, anti EMA Carcinoembryonic Antigen: A C E
Anti-estrogen receptor, and progesterone (female).
This slide shows the histological aspect of a sarcomatoid mesothelioma.
Finally, this slide shows the histological aspect of desmoplastic mesothelioma.
Prognosis: CLASSIFICATION T NM OF PLEURAL TUMORS: TNM
(International Mesothelioma Interest Group) (Rusch 1995, updated by o m s in 2004)
Severe short-term 12 to 18 months. Five-year survival rate of less than 5%.
Non-epithelioid subtype (unfavorable prognostic factor).
Prevention c Know the products that may contain asbestos:
Here is the list of CLASSIFICATION OF PRODUCTS CONTAINING ASBESTOS:
1. Bulk crude asbestos: Wadding, Flockings, Insulation, Thermal and acoustic protection
2. Asbestos in powder, mineral products (except asbestos-cement): Plasters, Plasters for plaster,
Plaster for fire protection, Mortars for glues, Mortars for fire protection, Refractory mortars,
Powder for molding
3. Asbestos in liquids or pastes: Glues, Plasters, Sealants, Foams, Joint paste, Paints
4. Asbestos in sheets or plates: Cardboard, Partition, Shells, Suspended ceilings, Sheets,
Felt, Filters, Panels, Paper, Plates
5. Asbestos woven or braided: Bands, Ruffles, Cords, Blankets, Mattresses, Glands, Curtains,
Ribbons, Fabrics, Braids, Clothes
6. Asbestos in a resin or a plastic material: Clutch,
Brakes, Electrical insulators, Gaskets, Composite materials, Plastic, Foams, Stair nosings,
Wall tiles, Slab or roller floorings 7. Asbestos-cement: Sheaths, Cladding, Pipes,
Partition, Roof elements, Sheath, Plate, Roofing plates, Shelves, Pipes, Vetures
8. Asbestos in black products: Bituminous shingles, Bitumen, Bituminous adhesives, Corrosion-resistant
coating (cars, wagons), Waterproofing protective coating (locks, ponds, channels ...), Roof
sealing, Sealants, Road surfacing
9. Asbestos in materials
and equipment: Boilers, Fire dampers, Ovens, Ovens, Doors, Elevator doors, Radiators