This case has a unique presentation, showing gastrointestinal symptoms, which was initially misleading. To the best of our knowledge squamous cell carcinoma arising from an ovarian dermoid cyst presenting as a Regorafenib nmr rectal mass with gastrointestinal symptoms has not been previously reported. This case emphasizes the importance of the guidelines suggested by William et al, in the evaluation of patients with colorectal SCC. Since primary SCC of the colorectal are rare, other primary sites and an extension from the anal canal should always be considered.

Footnotes No potential conflict Inhibitors,research,lifescience,medical of interest.
A 55 year old postmenopausal woman presented with vaginal spotting which rapidly progressed to more severe bleeding. On examination she was found to have a mass Inhibitors,research,lifescience,medical in the vaginal vault which was close to, but not attached to, the cervix. Excisional biopsy of the lesion in the vaginal wall and biopsies of the endometrium, along with cervical conization revealed adenocarcinoma in the vaginal lesion only (Figure 1). Immunostains were performed and these showed a pattern which was most compatible with intestinal Inhibitors,research,lifescience,medical differentiation (CK20

and CDX-2 positive, CK7 focally positive (less than 5% of cells), ER and PR both negative, P16 and CEA variably positive) (Figure 2). The Tissue of Origin Test®, run on micro dissected tumor tissue, showed the highest similarity score of 91.1 for a colo-rectal origin. The Inhibitors,research,lifescience,medical 14 other tissue types in the panel had similarity scores of less than or equal to 5. CT scan and MRI of the abdomen and pelvis showed several cavernous hemangiomas and cysts in the liver but there was no evidence of any residual or metastatic disease. PET scan was also unremarkable. Additional history of Hirschprung disease (HD) as a child, which had required surgical correction (with complications of obstruction and fistula formation at age 19 which were addressed with additional

surgery), Inhibitors,research,lifescience,medical was obtained. Anorectal examination was grossly unremarkable and random biopsies showed mucosa consistent with a squamous papilloma but with no evidence of malignancy. Colonoscopy was normal. Of note, her CEA level at this time was found to be elevated at 35 ng/ml (normal range 0-5 ng/ml). and Figure 1 Section shows high power view of a well-differentiated adenocarcinoma displaying a complex glandular arrangement with some micro-papillary architecture. The cells lining the glands are columnar and have mucinous cytoplasm. There are scattered goblet cells. … Figure 2 Positive CK20 immunohistochemical (IHC) stain. Family history was significant for colorectal cancer in her mother and grandfather and endometrial and appendiceal cancer in a cousin. Her brother had also been treated for HD. At this time she was referred to medical oncology. Physical examination, including a pelvic exam and careful exam of the thyroid, was unremarkable.