Malignant gastrointestinal melanomas of unknown origin: Should it be considered primary?

Table 1 Patients’ data

Patient/Sex	A/m	B/f	C/f	D/m	E/f
Age (yr)	72	45	56	48	68
Location of melanoma	Small bowel	Small bowel	Small bowel	Anorectum	Anorectal juncture
Size of melanoma	12 cm × 6 cm × 6cm	Multiple tan-black lesions, ranging from 0.5 to 2 cm	4 cm × 5 cm	7.5 cm × 6 cm × 2.7cm	6 cm × 5 cm × 3 cm
Complains on admission	Intermittent right abdominal pain	Abdominal cramping, diarrhea, black stools since a month	Strangulated umbilical hernia	3-mo history of 2-3 kg weight loss, stools mixed with blood	Pruritus, tenesmus, bleeding during defecation
Physical examination	Palpable mass in the right lower quadrant	Acute abdomen	Strangulation	Digital rectal examina-tion: obstructive mass, just above the dentate line	Digital rectal examination: obstructive mass, blood
Preoperative work-up	CT scan: abdominal mass attached to the right colon	Plain X-rays: small bowel obstruction	No specific finding	Biopsy: ulcerated melanoma	Endoscopy: dark brown, partially ulcerated lesion
Operation	Exploratory laparotomy-segmental enterectomy	Laparotomy-segmental enterectomy	Hernioplastry-segmental enterectomy	Abdominoperineal resection	Sigmoidectomy-ileoanal anastomosis
Findings in operation	A mass found 30 cm distal to the Treitz ligament, causing partial obstruction	Intussusception, 40 cm in length-multiple tan-black lesions	Hernial sac: ileum with a 4 cm × 5 cm mass	Melanoma extended through the muscularis propria into the subserosa	Ulcerated melanotic lesion
Adjuvant therapies	Declined further treatment	No	No	No	No
Metastases	No infiltrated mesenteric lymph nodes	No	The whole thickness of the wall, 3/16 lymph nodes infiltrated	4/9 lymph nodes infiltrated	Extending to the serosa, 6/7 infiltrated local lymph nodes
Postoperative course	Uneventful	Uneventful	Uneventful	Uneventful	Uneventful
Follow-up	Died 1 yr	Disease-free 2 yr	Died 6 mo	Died 1 yr	Died 3 mo