Epidemiology
- Most common HIV-associated malignancy
- Decreasing incidence since start of AIDS era (declined from 60% of all AIDS cases in 1981 to 20% of all cases in 1987)
- Higher incidence in male homosexual cases than in IVDA or heterosexual partner cases
Physiology
- HIV-linked angiomatous proliferation (HIV may act as a cofactor or may produce a gene product that induces replication of angiomatous cells)
Diagnosis
- Pleural fluid: exudate
-Appearance: serosanguineous or hemorrhagic
-pH:
-LDH ratio:
-Total protein ratio:
-Glucose:
-Cell count/diff: cyto is usually negative
-Cholesterol: elevated >55-60 mg/dL (seen in all exudates)
-Pleural: serum cholesterol ratio: elevated (seen in all exudates)
Pleural Bx: usually negative (due to patchy nature of KS lesions)
Pleural fluid: transudate or exudate
-Appearance: serosanguinous or bloody
-CD34-positive cells: detected
Pleural Bx: usually not diagnostic (since KS typically involves visceral pleura >> parietal pleura)
FOB: red or violacious (flat or slightly raised) EB lesions may be seen
-Absence in visible airways does not rule out KS in more distal airways
-EBB/ TBB: usually not diagnostic/ may be hazardous due to risk of bleeding
-TBNA: may be useful for mediastinal nodes
OLB: fails to diagnose KS lesions in some cases
- CXR/Chest CT Pattern:
- Lung nodules: usually of various size and location
- Linear densities (following septal lines):
- Pleural effusion: may be bilateral/ variable size
- Usually accompanies parenchymal disease
- Hilar/ mediastinal adenopathy:
- Segmental/ lobar infiltrates: lees common
Clinical Presentations
- Pleural Effusion (see [[Pleural Effusion-Exudate]]): 30% of cases have pleural effusion
- Chylothorax (see [[Pleural Effusion-Chylothorax]])
Multisystem disease:
-Lung (lung involvement occurs after mucocutaneous involvement in 90-95% of cases/ lung involvement at autopsy, around 50%, is higher than that detected clinically, around 33% of cases/ 66% of patienst with known pulmonary KS with new CXR findings actually have an opportunistic infection rather than new KS lesions):
1) Progressive dyspnea:
2) Dry cough:
3) Hemoptysis/ chest pain: usually signal precipitous decline
4) Fever: less common (usually signals presence of coexisting infection)
5) Normal exam: may have crackles, etc. though
Treatment
Asymptomatic
- May follow patient closely
Symptomatic
- IFN-alpha + AZT: for cases with fairly preserved immune function
- Chemo (Adria/ Vincrist/ Bleo): for CD4 <200 or with history of opportunistic infections/ may control rate and growth of spread
- Visceral disease response usually parallels cutaneous disease response
- Response is usually temporary (lasts only a few months)
- XRT: obstructive lesions transiently respond
- Pleurodesis: for recur-rent effusions (not always successful though in KS)
References
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