Differential Diagnosis for Peribronchovascular Consolidations with Surrounding GGO in an 87-Year-Old Female Under Immunotherapy for Cancer
Single Most Likely Diagnosis
- Immune-related pneumonia: Given the patient's history of immunotherapy for cancer, immune-related pneumonia is a well-documented side effect of such treatments. The changing location of consolidations on CT scans over a short period (2 months) supports this diagnosis, as immune-related adverse events can be dynamic and responsive to changes in treatment or the body's immune response.
Other Likely Diagnoses
- Infection (bacterial, viral, or fungal): In an immunocompromised patient, infections are a common cause of pulmonary consolidations. The fact that the location of the consolidations has changed could indicate a response to treatment or the progression of an infection.
- Progressive cancer or metastasis: Although the patient is under treatment, cancer can progress, and new pulmonary lesions could represent metastatic disease, especially if the primary cancer has a propensity to spread to the lungs.
- Radiation pneumonitis: If the patient has received radiation therapy as part of her cancer treatment, radiation pneumonitis is a possible cause, especially if the consolidations are in the radiation field.
Do Not Miss Diagnoses
- Pulmonary embolism: Although less likely given the description of peribronchovascular consolidations with GGO, pulmonary embolism can present with a variety of imaging findings and is critical not to miss due to its high mortality rate if untreated.
- Sepsis or severe infection leading to acute respiratory distress syndrome (ARDS): In an elderly, immunocompromised patient, any infection can quickly escalate to a life-threatening condition like sepsis or ARDS, which would require immediate intervention.
Rare Diagnoses
- Eosinophilic pneumonia: This is a rare condition that could present with consolidations and GGO on imaging, especially in the context of a changing clinical scenario or exposure to new medications, including immunotherapy.
- Hypersensitivity pneumonitis: Although more commonly associated with exposure to specific antigens (e.g., bird fancier's lung), in a patient undergoing immunotherapy, the immune system's dysregulation could potentially lead to an atypical presentation of hypersensitivity pneumonitis.
References:
- Naidoo J, Page DB, Li BT, et al. Toxicities of the anti-PD-1 and anti-PD-L1 immune checkpoint antibodies. Ann Oncol. 2015;26(12):2375-2391.
- Tirumani SH, Ramaiya NH, Keraliya AR, et al. Radiologic Profiling of Immune-Related Adverse Events in Advanced Melanoma Patients Treated with Ipilimumab. J Immunother. 2015;38(10):449-457.
- Toner GC, Panek RL, Walters IB. Radiation Pneumonitis. Clin Chest Med. 2017;38(2):233-241.