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.

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.

Introduction: Epithelioid cell granulomas into neoplastic tissues have been reported in association with a wide series of neoplasms, including lymphomas. Epithelioid granulomas in association with non-Hodgkin's lymphomas are only rarely observed. When granulomas are present in association with lymphomas, they are usually non necrotizing, sarcoid-like.Little is known about the association of granulomatous reaction with anaplastic large cell lymphoma (ALCL) and to the best of our knowledge anaplastic large-cell lymphoma with histological features of necrotizing granulomatous lesion has not been reported previously in the literature. In this article we report a case of anaplastic large-cell lymphoma mimicking a necrotizing granulomatous lymphadenitis. Case Presentation Section:A 55-year-old Caucasian man presented with a 3-month history of a painless, enlarged, lymph node localized on the left inguinal region. Escissional biopsy was performed. The microscopic examination led to the diagnosis of granulomatous lymphadenitis with necrosis.Two months later the patient returned because he had note the appearance of a nodule in the right axillary region.Following the escissional biopsy, the histological examination and the immunohistochemical stains have been made the diagnosis of ALCL, ALK1 negative. The first case was revaluated. Extensive immunophenotypic characterization (positivity for CD45RO/UCHL1 and CD-30 in the areas of necrosis), in conjunction with histomorphologic and molecular analysis (presence of a T monoclonal cell lymphoid), established diagnosis of ALCL ALK-1 negative. Conclusions:The presence of exaggerated granulomatous reaction in tissue involved by lymphomas may mask neoplastic lymphoid cells and result in erroneous histopathologic diagnosis.In this article we report a case of primary nodal ALCL mimicking a necrotizing granulomatous lymphadenitis.