Natasha Gupta1, Arpita
Chattopadhyay2, Rutuja Kishor
Nyayadhish3, Diganta Saikia4
Corresponding author: Dr. Arpita Chattopadhyay, Assistant Professor
(Pediatrics), Chacha Nehru Bal
Chikitsalaya, Geeta Colony, New Delhi. Chattopadhyay.arpita@gmail.com
1 Specialist (Radiology),2 Assistant
Professor (Pediatrics),3 Postgraduate Trainee
(Pediatrics),4 Professor (Pediatrics)
Affiliation: Chacha Nehru Bal Chikitsalaya, Geeta Colony, New Delhi.
To the Editor,
Necrotising pneumonia complicated by mycotic pseudoaneurysm has been
reported very rarely in infancy. Here we present a five month old girl
who had an acute life-threatening presentation of cavitatory pneumonia.
A five month old girl presented with painful swelling and induration
over right lower limb, below the knee joint, associated with high grade
fever for 15 days. For this complaint she was taken to a local
practitioner where she was advised incision and drainage of underlying
collection along with a course of intravenous antibiotics. However,
although the limb swelling subsided, high grade fever persisted. She
progressively developed rapid breathing over 5 days and presented to our
tertiary care centre in respiratory failure.
Examination revealed a sick child with respiratory rate – 74/min, HR-
186/min, saturation 81% on room air along with severe suprasternal and
subcostal retractions, diminished breath sounds over right hemithorax.
Laboratory indices suggested neutrophilic leukocytosis with high
C-reactive Protein. A Chest X Ray was obtained (Fig 1A), which showed
multiple large sized thin walled, cystic lesions in entire right lung
field and left lower zone in retrocardiac region, suggestive of
pneumatoceles, with the largest lesion in the right lower lung showing
an eccentric rounded mass within the cavity, projecting inside from its
medial wall (Figure 1).
Due to impending respiratory failure, child was emergently intubated
after shifting to the PICU and put on mechanical ventilation. After 2
hours of mechanical ventilation child suddenly began to desaturate
despite titration in settings. A repeat x-ray revealed a large area of
relative lucency with absent bronchovascular markings in the right
hemithorax, suggesting a pneumothorax. An emergent rightside intercostal
drain was inserted. The drain emptied 100 ml of purulent fluid in the
next three days. Subsequently over the course of five days, the child
was gradually weaned off mechanical ventilation and shifted to
humidified high flow nasal cannula. Blood culture came positive for
Methicillin Resistant Staphylococcus aureus sensitive to Vancomycin and
Linezolid.
As tachypnea persisted, a contrast enhanced CT scan of the Chest was
done, which showed multiple thin walled, rounded to irregular, air
filled cavities seen in right upper, right middle and left lower lobes,
the larger lesion in right middle lobe measuring 5.3 X2.8 X3.2 cm,
causing indentation of right heart border. Another large cavitatory
lesion was seen in the right lower lobe, with evidence of mild
consolidatory changes in the surrounding lung parenchyma. An intensely
enhancing lobulated rounded to ovoid lesion measuring 2.1 X1.5 X2.0 cm
was noted along the medial wall of this cavity, projecting into its
lumen, which showed enhancement, analogous to vascular enhancement in
the mediastinum. This lesion was seen to directly communicate with a
branch from descending branch of right pulmonary artery. A subcentimeter
well defined nodular lesion was seen in the parenchyma of left upper
lobe posteriorly, with a small peripheral subsegmental branch of
pulmonary artery seen to enter the nodule (Positive feeding vessel
sign), s/o Septic embolus in the lung, in view of the already diagnosed
Staphylococcal sepsis. A small fluid collection was also seen in right
pleural cavity, with thickened enhancing pleura, s/o small empyema, with
residual foci of air in pleural cavity from the previous intervention
(Fig 2 & 3).
Findings were suggestive of multiple pneumatoceles in both lungs, septic
embolus in left upper lobe and pulmonary artery pseudoaneurysm arising
from the descending branch of right pulmonary artery.
All the above findings can be explained as sequelae to Methicillin
Resistant Staphylococcal sepsis in the infant. Pneumatoceles may have
developed due to disseminated bacterimic seeding, while repeated septic
emboli to pulmonary arterial tree may have caused destruction and
weakening of the wall of vessel, resulting in a saccular outpouching
from the vessel wall, forming a pseudoaneurysm1.
Though rare, acquired pulmonary artery aneurysms have been reported in
adults with necrotising MRSA pneumonia, however, there is only one
report in 7 month old infant who underwent successful embolization of
peripheral pulmonary artery aneurysm2.Mycotic
aneurysms are mostly reported in patients with infective endocarditis,
intravenous drug abuse, traumatic injury and sepsis due to
Staphylococcus, Streptococcus or Mucormycosis.
In view of the potentially life-threatening nature of this condition, in
the probable event of rupture of the pseudoaneurysm, the baby was
referred to a higher centre for interventional management. He developed
one episode of hemoptysis during his stay and was subsequently planned
for high risk coil embolization which maybe a challenge considering the
small age of the patient, or lobectomy if it fails.
LEGENDS