respiratory system pathology final

Respiratory System

Anatomy

Respiratory Epithelium

Respiratory epithelium

Respiratory epithelium histology

Histologic review

Alveoar epithelium

Histologic review

Lung Cancer-Lung cancer is currently the most frequent diagnosed major cancer in the world.

-The most common cause of cancer mortality worldwide.

-Occurs most often between 40-70 Y o

Etiology and Pathogenesis:

*Tobacco smoking:80% occurs in active smokers.

* Industrial hazards:Asbestos,arsenic,uranium..

*Air pollution.

*Molecular Genetics:K-RAS, MET, ALK, EGFR.

*Precursor Lesion:

Squamous dysplasia and carcinoma in situ.

Atypical adenomatous hyperplasia and Adeno carcinoma in situ

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia

Lung Cancer

• WHO Classfication

-Malignant Epithelial Tumors.

-Mesenchymal Tumors.

-Benign Epithelial Tumors.

-Lymphoproliferative Tumors.

-Miscellaneous Tumors.

-Metastatic Tumors.

Malignant Epithelial Tumors

• - Non small cell carcinoma:

• *Adenocarcinoma.

• *Squamous cell carcinoma.

• *Adenosquamous carcinoma.

• *Large cell carcinoma(un differentiated carcinoma).

• -Small cell carcinoma(neuroendocrine carcinoma)

• -Salivary gland carcinoma:adenoid cystic carcinoma and mucoepidermoid carcinoma.

Adenocarcinoma-Most prevalent non small cell carcinoma.

-most in females and in male non smokers.

Most commonly peripheral.

-Often involve pleura.

-Blood vessels invasion is common at the time of diagnosis.

-Grow more slowly than squamous cell carcinoma, but tend to metastasize widely and earlier.

-Metastasis :brain (often only site), bone, liver..

Gross description:

-Adenocarcinoma is present as poorly circumscribed gray-yellow peripheral lesion.

Adenocarcinoma gross

Adenocarcinoma gross

This peripherally located adenocarcinoma contain a large area of mostly central scarring with anthracoticpigmentation

Adenocarcinoma development

-Atypical adenomatous hyperplasia.

-Carcinoma in situ.

-Adenocarcinoma.

Microscopic Description

Adenocarcinoma is an invasive malignant epithelial tumor with glandular differentiation or mucin production by the tumor cells.

-Adenocarcinoma grow in various patterns, including acinar, lepidic, papillary, micropapillary, and solid with mucin formation.

Acinar pattern

Lepidic pattern

Adenocarcinoma

Mucious subtype Solid pattern

Squamous cell carcinoma

Second most common form of lung carcinoma.

-Most common in male.

-Strong association with smoking.

-Most are central (segmental bronchi) and present as hilar or perihilarmasses.

Generally larger than other lung carcinomas at diagnosis, grow more rapidly but tend to metastasize later.


-Mass arising centrally in the lung.

-Obstructing the right main bronchus.

-Firm mass with pale white to tan cut surface


Squamous cell carcinoma have aspecial tendency to undergo necrosis with cavitation

Squamous cell carcinoma development

-Squamous Cell Metaplasia.

-Squamous Cell Dysplasia.

-Squamous Cell Carcinoma in situ.

-Invasive Squamous Cell Carcinoma.


-Sheets or islands of large polygonal malignant cells with Keratinization and /or intercellular bridges.

Keratinization may take the form of squamous pearls or individual cells with markedly eosinophilic dense cytoplasm.

-These Features are prominent in well differentiated tumors, but not extensive in moderately differentiated ,and focally seen in poorlydifferentiated tumors.


Squamous cell carcinoma with keratinization and necrosis


Nests of Polygonal cells with pink cytoplasm and Distinct cell borders and keratin pearls


Squamous cell carcinoma with intercellular bridges

Neuroendocrine Tumors

-Diffuse Idiopathic pulmonary neuroendocrine cell hyperplasia.

-Tumorlet.

-Typical carcinoid.

-Atypical carcinoid.

- Small cell carcinoma.

- Large cell neuroendocrine carcinoma

Carcinoid Tumors

-Well differentiated (low grade) neoplasms with neuroendocrine differentiation, divided into Typical and Atypical carcinoids.

-Represent 1-5% of, lung Tumors.

-Most Patients are <40, female.

-Most arise centrally ,as fingerlike or spherical polypoid masses that commonly project into the bronchial lumen.

-Peripheral tumors are solid and nodular.

Carcinoid tumor

Carcinoid are usually well circumscribed, round to oval masses filling up the bronchial lumen,and the overlying bronchial mucosa is usually intact.

Cut surface is yellow-gray.

Carcinoid tumor Gross


-Neuroendocrine growth pattern (organoid, trabecular, rosette formation , nested) or pseudo glandular and papillary growth.

-Tumor cells are uniform, polygonal shape, round to oval nuclei with salt and pepper chromatin, along with moderate eosinophilic cytoplasm.

-Typical carcinoid have less than 2 mitosis per 10 hpf.

-Atypical carcinoid show more mitotic activity ,pleomorphism, prominent nucleoli, lymphatic invasion.

carcinoid

Trabecular pattern of growth Solid pattern of growth

The tumor cells have small rounded ,uniform, nuclei with salt and pepper chromatin, along with moderate eosinophilic cytoplasm.

carcinoid

Hydatid Cyst

Echinococcal cyst of lung.

-Echinococcus granulosus are most common in liver ,5-15%occur in lung.

-Human become infected through ingestion parasite eggs in contaminated food, water or soil or through direct contact with animal hosts

-Eggs hatch in duodenum and spread to liver, lung, brain .., and produces large a fluid –filled cyst.

-cyst tend to be solitary, uniocular,white.

-Viable cysts are filled with a colorless fluid that contains daughter cysts and brood capsules with scolices.

Hydaid cyst gross


Three layers in cyst wall:

-Germinal Layer often with daughter cyst.

-Laminated membrane beneath germinal layer ,avascular eosinophilic refractile and chitinous.

-Outer layer is Dense Fibrovascular tissue with chronic inflammatory cells.

Hydatid cyst

The cyst wall is made up of a laminated membrane which is lined by germinal epithelium

Hydatid cyst

Hydatid cyst

The cyst wall consists of a laminated membranous structure which is lined by germinal epithelium .A calcified scolex and debris seen

Hydatid cyst

The germinal epithelium lining the hydatid membrane produces daughter cysts cantainingmultiple scoleces, it is called a brood capsule

Tuberculosis (TB)

-Due to Mycobacteria tuberculosis.

-Transmissions is from person to person via airborn droplets.

Infection doesn’t mean disease; most infected individuals are asymptomatic.

-M.Tuberculosis primarily infects macrophages.

Lung involvement is the major cause of morbidity/ mortality.

Gross description

*Inflamed, fibrotic ,nonfunctioning lung parenchyma.

*May have bronchiectasis cavitation and thickened pleura.

Tuberculosis

Multiple caseatinggranulomas


Inflammation produced with TB is Granulomatous, with epitheloidmacrophages and Langhans giant cells along with lymphocytes, plasma cells,few PMNs, fibroblasts with collagen and characteristic caseousnecrosis in the center.

Tuberculosis

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respiratory system pathology final

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