GI manifestations of mantle cell lymphoma

MegaAppendix: a rare case of mantle cell lymphoma in an appendix presented as volvulus

Mantle cell lymphoma (MCL), representing 5% of cases, is an aggressive B-cell non-Hodgkin lymphoma. Rarely, it can spread to other areas. This case illustrates a unique occurrence of MCL involving the appendix, leading to obstructive symptoms. Additionally, its presentation as volvulus added complexity to diagnosis and treatment. A 72-year-old man with a history of MCL came to the ER with right lower quadrant abdominal pain and nausea for 7 days. A computed tomography scan showed a swirling sign, concerning for volvulus. The patient required emergent surgery for exploratory laparotomy. Intraoperatively, the patient was found to have an enlarged appendix measuring 16.5 cm in length and 5 cm in diameter. An appendectomy was performed, and the pathology was confirmed to be MCL. This is a rare case of MCL presenting in the appendix as a volvulus, resulting in obstructive symptoms. This distinctive manifestation posed significant challenges in diagnosis and management. Appreciating such cases is pivotal for accurate diagnosis and effective medical and surgical interventions for this aggressive lymphoma subtype.

Mantle cell lymphoma-rare differential diagnosis of a tumor in the vermiform appendix

Although the most common localization of extranodal non-Hodgkin lymphoma is the gastrointestinal system, the infiltration of the vermiform appendix is a very rare condition. We report a case of mantle cell lymphoma affecting the appendix as an incidental finding due to gynecological surgery. A 57-year-old woman presented with increasing pain in the right lower abdomen since months. During gynecological evaluation an inhomogenous mass in the right ovarian place was noticed and misinterpreted as ovarian tumor. Laparoscopic ovarectomy was planned. The intraoperative situs showed surprisingly a massive enlarged appendix and completely normal ovaries. Since the lesion was suspicious for appendiceal cancer, a right hemicolectomy was performed. Histopathology revealed a non-Hodgkin lymphoma with immunohistochemical proof of blastoid B-cells, a mantle cell lymphoma. Polychemotherapy was administered.

DNA Methylation of Tumor Suppressive miRNAs in Non-Hodgkin's Lymphomas

DNA methylation is an epigenetic alteration leading to heritable phenotypic changes of cells with functional consequences. It is important in early embryonic development, stem cell differentiation, and tissue-specific gene expression. In normal cells, promoter-associated CpG islands (CGI) are generally unmethylated except in X-chromosome inactivation or genomic imprinting. In cancer, tumor cells are characterized by global hypomethylation but locus-specific hypermethylation of promoter-associated CGI, resulting in gene silencing. MicroRNAs (miRNAs) are short, non-coding RNA sequences of 18-25 nucleotides, which can repress the translational of multiple protein-coding mRNAs by sequence-specific binding to the 3'untranslated region. Depending on the genes targeted, miRNA can be tumor suppressive if an oncogene is repressed, or it can be oncogenic when a tumor suppressive gene is repressed. Recently, aberrant methylation of tumor suppressive miRNAs has been reported in different types of cancers including lymphomas. Herein, we review the recent literature of methylation of tumor suppressive miRNAs in different histopathologic subtypes of lymphomas, and discuss its potential diagnostic, prognostic, and therapeutic significance.