Teaching Case

16-year-old female presents with a 2-week history of dry cough and polyarthralgia. Her past medical history included amygdalectomy in infancy and frequent epistaxis. A lower airway infection was presumed and medicated accordingly. One week later returns with fever, dyspnea, odynophagia and presented productive cough (with 1 episode of bloody streaks).

Chest radiograph (CR) on the first admission (Figure 1). CR 1 week after starting antibiotics showed worsening opacities on both lungs, with a suggestion of cavitation in the previously noticed lower left lung opacity (Figure 2). Further characterization by non-contrast chest computer tomography (CT) showed multiple pulmonary lung nodules, both centrally and peripherally and on upper and lower lobes, some of them with a ground glass halo and two of them with central cavitation (Figures 3, 4 and 5).

Background

There were two main imaging findings in the chest CT: (1) halo sign and (2) multiple cavities. The halo sign is non-specific and its differential diagnosis includes associated haemorrhage as well as local pulmonary infiltration by neoplasm.  [1]. A cavity refers to a gas-filled space in the centre of a consolidation or nodule [1].

Clinical perspective

Age, gender, history of epistaxis and polyarthralgias and the episode of bloody-streaked sputum and an elevated C reactive protein (CRP) with no leucocytosis suggests a vasculitis. Due to clinical and radiological worsening 1week after starting antibiotics a chest CT was requested, which provided more hints towards the diagnosis of vasculitis.

Imaging Perspective

Upon multiple pulmonary cavitating nodules, a radiological differential diagnosis includes the acronym “CAVIty” [2]:

1. Cancer – our patient presented with a subacute clinical picture, making metastatic cancer very unlikely. In the appropriate clinical setting, we could include in the differential diagnosis metastatic head and neck cancer or colon cancer. Regarding the age group, metastatic sarcoma and Hodgkin lymphoma could hypothetically be responsible for multiple pulmonary cavitating metastasis [3]. She had no lymphadenopathies.
2. Auto-immunity – Includes vasculitis, necrobiotic nodules (associated with inflammatory bowel disease or rheumatoid nodules) or sarcoidosis. Amongst small vessel vasculitis the differential diagnosis includes IgA vasculitis, eosinophilic granulomatosis and granulomatosis with polyangiitis. Anti-neutrophil cytoplasmic antibodies (ANCA) positivity aids in their differential diagnosis [4]. Regarding necrobiotic nodules, thoracic manifestations of IBD (which may be similar to granulomatosis with polyangiitis) may present before colonic disease [5]. Rheumatoid nodules are typically associated with long-standing active disease. Cavitating sarcoidosis is a rare presentation in patients with an aggressive active disease.
3. Vascular – Septic emboli could be hypothesized. She had no history of drug abuse. Hemocultures were negative, echocardiography unremarkable (for endocarditis). Doppler ultrasound excluded infected thrombus in systemic veins which could be responsible for the septic emboli (Lemierre’s syndrome). Septic emboli usually present with peripherally cavitating nodules with feeding vessel sign.
4. Infectious –The clinical picture was not suggestive. Pulmonary post-primary tuberculosis could present with cavitating nodules. Those usually are predominant in the posterior segments of the upper lobe and superior segments of the lower lobe and present other signs of endobronchial spread of infection. Necrotizing pneumonias or fungal infections (in an immunocompromised patient) could hypothetically be responsible.

Outcome: Patient was IgG class ANCA directed to proteinase 3 (ANCA PR3) positive, suggesting granulomatosis with polyangiitis [6]. Bronchofibroscopy revealed a tracheal hyperemic friable mucosa (no stenosis). Biopsy of the nasal septum mucosa, which presented whitish lesions, confirmed the diagnosis. These mucosal lesions are believed to be responsible for the past medical history of frequent epistaxis mentioned in the clinical history section above. Interestingly, regarding the other past medical history of amygdalectomy also mentioned in the same section, there is some literature suggesting these patients may have higher rates of amygdalitis [7] although we cannot prove that in our case there is any relationship between those.

Take Home Message / Teaching Points

Upon multiple pulmonary cavitating nodules, a radiological differential diagnosis includes the acronym “CAVIty”.

Persistent fever, elevated CRP, sinusitis and cavitating pulmonary infiltrates should suggest granulomatosis with polyangiitis.

Written informed patient consent for publication has been obtained.