Clinicopathological analysis of small intestinal metastasis from extra-abdominal/extra-pelvic malignancy.

Background: The metastatic tumors in the small intestine secondary to extra-abdominal/extra-pelvic malignancy are extremely rare. However, the small intestine metastases are extremely prone to misdiagnosis and missed diagnosis due to the lack of specific clinical manifestations and examination methods, thus delaying its treatment. Therefore, in order to improve clinical diagnosis and treatment capabilities, it is necessary to summarize its clinical pathological characteristics and prognosis.

Aim: To summarize the clinicopathological characteristics of patients with small intestinal metastases from extra-abdominal/extra-pelvic malignancy, and to improve the clinical capability of diagnosis and treatment for rare metastatic tumors in the small intestine.

Methods: The clinical data of patients with small intestinal metastases from extra-abdominal/extra-pelvic malignancy were retrieved and summarized, who admitted to and treated in the Air Force Medical Center, Chinese People's Liberation Army. Then descriptive statistics were performed on the general conditions, primary tumors, secondary tumors in the small intestine, diagnosis and treatment processes, and prognosis.

Results: Totally 11 patients (9 males and 2 females) were enrolled in this study, including 8 cases (72.3%) of primary lung cancer, 1 case (9.1%) of malignant lymphoma of the thyroid, 1 case (9.1%) of cutaneous malignant melanoma, and 1 case (9.1%) of testicular cancer. The median age at the diagnosis of primary tumors was 57.9 years old, the median age at the diagnosis of metastatic tumors in the small intestine was 58.81 years old, and the average duration from initial diagnosis of primary tumors to definite diagnosis of small intestinal metastases was 9 months (0-36 months). Moreover, small intestinal metastases was identified at the diagnosis of primary tumors in 4 cases. The small intestinal metastases were distributed in the jejunum and ileum, with such clinical manifestations as hematochezia (5, 45.4%) and abdominal pain, vomiting and other obstruction (4, 36.4%). In addition, 2 patients had no obvious symptoms at the diagnosis of small intestinal metastases, and 5 patients underwent radical resection of small intestinal malignancies and recovered well after surgery. A total of 3 patients did not receive subsequent treatment due to advanced conditions.

Conclusion: Small intestinal metastases of extra-abdominal/extra-pelvic malignancy is rare with high malignancy and great difficulty in diagnosis and treatment. Clinically, patients with extra-abdominal/extra-pelvic malignancy should be alert to the occurrence of this disease, and their prognosis may be improved through active surgery combined with standard targeted therapy.