IntroductionColorectal lymphomas represent only 5% to 10% of gastrointestinal lymphomas, after the stomach and small intestine. Primary lymphoma of the colon and rectum is an unusual observation, constituting only 0.2% to 0.5% of all malignant tumors arising from the colorectal region. Very little is known about the correlation between adenoma and lymphoma in the colorectal tract. We report here a rare case of diffuse large B-cell lymphoma developing within a solitary tubular adenoma with low-grade dysplasia of the rectum.Case presentationAn 83-year-old Caucasian man was referred to our hospital intermittent anal bleeding and irregular bowel. Colonoscopy revealed a 1cm solitary rectal polyp, which was completely removed by endoscopic resection. Histologic studies revealed low-grade intraepithelial dysplasia; the stroma of adenoma showed focal localization by highly proliferative lymphoid cells. Immunohistochemical analyses demonstrated that lymphoid cells were positive for CD20 and bcl2, whereas they were negative for CD3, CD5, CD10, CD23, CD30, CD138 and cyclin D1. Approximately 90% of the neoplastic cells reacted positively when stained with an antibody to Ki-67. Molecular studies showed the presence of a monoclonal immunoglobulin heavy chain gene rearrangement.To determine primary or secondary lymphoma localization, Dawson’s criteria were applied to the case. A diagnosis of primary diffuse large B- lymphoma Ann Arbor stage 1A was established. Subsequently, the patient was referred to oncology to establish the stage and to select appropriate treatment.ConclusionsThe case of diffuse large B-cell lymphoma developing within a tubular adenoma, as reported here, is considered a rare event. Little about the prognosis of primary colorectal lymphomas is available and therapeutic treatment protocol is unclear. This case report provides more information on the history and macroscopic appearance of lymphomas presenting in an unusual location. To report additional cases in the future would be helpful in redefining the diagnostic, prognostic and therapeutic approach.

Background Crohn's disease (CD) and ulcerative colitis, two forms of inflammatory bowel disease (IBD), are chronic and relapsing conditions of the gastrointestinal tract both characterized by long lasting chronic inflammation and increased risk of dysplasia and colorectal cancer (CRC). The aim of our study was to evaluate the interobserver agreement about IBDassociated dysplasia among pathologists belonging to the Italian Group for Inflammatory Bowel Diseases (IG-IBD P). Methods The present multicenter survey was performed using telepathology, supported by an open source E-learning platform. Biopsy specimens from 30 colonoscopies and from 20 patients were included. The glass slides of any case, including clinical and endoscopic data, were digitalized and uploaded on the E-learning platform. All the digital slides were grouped in 54 diagnostic "blocks". Blinded histopathological evaluation on all the digital slides was performed by 20 gastrointestinal pathologists. Closed-ended questions about (1) the occurrence of IBD; (2) the classification of IBD (as UC or CD); (3) the presence of active versus quiescent disease; (4) the presence of dysplasia; (5) the possible association of dysplasia with the sites of disease (dysplasia-associated lesion or mass-DALM vs adenoma-like mass-ALM); (6) the grading of dysplasia according to the ECCO guidelines (negative, indefinite, low grade, high grade categories) and (7) the presence of associated serrated features, were proposed in each case. Inter-observer agreement was evaluated by mean agreement percentage and kappa statistic, when suitable. Results The diagnosis of IBD was confirmed in 19 of 20 patients, 17 of 19 being classified as UC, 2 as CD. The mean interobserver agreement percentages about (1) the evidence of IBD, (2) the presence of either UC or CD and (3) the activity grading resulted to be 80%, 69% and 86%, respectively. Dysplasia was detected in 8/20 patients, with moderate agreement between pathologists (mean 72%, k 0.48). Particularly, low grade dysplasia was found in 13 biopsies (combined k 0.38), whereas high grade dysplasia in 8 (combined k 0.47). When the endoscopic and histopathological data were combined, features consistent with DALM were found in 6 of 20 patients with low grade dysplasia and those consistent with ALM in 2 patients with low grade dysplasia in a single biopsy (mean agreement: 86%). An associated serrated pattern was discovered in 4 patients (7 biopsies). Conclusions Our study showed moderate interobserver agreement about the histopathological detection and classification of IBD-associated dysplasia. Further efforts should be undertaken to integrate the histopathological data with both the ancillary tests and molecular investigations.

IntroductionNon-Hodgkin lymphoma (NHL) can involve the paratesticular organs as the primary disease, as primary testicular lymphoma that secondarily involves the paratesticular structures, as the initial site of presentation of occult nodal disease or as the result of disease dissemination. Primary follicular lymphoma of the epididymis in an adult is extremely rare. Little is known about primary adult paratesticular/epididimal lymphomas.Case presentationWe report a rare case of primary follicular non-Hodgkin lymphoma of the epididymis in a 90-year-old Caucasian man who presented with a left scrotal mass. Bone marrow biopsy was negative and computed tomography of the total body revealed no evidence of extratesticular involvement. Macroscopically, the epididymis was replaced completely by a uniform mass. Histologic studies revealed a dense lymphoid infiltrate predominantly composed of centrocytes with admixed centroblasts. Immunohistochemical analyses demonstrated that neoplastic cells strongly expressed CD45RB, CD20, CD79a, bcl-6 and CD10; bcl-2 immunostaining was negative. Molecular studies showed the presence of the monoclonal IgH gene rearrangement and the IgH/BCL2 rearrangement. The lymphoma was classified as follicular lymphoma, low grade, grade 1-2. The patient subsequently underwent radical orchiectomy, did not receive chemotherapy and post-operative follow-up showed absence of disease recurrence.ConclusionsThe case of primary follicular lymphoma of epididymis, reported here, is considered a very rare event. It is characterized by clinically indolent localized disease, a good clinical outcome, lack of expression of BCL2 protein and the presence of the t(14;18)(q32;q21)/IGH-BCL2. Even if it is a single case, the primary follicular lymphoma epididymis with t(14;18) could represent either a variant of the previously reported t(14;18)-negative primary paratesticular follicular lymphoma or a distinct biological entity. To report additional cases in the future would be helpful in resolving this question.