Clinical Profile:

AA 63 year old man presented at a nearby clinic with left sided chest pain since three months and cough since two weeks. He dis not complain of fever.

His Hb was 10g%), WBC count of 9700cells/cu mm, platelet count of 4 lakhs/cu mm and an ESR of 150

He was found to have systemic hypertension. On ECG and echocardiography atrial fibrillation and ejection fraction of 60% were diagnosed. He was prescribed warfarin for atrial fibrillation.

Radiological Investigations:

The frontal chest radiograph (Fig. 1) had shown a thick walled cavity with an air fluid level in the right lower zone. A diagnosis of a lung abscess was made and the patient was started on pain killers and intravenous antibiotics and discharged after 14 days

•10 days later, the patient noticed a swelling in the left anterior chest wall with worsening respiratory symptoms and was admitted at a local hospital and an emergency HRCT was performed. It showed a large thick walled cavity with air fluid level and a left sided soft tissue lesion extending from the pleural cavity to the subcutaneous plane with involvement of the costal cartilage of the third rib. This was diagnosed as a of lung abscess with cold abscess of the left anterior chest wall.

The patient was then started on antibiotics. The TB gene Xpert was negative for Tubercular bacilli. The WBC counts were normal .

Since the symptoms did not resolve, the patient was referred to our hospital for further evaluation.

•Frontal and lateral chest radiographs done at our institution show filling of the cavity. An air fluid level is not seen (*) and haziness in the left midzone corresponding to the soft tissue lesion in the lateral radiograph (Figs, 2a,b.c)

• The contrast enhanced CT scan showed the following:

• (a) and bone window(b) axial images shows a large peripherally enhancing heterogeneous density mass lesion with central necrotic component in the right middle lobe.

•A filling defect is seen in the right half of the left atrium and the pulmonary vein.

•A heterogeneously enhancing soft tissue lesion with multiple non enhancing areas within is seen in the left anterior chest wall suggesting neoplastic etiology . A PET scan and biopsy were advised.

Whole body PET/CT (Fig. 4) shows a heterogeneously enhancing, ill defined, spiculated, fissure based soft tissue mass involving the intermediate bronchus and the entire middle lobe of the right lung with a large 8.5x7.1x9.3cm sized cavity surrounded by peripheral FDG avid (SUV-26) uptake.

Infiltration into the left atrium and FDG avid left anterior chest wall mass and lymph nodes are seen (right upper paratracheal , right lower paratracheal , pre-vascular, epicardial , bilateral axillary, bilateral subpectoral , bilateral cervical level I and II).

Pathological findings:

The biopsy of the left anterior chest wall lesion shows tumor composed of nests of atypical squamous cells with pleomorphism, high N:C ratio , nuclear hyperchromasia. Many single cells are seen to invade the stroma (Fig. 5)

References :

1. Webb, textbook of thoracic imaging.

Acknowledgement:

We are grateful to the Department Of Pathology at our institution for providing the image of the histopathology with a description of the findings.