Lung adenocarcinoma recurrence after stereotactic body radiotherapy

Case contributed by Dr Bruno Di Muzio

Presentation

Chest pain.

Patient Data

Age: 50 years
Gender: Female

Right upper zones rounded lung mass associated with likely prominent lymph nodes in the right paratracheal stripe and right hilum. 

Nuclear medicine

18F-FDG PET-CT

Intensively avid 5.5 cm right upper lobe mass associated with avid lymphadenopathy involving the right hilar, subcarinal, right paratracheal, and right supraclavicular chains. No distant metastatic disease. 

This patient had chemoradiotherapy and multiple imaging follow-ups. She was upstaged later due to pericardial metastatic deposits and lung nodules (not shown).

Post-radiation scar in the right upper lobe. 

Stable right middle lobe nodule abutting the pericardium. Stable lung nodules within the left upper and superior segment of the left lower lobe, the largest of which in the perihilar region of the left upper lobe, measuring 7mm. No new pulmonary nodules. The lungs and pleural spaces are otherwise clear.

Within the limits of this scan, normal appearance of the mediastinal soft tissue and vascular structures. No mediastinal, hilar, or axillary lymphadenopathy.

Stable post-radiation fibrosis and complete right upper lobe collapse. Within the region of fibrosis, round low attenuation nodule of 15 mm is identified.  Although this may represent necrotic tumor, it is slightly larger compared to previous scans with subtle convex bulging of the right lateral margin.  Locoregional tumor recurrence needs to be considered.

Annotated image

Recurrence at the radiation portal

Annotated images comparing current CT (right) to one year earlier (left). 

Nuclear medicine

18F-FDG PET-CT

Comparative PET images from the time of diagnosis, 2 years, and current recurrence.  

Macroscopy: Labelled "Right upper and middle lobe of lung". Perihilar soft tissue is present over a bare area on the medial aspect 55 x 46 mm (inked green).  Bronchial and vascular resection margins amputated, resulting surfaces inked blue.  Parenchymal staple lines amputated, resulting surfaces inked black. There is a moderately firm lobulated yellow lesion in the lobe, which abuts the does not appear to cross the fissure into the lobe.  The lesion has central areas of yellow necrosis. Peritumoral parenchymal changes seen with areas of grey mottling of the parenchyma distal to the tumour site within the lobe.  

Microscopy: The sections taken from the macroscopically described tumour show an invasive tumour, composed of irregular fused glands with cribriform formation, papillary structures and numerous nests of atypical epithelial cells. The tumour cells have moderate to abundant pale to eosinophilic cytoplasm, moderate nuclear pleomorphism, irregular nuclear membranes and prominent nucleoli. There is frequent atypical mitosis. Stromal retraction artefact is present. There are foci of necrosis, fibrosis with accompanying active chronic inflammation including foamy macrophages and multinucleated giant cells surrounding cholesterol clefts. Vascular wall changes and atypical stromal cells are seen. These features are in keeping with the treatment effect. There is extensive lymphovascular invasion, including within bronchovascular bundles of an adjacent lobe. No discrete tumour nodule is seen in adjacent lobe. No perineural invasion is seen. Residual tumour cells are seen within peritumoral changes described macroscopically. Estimated tumour size is 43 mm. The tumour is clear of resection margins. Four hilar lymph nodes show sclerosis with chronic inflammation including histiocytes, in keeping with treatment effect. One of the lymph nodes shows a small focus of intravascular adenocarcinoma, 0.05 mm in size.

Conclusion: Right upper and middle lobe of lung:

  • Histological type        Adenocarcinoma, acinar predominant
  • Tumour size             47 mm in maximal dimension
  • Visceral pleural invasion         Not identified
  • Lymphovascular invasion       Extensive, into the adjacent lobe
  • Perineural invasion        Not identified
  • Bronchial resection margin    Not involved
  • Vascular resection margin    Not involved
  • Response to neoadjuvant therapy >10% residual viable tumour
  • Hilar lymph nodes        Positive (1/4), treatment effect present

Case Discussion

This case illustrates an advanced lung adenocarcinoma, initially stage IIIC, further progressing to stage IV (images of this progression not shown). The main point here is to demonstrate how important it is to assess the lung radiation field/scar with attention, chasing for any new growth or bulging of the contours (see annotated images). 

The images of the last CT scan demonstrate right upper lobe in-field tumor recurrence. The patient was offered further resection, given her response to the disease elsewhere. 

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Case information

rID: 81506
Published: 26th Aug 2020
Last edited: 27th Aug 2020
System: Chest
Inclusion in quiz mode: Included