FIGURE 9.

Lesions that represent potential mimickers of cyst-related primary lung malignancies. a) Irregular thick-walled cystic airspace in a 74-year-old male as an incidental finding on aortic imaging. Transthoracic biopsy showed chronic inflammatory changes without active components, and no signs of malignancy. The patient died 2 months later of an acute aortic rupture. b) One of several thick-walled cystic airspaces in a 62-year-old male with immunosuppression after kidney transplantation. Work-up showed invasive fungal infection, most likely mucormycosis. c) Thin-walled cystic airspace with an endophytic solid nodule, representing a rheumatoid nodule in a 60-year-old female with rheumatoid arthritis and several lung nodules. d) Several thin-walled cysts with ground-glass halo in a 73-year-old male with recurrent pneumothoraxes, first misinterpreted as infectious. After clinical deterioration and progression in size and number of cystic lung lesions pathology was obtained by wedge resection. It showed pure cystic metastases of a prior angiosarcoma of the scalp. The patient died shortly afterwards. e) Multiple thin-walled cysts with endo- and exophytic nodules in a 68-year-old female with Morbus–Sjögren and lymphoid interstitial pneumonia. Pathology showed that the solid components were amyloid depositions. f) Thick-walled cystic lesion in a 63-year-old female with allergic bronchopulmonary aspergillosis and aspergilloma. g) Multiple cavitating pulmonary nodules with a thick irregular wall in a 56-year-old female with vasculitis (granulomatosis with polyangiitis). h) Small subpleural thick-walled cyst in the left lower lobe of a 74-year-old male with a synchronous T1cN0M0 squamous cell carcinoma in the left upper lobe. Wedge resection was performed in addition to left upper lobe lobectomy, which showed chronic inflammatory changes without signs of a (second primary) malignancy.