Teaching Case

62- years old female patient, has contact to animals in daily life, presented with progredient dyspnoea and cough with accompanying clear mucus for several weeks. She has no history of fever, pain or loss of weight. Smoking and C2-abusus were denied. The patient was initially treated with antibiotics due to suspected alveolitis but showed no signs of recovery.   

The chest x-ray (Fig. 1) shows a homogenous and compact opacity in the middle and right lower lobe. The computed tomography (Fig. 2) shows consolidations and extended ground-glass-opacity as well as interlobular septal thickening – the so called „crazy paving pattern“ -  in all lobes of the right lung and parts of the left lung. There are no signs of necrosis or infiltration. FDG-PET-CT (Fig. 3) with strong FDG-Uptake in the lower right lobe (SUV max 6,3), but no distant metastatic disease. The chest x-ray six weeks later (Fig. 4) and one month before transplantation shows a progredient opacity in the right lung and new opacities in the left lung.

The patient initially presented with cough and progredient dyspnoea. As the patient has contact to animals in daily life and the first Chest X-ray showed a homogeneous opacity of the right lower and middle lobe, alveolitis was considered as the most likely diagnosis.  However, the antibiotic therapy was not successful. The symptoms of the patient even worsened in a month.

CT scan showed a diffuse, bilateral crazy paving pattern which is a nonspecific sign and can be seen in several diseases. Therefore, it was inevitable to perform a bronchial lavage with biopsy to determine the final diagnosis.

As final diagnosis, the pathology found an adenocarcinoma in situ with a lepidic growth pattern: this G1 NSCLC does not show any invasive growth pattern. Tumour cells spread along the alveolar septa without infiltration or destruction [1]. Complications are severe hypoxia and diffusion restriction. Nevertheless, if complete resection of the tumour is achievable, the prognosis is considerably good [2]. Our case had an unusual, diffuse and bilateral tumour spread, so resection was impossible. The only chance for full recovery was lung transplantation [3]. According to staging, there was no evidence of extrapulmonary or nodal disease, so our patient was listed for transplantation, which was subsequently performed without any complications. Now, it is crucial to establish the best follow-up strategy to prevent recurrence of the tumour.

In conclusion: Adenocarcinoma in situ is a rare, but important differential diagnosis for the crazy paving pattern.