Despite being the most common abdominal emergency in early childhood, intussusception is a rarely encountered pathology among adults. Starting from a mass or a lead point in the intestinal lumen, it is formed by telescopic invagination of the proximal loop into the distal loop. While intussusception in childhood is frequently idiopathic, in adults it commonly develops as a result of an underlying benign or malign etiology [2
]. In the case series described by Chiang and Lin, adenocarcinoma was involved in the majority of colon-based cases, while cases of intussusceptions located in the small intestines generally revealed more benign etiologies [3
]. In the presentation by Shi et al., 38 cases were reported as developing SBI due to metastatic disease between 1965 and 2007 [4
]. Since 2007, a Medline search found 22 more cases that have been reported. The distribution of these cases is shown in . Despite 15 of these cases being reported as being associated with lung cancer metastasis, only one of these cases was related to sarcomatoid carcinoma of the lung. This presentation provides a discussion of the second case in the literature.
Reported cases of adult small bowel intussusception caused by metastatic disease.
Lung cancer is the leading cause of cancer-related death worldwide. Lung carcinoma is capable of metastasis to other regions within the body. Patients are rarely symptomatic and can be diagnosed only following the development of complications such as obstruction, perforation, or hemorrhage. The proper evaluation of abdominal pathologies during follow-up of lung cancer is thus important. Despite Garwood et al. reporting on a series of 98 patients with lung cancer, with findings of gastrointestinal metastasis for adenocarcinoma (23.7%), squamous cell carcinoma (22.7%), large cell carcinoma (20.6%), and small cell carcinoma (19.6%), cases of intussusception associated with sarcomatoid carcinoma were very rare [5
]. This pathological subtype has more aggressive clinical picture compared to other non-small cell cancers [6
]. In a previously reported case (pT2, pN0), intussusception developed 17 months following the diagnosis of lung cancer, and the patient died on the 21st postoperative month. In the presented case, in which the disease was at a more advanced stage, symptoms were observed earlier and the survival period was correspondingly shorter.
Although it is known that lung carcinoma can metastasize to the small intestine via the hematogenous or lymphogenous paths, the exact route followed during metastasis is not known. However, retrograde metastasis to the lymphatic system of the small intestines via the thoracic duct appears possible. Immunohistochemical staining during histopathological evaluation is important for proper identification. In a review regarding sarcomatoid of the small bowel, strong positive results were observed with vimentin, cytokeratin AE1/AE3, and CK7, while negative staining was observed for the S100 protein, muscle cell actin, desmin, carsinoembryonic antigen, CK20, and CK117, which are important in differential diagnosis from other malignant pathologies [7
]. Similar results were obtained in the immunohistochemical evaluation of the presented case.
The treatment plan for adult intussusception consists of segmental resection and primary restoration of continuity of the gastrointestinal tract. As malignant pathologies are frequently observed in cases of colonic intussusception, reduction is not recommended for these cases [8
]. However, in cases of SBI it has been reported that resection can be performed following manual reduction to allow the resection of a smaller segment and to avoid the occurrence of short bowel syndrome. In SBI cases related to metastatic tumors there is always a risk of tumor perforation and complications that may arise due to ischemia in the intestinal mucosa. Therefore, resection without reduction will be more suitable in these cases. Due to the tendency of metastases to occur at multiple sites, the evaluation of all intestinal segments by palpation and, if possible, intraoperative enteroscopy can be considered.
In conclusion, it is important to consider that intestinal metastases of lung cancers can occur regardless of the type of pathology, that these metastases may have different clinical manifestations, and that the diagnostic and therapeutic approaches should be planned accordingly. Therefore, the existence of lung malignancies in the history of any patient presenting with abdominal symptoms should be evaluated carefully.