Carcinoid tumor of the ileum with metastasis to orbit

Case contributed by RMH Neuropathology


Orbital nodule stable in size for 18 months. Later was found to have the ileal tumor

Patient Data

Age: 65 years
Gender: Female

A well circumscribed right orbital mass demonstrating homogeneous contrast enhancement is seen. It displaces the medial rectus inferiorly and the superior rectus laterally. The optic nerve is displaced inferolaterally. 

Histology (orbit)



An irregular grey tan nodule, 20x10x10mm. Inked blue and serially sectioned.


Paraffin sections show a densely hypercellular tumor. This consists of cells with uniform round and oval vesicular nuclei with conspicuous nucleoli and a small amount of pale cytoplasm. These are arranged in irregularly shaped solid islands which are haphazardly dispersed in a dense fibrous stroma. A palisaded arrangement of tumor cells at the periphery of these islands is noted. Occasional mitoses are identified. No necrosis is seen. Immunohistochemistry shows strong staining in tumor cells for pancytokeratin AE1/AE3, BerEp4, synaptophysin, CDX2 and neuron specific enolase (NSE) and moderate staining for CD56. No staining for S-100 protein or TTF-1 is seen in tumor cells. The features are of carcinoid tumor. The topoisomerase labeling index is approximately 3%

FINAL DIAGNOSIS:Right orbital tumor: Carcinoid tumor

Primary carcinoid tumors of the orbit are rare. Those that have been reported have usually had a dural attachment. Metastatic carcinoid tumors usually have atypical features which this tumor lacks. Primary sites that should be excluded however include lung, cecum/appendix, small bowel and pancreas.

CT Abdo/Pelvis following histology


2 cm lesion is seen in the mid-distal ileum, 50 to 60 cm from the ileocecal valve. This is associated with a very short segment intussusception. Adjacent mesenteric masses, the largest measuring 2.2 x 1.2 x 2.0 cm, shows mild desmoplastic reaction.

No para-aortic, retroperitoneal and inguinal or thoracic lymphadenopathy. An enhancing lesion in hepatic segment 7 measures 1.9 x 1.5 x 1.3 cm. No further liver lesions are seen. Multiple small soft tissue nodules are seen from the gallbladder wall, likely polyps. No abnormality of the kidneys, spleen, pancreas, adrenals or bladder. No suspicious expansile or destructive osseous lesions.


Ileal lesion, with adjacent desmoplastic mesenteric mass is concerning for a carcinoid tumor. Local mesenteric lymphadenopathy.

Enhancing hepatic lesion may represent a carcinoid metastasis, with the differential being a hemangioma. This could be further evaluated with contrast enhanced ultrasound or quad-phase CT.

Histology (bowel)



The specimen is a 300mm length of small bowel 20mm in diameter. Attached is mesentery along its entire length up to 50mm in thickness and 30mm in width. A polypoid brown tan nodule 35x25x15mm arises within the small bowel lumen. The nodule appears to push into but not through muscularis propria. The small bowel serosa is not affected and the lesion is 122mm from the closest resection margin. Multiple nodes are present in the small bowel mesentry.


Sections show a neuroendocrine carcinoma extending into and focally through the muscularis propria. The tumor is composed of variably sized nests of mono-morphic polygonal cells with round nuclei and vesicular chromatin. There are up to 28 mitoses per 10 high power fields. There is no necrosis. Small nests are seen infiltrating through the muscularis propria and into adventitia with focal involvement of the serosal surface. Extensive lymphovascular invasion is identified. There is no perineural invasion. The mucosal margins are not involved by tumor. Metastatic tumor is present in 6 of 14 lymph nodes, including the apical lymph node. There are mutliple foci of extra-nodal extension. 


Well differentiated neuroendocrine carcinoma (AJCC pT4, pN2, M1 Stage IV 2).

This tumor has been compared with the previous orbital mass and has the same morphological appearance. The findings are consistent with a primary small bowel neuroendocrine carcinoma metastastic to the orbit.

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