Eggshell calcification (lymph nodes)

Eggshell calcification refers to fine calcification seen at the periphery of a mass and usually relates to lamellar lymph node calcification. For similar appearance in the breast see eggshell calcification (breast).

In 1967 Jacobsen and Felson published criteria to help "avoid over-reading of the incidental circumferential concentrations of calcium and to eliminate confusion with the ring shadows of bronchi on end." These criteria were :

• shell-like calcifications up to 2 mm thick must be present in the peripheral zone of at least two lymph nodes
• the calcifications may be solid or broken
• in at least one of the lymph nodes, the ringlike shadow must be complete
• the central part of the lymph node may show additional calcifications
• one of the affected lymph nodes must be at least 1 cm in its greatest diameter

Pathology

Etiology

In the mediastinum and thorax :

• silicosis: 5% patients
• treated lymphoma: (postirradiation Hodgkin disease) usually 1-9 years following treatment
• coal workers' pneumoconiosis (CWP): 1% patients
• sarcoidosis: calcification is uncommon (only 5% of patients) and occurs late in the disease; only rarely does it have an eggshell configuration
• scleroderma
• amyloidosis: rare
• blastomycosis (e.g. pulmonary blastomycosis): rare 
• histoplasmosis (e.g. pulmonary histoplasmosis): rare

Differential diagnosis

For eggshell like calcification appearances in the thorax consider:

• aneurysms
• parathyroid tumors
• pulmonary arteries in pulmonary arterial hypertension
• thymic cysts
• thyroid tumors and multinodular goiter

See also

• differential of calcified mediastinal lymph nodes

Siehe auch:

• verkalkte mediastinale Lymphknoten
• Sarkoidose
• Silikose
• pulmonale Hypertonie
• Eierschalenverkalkungen
• Thymuszyste
• Schilddrüsenknoten mit randständigen Verkalkungen (Eierschalen)
• thyroid tumours
• Eierschalenverkalkungen in der Mamma