Presentation
Left scapular pain and cough. As part of the GP's initial work up for the patients presentation, a chest x-ray was obtained.
Patient Data
CXR demonstrates a soft tissue mass arising in the superior sulcus of the left lung. It is not easy to see, but is associated with some loss of the normal fat planes in the supraclavicular soft tissues.
CT of the chest demonstrates a large posterior / superior left superior sulcus mass which invades into the chest wall and adjacent supraclavicular soft tissues. A number of enlarged lymph nodes are also present.
Patient is prone and a coaxial technique is used to biopsy the chest wall mass, approaching it medial to the scapula. Coaxial technique is useful as it allows multiple core samples to be obtained quickly once an appropriate position is obtained. In this case the risk on pneumothorax is minimal as no aerated lung is present.
Histology
MICROSCOPIC DESCRIPTION: The core biopsies show features of a poorly differentiated non-small cell carcinoma with areas of necrosis. The tumor forms sheets and cords, surrounded by inflamed stroma. The tumor cells have enlarged pleomorphic nuclei, prominent nucleoli and small amounts of ill-defined pale eosinophilic cytoplasm. There is no evidence of keratinization. No glandular structures are seen. No evidence of lymphovascular invasion is identified. The tumor cells are p63, CK5/6 and CK7 positive, indicating squamous differentiation. They are TTF-1, synaptophysin and melan-A negative.
DIAGNOSIS: Left superior sulcus: Poorly differentiated squamous cell carcinoma.
MR imaging targeted to the left brachial plexus performed including post gadolinium sequences. Correlation made with the CT examination. A 5.4 x 3.2 x 3.8 cm (trans x AP x CC) left apical peripherally enhancing soft tissue mass with invasion of the first and second ribs, involvement of the pedicle, transverse process, posterior elements and the posterolateral aspect of the T2 vertebral body and invasion of the posterior paravertebral musculature consistent with the history of Pancoast's tumor.
Abnormal marrow signal within the left lateral aspect of C7 and T1 vertebrae. No epidural soft tissue extension. The abnormal enhancing soft tissue extends through the intercostal musculature superiorly to the supraclavicular compartment with diffuse infiltration of the supraclavicular compartment in addition to supraclavicular lymphadenopathy. The cords and trunks of the left brachial plexus course through the abnormal enhancing soft tissue and are directly involved by the tumor. In addition the posterior divisions and cords demonstrate abnormal enhancement and thickening consistent with tumor infiltration. The abnormal soft tissue does not encased the subclavian vasculature.
CONCLUSION: Locally invasive left Pancoast tumor with destruction of the first and second ribs, invasion of supraclavicular fossa with direct involvement of the cords, trunks and posterior divisions of the left brachial plexus, C7, T1 and T2 vertebrae and paravertebral musculature.
Following 6 months of combined cis-platinum based chemo-radiotherapy the patient underwent further imaging to re-stage the tumor with a view to possible resection.
MRI with contrast, demonstrates reduction in left supraclavicular soft tissue enhancement. The left brachial plexus inferior trunk and divisions have also improved in appearance, with reduced enhancement and thickening. Direct tumor involvement of the left T1 and T2 nerve roots still appears present.
Case Discussion
This case demonstrates the full spectrum of imaging findings of a superior sulcus tumor (Pancoast tumor). After the initial core biopsy, the patient underwent 6 months of chemoradiotherapy in an attempt to downstage the tumor, as it was clearly involving the brachial plexus.
Although post-treatment (pre-resection) MRI continued to suggest involvement of the brachial plexus, a PET scan (not-shown) failed to show any uptake, and an en-block resection was performed, which fortunately also did not demonstrate any viable tumor. This patient is currently being followed up as an outpatient.
This is a good example of how difficult it is for non-functional imaging to distinguish viable from non-viable residual tumor.
En-bloc resection pathology
MACROSCOPIC DESCRIPTION: A lung wedge with attached chest wall including two ribs and muscles. The lung wedge, 100x35x45mm, contains a stapled surgical margin 130mm long.
Slicing shows a softened area next to the pleura measuring 25x15mm. No invasion is seen into the ribs. The lung parenchyma shows no discrete parenchymal lesions. Distance from margins: Medial soft tissue 3mm, lateral soft tissue 25mm, anterior soft tissue 15mm, posterior lung staple margin 30mm.
MICROSCOPIC DESCRIPTION: The biopsy contains nerve bundles, which are surrounded by fibrous tissue. No tumor is identified. The sections contain variable amounts of blood vessels, nerve fibers and fibrofatty connective tissue. They show no tumor involvement.
The sections contain lung parenchyma and attached chest wall. All the macroscopically abnormal tissue has been submitted. There is a large area of necrosis in the chest wall which is abutting the pleura. It contains focal mucin pools and dystrophic calcification. No viable tumor is identified. The adjacent lung shows no tumor. There is non-specific subpleural fibrosis. Lymphovascular or perineural invasion is not seen. The soft tissue and bony margins are unremarkable.
Sections of the completion lobectomy show no tumor. The bronchial resection margin is clear. There are four peribronchial lymph nodes with no tumor involvement. The lung parenchyma is unremarkable.
DIAGNOSIS:
- T1 nerve root, T2 pleura, inferior surface 1st rib, T1 root proximal, superior, inferior: No tumor identified.
- Chest wall: Large area of necrosis in the chest wall, consistent with pre-operative chemoradiation effect.
- Necrosis 25mm in size.
- No viable tumor identified (complete response).
- No evidence of lymphovascular invasion.
- All soft tissue and bony margins clear.
- Left upper lobectomy: No tumor identified.
- Bronchial margin unremarkable.
- 4 peribronchial lymph nodes present with no evidence of tumor.
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