Ground-glass density nodule

A ground-glass density nodule (GGN) is a circumscribed area of increased pulmonary attenuation with preservation of the bronchial and vascular margins. A GGN can be:

• partly solid (part of the ground-glass opacity completely obscures the parenchyma)
• non-solid (no completely obscured areas) - pure ground-glass nodules

Although encountered regularly, the incidence of cancer in these nodules has been reported as high as 63% (for partly solid nodules, in one study). Histologically these may represent:

• malignancy
  • primary (e.g., bronchoalveolar carcinoma (BAC), adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma)
  • metastases: occasionally can manifest as ground glass density nodules ⁶
• atypical adenomatous hyperplasia
• focal interstitial fibrosis
• aspergillosis
• focal pulmonary hemorrhages

See also

• ground-glass
• diffuse ground-glass nodules
• pulmonary nodule