Ileal "carcinoid" tumors-small size belies deadly intent: high rate of nodal metastasis in tumors ≤1 cm in size.
Neuroendocrine tumors (NETs) account for 2% of tumors of the gastrointestinal tract, most occurring in the small intestine. A size of 2 cm is generally regarded as a cut-off point for risk of lymph node metastasis in intestinal neuroendocrine tumors in the absence of other high-risk features; however, metastatic disease has been reported in 12% of tumors of the jejunum and ileum measuring 1 cm or less. Archives from 2 institutions were searched for ileal NETs measuring 1 cm or less, and selected data were recorded. Twenty-one ileal NETs were identified measuring ≤1 cm. Six (29%) were multifocal and 7 (33%) had distant metastasis at diagnosis. Regional lymph nodes were examined in 14 cases (67%), and 10 of these cases (71%) showed lymph node metastasis. Mean primary tumor size in cases with nodal metastasis was 7.3 mm. In this series of ileal NETs ≤1 cm in size, the rate of lymph node metastasis was 48% overall and 71% for cases with regional lymph node resections. In addition, 33% showed distant metastasis at the time of diagnosis. Tumors as small as 3 mm and those confined to the submucosa can give rise to nodal metastasis, emphasizing the need for consideration of local resection with regional lymphadenectomy, even for subcentimeter ileal NETs.
Department of Pathology and Laboratory Medicine, Western University and London Health Sciences Centre, London, ON, N6A 5A5, Canada. Electronic address: joanna.walsh@lhsc.on.ca.
Joanna C
JC
Walsh
Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, BC, V5Z 1M9, Canada.
David F
DF
Schaeffer
Pathology & Lab Medicine, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.
Richard
R
Kirsch
Pathology & Lab Medicine, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.
Aaron
A
Pollett
Department of Endocrinology and Internal Medicine, San Raffaele Scientific Institute, Ospedale San Raffaele - Milano, 20132 Milano, Italia.
Marco
M
Manzoni
Pathology & Lab Medicine, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.
Robert H
RH
Riddell
Pathology Unit, San Raffaele Scientific Institute, Ospedale San Raffaele - Milano, 20132 Milano, Italia.
Luca
L
Albarello
D000046:Academic Medical Centers; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002276:Carcinoid Tumor / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D005260:Female; D006801:Humans; D007078:Ileal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D007414:Intestinal Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery; D007558:Italy; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009864:Ontario; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden
Carcinoid; Ileum; Lymph node metastasis; Neuroendocrine tumor; Small intestine