Table 1 Contrasting pediatric and adult PLCH

Demographic features

Peak age at presentation

1-3 yrs [16]

20-40 yrs [5]

Smoking history

Infrequently described [16, 17]

Reported in > 95% [5, 12]

Imaging findings; chest CT

Distribution of abnormalities

Frequently involves lower lobes [18]

Sparing of bases and costo- phrenic angles is typical [19–21]

Biological character

Clonality

Invariably reported [22–24]

Suspect reactive rather than clonal [25]

Clinical Presentation

Single system vs multi-system presentation

Typically part of multi-system LCH [16]

Single system disease in > 80% of patients [5]

Management

Pharmacotherapy with prednisone/vinblastine

Complete or partial response frequently observed [26, 27]

Insufficient data available; likely limited response

Smoking cessation

Limited role as tobacco exposure not involved in most cases

Main and first line therapy in all adult smokers [28, 29]