hello again and welcome to another episode of cases in radiology. i'm Frank Gaillard the editor of Radiopaedia. org and today we're going to be looking at at a CT of the abdomen in a seventy-year-old female who presented with epigastric pain.
Her only relevant medical history was that of a past cholecystectomy. as always now is a perfect time to pause this video and take a minute or two to have a look at the case at your own pace. just follow the link which is either visible on your screen or included in the video description.
so here we have coronal and axial stacks through the abdomen. two main findings should have been evident. The first is that there is a small bowel obstruction as envisaged by these enlarged loops of dilated bowel.
these can be traced down into the lower abdomen to this point where there is an abrupt transition from the distended proximal lumen to the collapsed more distal lumen which has intussuscepted into the distal loop of bowel. this is also seen on axial imaging at this point where there is almost the characteristic donut appearance with mesenteric fat having been pulled into the lumen of the bowel. going back to the coronal imaging there is the impression off a lead point mass.
the other notable findings are bilateral very large renal masses, larger on the right. these appear centrally necrotic or cystic. there are numerous lymph nodes scattered throughout the mesentery which appear enlarged.
but no other solid masses are identified. incidental findings include a large simple renal cyst on the right. the first question you should ask yourself is whether or not the bilateral adrenal masses and the small bowel intussusception are related.
let's first talk about intussusception. intussusception is when one part of the bowel gets sucked into the more distal bowel and is further advanced by the action of peristalsis. in children this is most often idiopathic without an underlying cause identified, or certainly not an underlying pathological cause; its most often attributed to prominent lymphoid tissue in the submucosa.
in adults however a lead point is usually identified and in most instances it is that of a malignancy. in the large bowel it is that of a colorectal carcinoma which is by far the most common, however small bowel lymphoma and metastases to both large or small bowel particularly from malignant melanoma, breast cancer or lung cancer are identified. a number of benign neoplasms are also encountered.
as are some congenital abnormalities although these would be unlikely to first present in a seventy-year-old. inflammatory and trauma has also been reported but is unlikely. let's turn our attention to the adrenal glands.
by far the most common cause of bilateral adrenal masses is that of metastases; and the primary tumors to consider are those of lung cancer, breast cancer renal cancer which is not evident in this case, gastrointestinal malignancies, malignant melanoma and lymphoma. it is also worth considering primary tumours although most often these are unilateral. Pheochromocytomas for example are encountered bilaterally in up to ten percent of patients - whether this represents metastatic disease to the contralateral adrenal gland or synchronous tumours is debatable.
going back to this case we are left with four options. the first is that the small bowel mass and the bilateral adrenal masses are unrelated and that the adrenal masses were merely incidentally found due to the presentation of a small bowel obstruction. the second is that they are related and that both represent metastatic disease.
as we saw the primary lesions to be considered are breast cancer, lung cancer, and melanoma. the third and fourth possibilities are that one of these lesions represent the primary and that the other represent metastase. For example, the small bowel mass may be a primary adenocarcinoma or carcinoid of the small bowel with adrenal metastases.
Or potentially that we have bilateral adrenal malignancies with metastases to the small bowel. Review of a chest x-ray and inspection of the breasts remonstrated no obvious lung mass or breast mass. Further questioning of the patient did however reveal that seven years ago she had had a malignant melanoma excised from her back.
The patient went on to have a laparotomy and had the small bowel intussusception resected and the adrenal glands biopsied. malignant melanoma was the diagnosis in both instances. so this case is a good example of how systematically working through the differential diagnosis for separate lesions enables the underlying cause to be narrowed down.
malignant melanoma is particularly common in australia because all a population of immigrants who have fair skin from northern european countries now exposed to the harsh sun and the depleted ozone layer. it is a sinister tumour insofar that a lesion thought to completely have been excised many many years ago can present with metastatic disease and often can do so in unusual ways. it is one of the classic tumours to metastasise to small bowel and should be thought of high on the list when such presentations are encountered.
hope to see you again next time. Take care.
