Dear Editor:

Colonoscopy was performed to a 65-year-old female with tenesmus that showed, in the distal rectum, a bulging lesion of 3 cm covered with normal appearance mucosa.

We performed an endoscopic ultrasonography (EUS) that showed a polypoid morphology lesion, heterogeneous, mainly hypoechoic, located in the deep mucosa and submucosa layers; the lesion was well delimited with regular borders and occupied one third of the rectum circumference. There was no sure diagnosis, being most likely a fibrolipoma, a granular cell tumor, a neuroendocrine tumor, or a fibrovascular polyp. It was proposed to the patient to perform a transanal resection or an EUS with fine needle aspiration. She accepted the transanal resection.

She had history of a nodal non-Hodgkin lymphoma treated 3 years before with rituximab, cyclophosphamide, vincristine, and prednisolone and a surgical treatment of urogenital prolapse 1 year before using a plastic prosthesis.

The histopathologic examination revealed a rectal follicular lymphoma, grade one. The staging procedures showed no other site of disease.

Discussion

Although the gastrointestinal tract is one of the most common extranodal sites, the frequency of colon and rectum lymphoma, primary or involved by systemic disease, is rare [1]. It was not considered as a hypothesis due to its rarity and the fact that the patient had been disease-free during several years. It usually presents endoscopically as fungating, ulcerative, infiltrative, ulcerofungating, and ulceroinfiltrative types, being fungating and ulcerofungating the most frequent [2]. There are few cases reporting appearance as a submucosal lesion, and to our best knowledge, none of them was a follicular lymphoma [3]. A lymphoma involving the colon and rectum is rare and can occur either as a primary colorectal lymphoma or as a manifestation of systemic disease.

A high suspicious level of extranodal lymphoma site is necessary for detecting neoplastic lesions. The rectal lesion was not characteristic of a rectal lymphoma; thus, the surgery resection was vital.