Alternative explanations that argue for the development of primary GI melanomas include the migration of neural crest cells through the omphalomesenteric canal (an explanation that is applicable to melanoma of the ileum only) (25), and the neoplastic transformation of APUD cells (amine precursor uptake and decarboxylation cells) in noncutaneous sites (26,27). Inhibitors,research,lifescience,medical The lack of clarity of GI melanoma pathogenesis has led to the development of criteria for diagnosing a primary GI malignant melanoma. These include: no concurrent or prior excision of melanoma

or atypical melanotic lesion from the skin, lack of involvement of other organs, lack of in situ Gefitinib solubility dmso change in overlying or adjacent GI epithelium, and 12 month disease-free survival after diagnosis (28). Management of primary gastric melanoma is primarily surgical. A review of nine cases of gastric Inhibitors,research,lifescience,medical melanoma in which no known extra-gastric primary was identified reveals that eight of the

nine cases were treated with surgery. Three of the cases were treated with partial gastrectomy and splenectomy (2,4,6), two cases were treated with partial gastrectomy alone (5,8), one with total gastrectomy (7), one with gastrectomy, pancreatectomy, splenectomy, and transverse colectomy (9), and one stated to be “palliative resection” Inhibitors,research,lifescience,medical (3). Only one case was treated with adjuvant therapy and that patient received 12 months of adjuvant interferon (4). The primary gastric melanoma case that was not treated surgically was treated with dacarbazine and cisplatin-based chemo due to peripancreatic and axillary nodal metastases (18). Those with no identifiable primary lesion had variable outcomes. In the case Inhibitors,research,lifescience,medical treated with partial gastrectomy and splenectomy followed by 12 months of adjuvant interferon, the patient showed Inhibitors,research,lifescience,medical no evidence of disease on EGD two years post-operative (4). Another case treated with partial gastrectomy and splenectomy showed

a similar outcome with the patient being disease free at 16 months post-op (6), and one case reported patient survival with no evidence of disease at five years post-total gastrectomy (7). Of the surgical cases with poorer outcomes, one patient with comorbid dermatomyositis died due to post-operative complications Metalloexopeptidase following a partial gastrectomy (5), one patient succumbed to metastases 12 months following a distal gastrectomy (8), and another patient died 11 months post-operative following a gastrectomy, pancreatectomy, splenectomy, and transverse colectomy for a locally invasive gastric melanoma (9). Two cases were lost to follow up (2,3). In contrast to the surgery-based management of gastric melanoma with no known primary, chemotherapy and radiation therapy play a larger role gastric melanoma with a known extra-gastric primary.