A 43-year-old female patient is being followed up with a diagnosis of rheumatoid arthritis. She presented with ulcerated lesions on the lower extremity, diffuse subcutaneous nodules, dyspnea, hemoptysis, and fever. Cavitary lesions were detected on the chest X-ray and thoracic computed tomography (Figure 1). The biopsy sample taken from the lesion in the lung was interpreted as “tumor necrosis”. The biopsy sample from subcutaneous nodules was interpreted as ”T-cell/histiocyte-rich large B-cell lymphoma”.

Figure 1

There may be some similarities between various lung cavitary lesions, knowledge of the possible causes and a systematic approach will help to narrow down the huge list of differential diagnoses. CAVITY mnemonics can be used for diseases that may cause cavitary lesions in the lung (Table 1) (1). Pulmonary cysts are mimics of emphysema, cystic bronchiectasis, and bullous lung cavitary lesions, and before diagnosing a cavitary lesion, it should be ensured that it is not one of these mimics.

Table 1

Ethics

Informed Consent: Patient consent form was obtained.

Peer-review: Externally peer-reviewed.

Authorship Contributions

Surgical and Medical Practices: İ.G., Concept: İ.G., M.S.A., A.K., Design: A.K., Data Collection or Processing: M.S.A., Analysis or Interpretation: A.K., Literature Search: M.S.A., Writing: İ.G.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study received no financial support.