SOLITARY PULMONARY NODULES

Epidemiology: 1-2% of CXRs. 2-7% of these will be malignant

3 CLINICAL FEATURES WHICH INCREASE LIKELIHOOD OF BEING BENIGN:

1. No growth X 2 y

2. Ca++ in characteristic pattern

3. Age < 35 y

IF non-calcified and < 35 y, < 1% malignant

IF male, non-calcified, > 50 y, 50% malignant

Evalutation:

CXR

Calcification

1. bull’s-eye- granuloma

2. popcorn- hamartoma

3. eccentric- malignancy

Other characteristics

1. corona radiatia- 88-94% malignant

2. IN GENERAL well defined margins( benign, irregular margins( malignant

3. size- IF > 3 cm, only 5% benign

4. satellite lesions- usually benign

NOT helpful: cavitation, lobulation

CT

1. density- IF > 185 HU, likely benign

2. fat- benign, usually hamartoma

Bx

1. Flex bronch: 10-28% yield for malignancy with nodules < 2 cm, 40-68% for > 2 cm

2. PFNAB: 64-97% sensitivity for malignancy

MULTIPLE PULMONARY NODULES

MOST COMMON CAUSE: metastatic disease (occurs more often than all other causes combined). Mets tend to vary in size, cavitate, located peripherally in both lungs, at bases.

OTHER CAUSES

Benign: Histo, Coccidio, septic emboli, Nocardia, Crypto, paragonomiasis, hydatid cyst, Wegner’s, RA, AVM

Malignant: primary pulmonary lymphoma

Clinics in Chest Medicine, 13:1, 3/92, 83-95