Nodular Patternitie

By

Gamal Rabie Agmy , MD , FCCP Professor of Chest Diseases ,Assiut University

Nodular Pattern

Nodular pattern A nodular pattern consists of multiple round opacities,

generally ranging in diameter from 1 mm to 1 cm

Nodular opacities may be described as miliary (1 to 2 mm,

the size of millet seeds), small, medium, or large, as the

diameter of the opacities increases

A nodular pattern, especially with predominant distribution,

suggests a specific differential diagnosis

Perilymphatic distribution

Centrilobular distribution

Random distribution

ARE NODULES IN CONTACT WITH PLEURA

NO

CENTRILOBULAR

YES

PERILYMPHATIC RANDOM

TO SUM UP..

• Random

– touch pleura

– scattered in lung

• Centrilobular

–away from pleura

• Perilymphatic

– around vessels, bronchi

– touch pleura or fissure

Size, Distribution, Appearance

Nodules and Nodular Opacities

Size

Small Nodules: <10 mm Miliary - <3 mm

Large Nodules: >10 mm Masses - >3 cms

Appearance

Interstitial opacity:

Well-defined, homogenous,

Soft-tissue density

Obscures the edges of vessels or adjacent structure

Air space:

Ill-defined, inhomogeneous.

Less dense than adjacent vessel – GGO

small nodule is difficult to identify

Interstitial

nodules Air space opacity

Miliary tuberculosis

sarcoidosis

in a lung transplant patient

with bronchopneumonia

RANDOM: no consistent relationship to any structures

PERILYMPHATIC: corresponds to distribution of lymphatics

CENTRILOBULAR: related to centrilobular structures Distribution

13

Angiocentric

Bronchocentric, ill Defined

Bronchocentric, well Defined

Lymphocentric

Disseminated histoplasmosis and nodular ILD.

CT scan shows multiple bilateral round circumscribed

pulmonary nodules.

Notice the nodules along the fissures indicating a

perilymphatic distribution (red arrows).

The majority of nodules located along the bronchovascular

bundle (yellow arrow).

Sarcoidosis

The majority of nodules located

along the bronchovascular bundle

(yellow arrow).

PERILYMPHATIC NODULES

Perilymphatic and Random distribution of

nodules , seen in sarcoidosis.

Centrilobular distribution

Hypersensitivity pneumonitis

Respiratory bronchiolitis in

smokers

infectious airways diseases

(endobronchial spread of

tuberculosis or

nontuberculous

mycobacteria,

bronchopneumonia)

Uncommon in

bronchioloalveolar

carcinoma, pulmonary

edema, vasculitis

Random distribution

Small random nodules

are seen in:

Hematogenous

metastases

Miliary tuberculosis

Miliary fungal infections

Sarcoidosis may mimick

this pattern, when very

extensive

Langerhans cell

histiocytosis (early

nodular stage)

Langerhans cell histiocytosis: early nodular stage before the typical cysts appear.

Differential diagnosis of a nodular

pattern of interstitial lung disease

SHRIMP Sarcoidosis

Histiocytosis (Langerhan cell

histiocytosis)

Hypersensitivity pneumonitis

Rheumatoid nodules

Infection (mycobacterial, fungal, viral)

Metastases, Miliary TB

Microlithiasis, alveolar

Pneumoconioses (silicosis, coal

worker's, berylliosis)

Reticulonodular pattern A reticulonodular pattern results from a

combination of reticular and nodular opacities.

This pattern is often difficult to distinguish from a purely reticular or nodular pattern, and in such a case a differential diagnosis should be developed based on the predominant pattern.

If there is no predominant pattern, causes of both nodular and reticular patterns should be considered.