Extraabdominal lymph node metastasis in gastrointestinal stromal tumors (GIST)

The two principal ways of metastases in gastrointestinal stromal tumors (GISTs) are diffuse intraabdominal spread and liver metastasis whereas lymph node metastases (LNM) are extremely rare. Accordingly, nodal dissection is generally not recommended for GISTs' surgical treatment.

We present two unique cases of GIST with synchronous and metachronous extraabdominal LNM, whose clinical, macro-/microscopic, and immunohistochemical criteria, surgical and neo- or adjuvant therapy were investigated in retrospective analysis.

A 76-year-old man was presented with an inguinal mass and a simultaneously detected intraabdominal mass. Pathological evaluation of the core needle biopsy from the inguinal lymph node confirmed metastatic GIST. Partial resection of the ileum and inguinal lymph node dissection (LND) showed a spindle cell GIST in the ileum with inguinal LNM. Imatinib mesylate therapy was administered, which was interrupted 2 years later because of patient's intolerance. A 35-year-old man underwent extended gastrectomy, atypical liver resection, splenectomy, and LND because of a huge gastric fundus GIST. Postoperative imatinib mesylate therapy was administered. Histology showed multiple regional lymph node metastasis. Two years later, a left hemihepatectomy was performed for liver metastases. During follow-up, new axillary LNM were detected, and a sunitinib therapy was initiated. Thereafter, he developed progressive axillary, mediastinal, hepatic, abdominal, osseous, and cutaneous metastases, and he was treated by palliative cytoreductive surgery.

These two cases demonstrate that extraabdominal node metastasis may rarely occur in GIST, either initially or in the setting of widespread disease. In selected cases with confirmed or suspected LNM, LND should be considered. Metachronous extraabdominal lymph node metastasis represents a late event in high-risk GISTs and cannot be controlled by drug therapy alone.