Presentation
6 months of progressive shortness of breath. Now developing dysphagia and stridor on laying flat. Several palpable masses in the cervical region. No weight loss or fever. Otherwise fit and well, no previous imaging. No relevant family history.
Patient Data
There is a large mass involving the superior mediastinum and extending into the supraclavicular region.
There is significant displacement and narrowing of the trachea, and a minor thoracic scoliosis concave to the right.
The lungs are clear. Normal hila. No pleural effusion. Heart size is normal.
Extensive soft tissue mass within the middle and posterior portions of the superior mediastinum, extending into the neck.
The tissue is homogenous with minimal enhancement. No cavitation or calcification.
The trachea and left main bronchus are encased by the mass, with displacement and partially effacement.
There is also encasement of the major upper mediastinal vessels.
Abnormal soft tissue extends into the para vertebral region bilaterally, more extensive on the left, with a focal thoracic levoscoliosis.
The lungs are grossly clear. No pericardial or pleural effusion.
Further area of abnormal soft tissue encasing the suprarenal abdominal aorta, the celiac axis and the superior mesenteric artery. The appearances of this mass are similar to the mediastinal component.
Selected ultrasound images of the left anterior triangle and epigastric region.
Both of these show large well-defined, lobulated, heterogenous masses encasing the major vessels (e.g. left common carotid artery).
Case Discussion
The primary differential was initially felt to be lymphoma, although some of the features were not typical (vessels encased rather than displaced, minimal enhancement). There was a history of latent tuberculosis in the family, but this was felt to be an unlikely cause for this presentation. Neuroblastoma was also considered.
The degree of airway compression was critical on admission, and so the patient was started on steroids before biopsy. Further scans following this showed no change in the size of the mass, which meant the mass was unlikely to represent lymphoma.
The patient underwent an ultrasound guided biopsy of the cervical component. The histology was reported as: "Specimen comprises a lesion comprising spindled cells with spindled collagen strands with prominent myxoid stroma. There are occasional foci with nuclear pallisading reminiscent of Verocay bodies. There is no significant mitotic activity or atypia. Immunohistochemistry shows that there is fairly diffuse positivity for S100 and CD34. There is focal positive staining for CD56 and Factor XIIIa. Calretinin staining is negative. Ki67 shows a proliferation rate of <1%. While the presence of Verocay body-like areas is noted, the overall morphologic features and immunophenotype are most in keeping with plexiform neurofibroma. There is no evidence of atypia or malignancy."
On examination the patient was noted to have multiple cafe-au-lait spots. Together with the plexiform neurofibroma, this was sufficient for a diagnosis of neurofibromatosis type 1.