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Solitary Lung Nodule

      A man with thyroid cancer had a lesion identified in the left lower lobe of the lung on computed tomography. The gross photograph of the bisected wedge resection specimen shows a relatively well-circumscribed glistening mass (arrow) in the lung parenchyma.
      • What is the best diagnosis for the lesion?
        • a.
          Pulmonary adenocarcinoma
        • b.
          Pulmonary hamartoma
        • c.
          Metastasis to the lung
        • d.
          Granuloma arising in the lung
      Answer: b. Pulmonary hamartoma.
      Pulmonary hamartoma is often incidentally discovered radiographically as a single well-circumscribed nodule with smooth margins and occasional calcifications, the so-called popcorn appearance (arrow, image A).
      • Gjevre J.A.
      • Myers J.L.
      • Prakash U.B.S.
      Pulmonary hamartomas.
      • Ost D.E.
      • Gould M.K.
      Decision making in patients with pulmonary nodules.
      On histopathologic examination, mature cartilage is identified in fibromyxoid stroma with interwoven adipose tissue (image B, arrow marks adipose). Various tissues have been identified in pulmonary hamartomas, including smooth muscle, fat, and bone.
      • Gjevre J.A.
      • Myers J.L.
      • Prakash U.B.S.
      Pulmonary hamartomas.
      • Ost D.E.
      • Gould M.K.
      Decision making in patients with pulmonary nodules.

      References

        • Gjevre J.A.
        • Myers J.L.
        • Prakash U.B.S.
        Pulmonary hamartomas.
        Mayo Clin Proc. 1996; 71: 14-20
        • Ost D.E.
        • Gould M.K.
        Decision making in patients with pulmonary nodules.
        Am J Respir Crit Care Med. 2012; 185: 363-372