Cappellari: Pleural Pathology

Front 1

Pleural effusion causes

Back 1

Increased hydrostatic pressure (CHF)
Decreased oncotic pressure (nephrotic syndrome)
Increased vascular permeability (pneumonia)
Increased intrapleural negative pressure (atelectasis)
Decreased lymphatic drainage (tumor)

Front 2

Inflammatory pleura

Back 2

Serofibrinous pleuritis
-Serofibrinous exudate
-e.g., secondary to pulmonary inflammation, collagen vascular diseases

Suppurative pleuritis (empyema)
-Pus
-e.g., secondary to pneumonia

Hemorrhagic pleuritis
-Bloody exudate
-e.g., secondary to tumor

Front 3

Noninflammatory pleura

Back 3

Hydrothorax
-Transudate
-e.g., secondary to CHF

Hemothorax
-Blood
-e.g., ruptured aortic aneurysm

Chylothorax
-Chyle (lymph)
-e.g., secondary to obstruction of lymphatics by tumor or thoracic duct trauma

Front 4

Pleural neoplasm: solitary fibrous tumor overview

Back 4

Rare
Malignant transformation rare
Usually incidental finding on CXR
NOT associated with asbestos
Usually arise from visceral pleura
-origin: mesothelial vs submesothelial fibroblasts
May be found at other sites

Front 5

Pleural neoplasm: solitary fibrous tumor appearance and histology

Back 5

Gross: white, rounded, firm, several centimeters

Histology:
- fibroblast-like cells well circumscribed in a background of collagen
- haphazard arrangement of cells (“patternless” pattern)
- CD34 positive

Front 6

Mesothelioma: definition and epidemiology

Back 6

Definition: A malignant tumor derived from the lining cells (that is, mesothelial cells) of a serous cavity (e.g. pleura, peritoneum, pericardium)

Uncommon
Most are asbestos related (estimate 70-90%)
-exposure histories
-increased numbers of asbestos bodies in lungs of patients with mesothelioma

Amphibole asbestos (long thin fibers) are more potent carcinogens

incidence of MM rises with intensity and duration of exposure to asbestos

long latency between asbestos exposure and development of mesothelioma (20-50 years; avg 35 years)

Front 7

Pleural plaque: histology

Back 7

Hypocellular tissue rich in collagen

Front 8

Mesothelioma: clinical features

Back 8

Most patients are 50-70 years of age
Males predominate (~75%)
Symptoms: include chest pain, dyspnea
Average survival for pleural mesothelioma from onset of symptoms=12-15 months and from time of diagnosis=8-12 months but longer survival times have been reported

Front 9

Mesothelioma: classification

Back 9

Epithelioid mesothelioma
Sarcomatoid mesothelioma
-desmoplastic mesothelioma
Biphasic mesothelioma

Front 10

Mesothelioma: gross pathology

Back 10

small nodules increase in size, eventually becoming confluent and encasing the lung
tumor may invade the chest wall/mediastinum
tumor often spreads to pericardium, contralateral pleura and peritoneum
may metastasize to mediastinal lymph nodes
distant metastases may be present but are not usually clinically evident

Front 11

Mesothelioma: epithelial type

Back 11

~50% of mesotheliomas
Usually tubulopapillary, but may be solid
Main differential diagnosis is metastatic adenocarcinoma
Diagnosis often requires histochemical stains, immunohistochemical stains and possibly electron microscopy
-Cytokeratin, Calretinin positive

Front 12

Mesothelioma: sarcomatoid type

Back 12

~15% of mesotheliomas
Malignant-appearing spindle or oval cells-can resemble a variety of sarcomas
In the desmoplastic variant, more than 50% of the tumor is fibrous and poorly cellular; it may be difficult to distinguish from reactive fibrosis

Front 13

Non-primary tumors involving the pleura

Back 13

Most tumors involving the pleura represent either metastases or direct extension to the pleura from a lung primary
Most common secondary tumors involving pleura: lung, breast
Less common: hematologic (lymphoma/leukemia), ovary, gastrointestinal