Radiosensitive orbital metastasis as presentation of occult colonic adenocarcinoma

Abstract

An 82-year-old man presented with progressive right frontal headaches. The patient's history was significant for benign polyps on surveillance colonoscopy 2 years prior, without high-grade dysplasia or carcinoma. MRI revealed an enhancing lesion arising within the superomedial aspect of the right orbit. Lesion biopsy demonstrated histological appearance and immunophenotype suggestive of colonic adenocarcinoma. Staging positron emission tomography/CT showed visceral metastases and diffuse activity in the posterior rectosigmoid, consistent with metastatic colon cancer. Treatment of the orbital lesion with external beam radiotherapy to 30 Gy resulted in significant palliation of the patient's headaches. The patient expired 2 months following treatment completion due to disease progression. Orbital metastasis as the initial presentation of an occult colorectal primary lesion is exceedingly rare, and occurred in this patient despite surveillance colonoscopy. Radiotherapy remains an efficacious modality for treatment of orbital metastases.

Analysis of radiation effects in two irradiated tumor spheroid models

“…From a clinical perspective, pancreatic neuroendocrine tumors are often considered slow growing and more radioresistant than other cancer types, including colonic adenocarcinoma. The radiosensitivity of HCT116 has been thoroughly investigated and represents as a fairly radiosensitive cell line, making the comparison to the more radioresistant BON1 cell line relevant ( 15 – 17 ). One potential explanation for the different radiosensitivities observed for the two spheroid models could be that the slow growing spheroids harbor a lower percentage of cells in radiosensitive cell cycle phases, such as the M-phase and G 2 -phase, at the time of irradiation, which could result in a greater therapeutic effect of radiation ( 18 ).…”

Rare Signet Ring Cell Adenocarcinoma of the Colon Metastasis to the Orbit

“…However, the tumors reported by Khawaja et al arose exclusively from colorectal adenocarcinomas and none of the cases were signet ring cell carcinomas. Orbital metastasis of other subtypes of colorectal carcinomas has also been observed [13][14][15]. Signet ring cell tumors are an uncommon tumor subtype comprising between 0.1% and 2.4% of all colorectal carcinomas [16].…”

Orbital metastasis mimicking internuclear ophthalmoplegia: A case report and review

“…1,15 In contrast, colorectal cancer metastases to the orbit are rare, with only 13 cases reported in the world literature ( Table 1). [1][2][3][4][5][6][7][8][9][10][11][12][13] Of the 13, only 6 cases involve rectal carcinoma as the primary tumour. However, it has been hypothesized that gastrointestinal carcinoid tumours have a propensity to metastasize to the extraocular muscles.…”

“…To our knowledge, there are only 13 other reports of orbital metastasis resulting from colorectal cancer (of which only 6 were rectal cancer). [1][2][3][4][5][6][7][8][9][10][11][12][13] We believe that this is the first reported case mimicking an apparent INO.…”