Editing Oesophageal cancer (section)

=== '''Rare     malignant tumours''' ===

** '''Small cell      carcinoma (0.6%)'''
*** Aggressive phenotype,       similar to other poorly-differentiated neuroendocrine cancers
*** Typically present with       lymph node involvement already
*** Overall prognosis poor but       long-term survival is possible with curative resections
** '''Primary      melanoma of the oesophagus (0.1%)'''
*** Generally late stage at       presentation, with poor prognosis
** '''Leiomyosarcoma'''
*** Far less common than       leiomyoma
*** Often erode through mucosa,       appearing as an ulcerated or exophytic mass
*** EUS - irregular borders and       more heterogenous than would be seen with leiomyoma
*** Oesophagectomy with radical       lymphadenectomy is treatment of choice, although prognosis is poor
** '''GIST'''
*** Similar appearance to       leiomyoma, differentiated by CD117 (c-kit) and CD34 stain positivity.       Also tend to be larger than leiomyomas, with uptake of IV contrast on CT       and significant PET avidity.
*** Can be enucleated provided       negative margins can be obtained; if not, formal oesophagectomy will be       required
*** Consider imatinib for any       GIST >3cm or with high-risk factors, or as neoadjuvant therapy for       locally advanced tumours
*** Lymph node metastasis is       unusual
*** Worse prognosis than       gastric GIST