Presentation
Previous history of bilateral lung transplant.
Patient Data
There is a relatively well-defined RUL pulmonary nodule. The lungs and pleural spaces are otherwise clear. Right-sided port-a-cath in situ.
There is a 15 mm right upper lobe lobulated nodule, no other relevant lung abnormalities. Pleural spaces and airways are normal. No mediastinal lymphadenopathy.
The patient went for a wedge resection:
Macroscopy: Labeled "Right upper lobe wedge". Wedge weighing 6.5 g (post-inflation) measuring 60 x 18 mm. Pleura appears pale tan/grey. Centrally there is a pale tan/cream cavitating lesion measuring 16 x 13 x 11 mm. This is less than 1 mm from the green inked stapled resection margin and has opened to the pleural surface. Background parenchyma appears pale tan.
Microscopy: The sections show lung tissue with overlying visceral pleura. The parenchyma contains a cavitating lesion filled with fibrin and necrotic debris, with a periphery showing a histiocytic and granulomatous inflammatory reaction with localized fibrosis. Within the necrotic zone, there is frequent round yeast with distinct walls, surrounded by clear retraction spaces. The features are of a Cryptococcal abscess. Away from the lesion, the alveolar tissue has a normal architecture. There is no evidence of malignancy.
Conclusion: Right upper lobe lung, wedge excision: Features of an acute on chronic Cryptococcal abscess.
Case Discussion
This case shows an immunocompromised patient post bilateral lung transplant with no respiratory symptoms and presenting with a right upper lobe solitary pulmonary nodule. The new relatively well-defined lesion was highly concerning for a fungal infection. PTLD and other differentials were felt less-likely.