FINAL DIAGNOSIS: MANTLE CELL LYMPHOMA INVOLVING THE INTESTINE AT THE ILEOCECAL JUNCTION
This patient was previously diagnosed with mantle cell lymphoma with bone marrow involvement.
Mantle cell lymphoma is a neoplasm of B-lymphocytes, composed of small to intermediate-sized cells with variably irregular nuclei, dispersed chromatin, inconspicuous nucleoli, and scant cytoplasm. It accounts for approximately 5 to 10% of non-Hodgkin lymphomas and occurs in older individuals (median age 60) with a male predominance. The most common involved sites are lymph nodes, followed by spleen, bone marrow, the gastrointestinal tract, and Waldeyer's ring. Most patients present with advanced disease with lymphadenopathy, splenomegaly, and bone marrow involvement.
The neoplastic lymphocytes are typically strongly CD20 positive, CD5 positive, CD10 negative, bcl-6 negative, CD23 negative, FMC-7 positive, CD43 positive, and bcl-2 positive. Nearly all cases express cyclin D1. The t(11;14)(q13;q32) translocation with rearrangement of the CCND1 (PRAD1, encodes cyclin D1 or bcl-1) and IGH (encodes immunoglobulin heavy chain) genes can be detected by conventional cytogenetics, Southern blot analysis, and/or fluorescent in-situ hybridization in almost all cases.
In the presented case, the neoplastic cells were negative for FMC-7. Although rare, there are reported cases of mantle cell lymphoma lacking FMC-7 expression. The hallmark phenotypic findings are positive immunohistochemical staining for cyclin D1 and/or the presence of the t(11;14)(q13;q32) translocation by cytogenetic or molecular diagnostic methods. Therefore, the lack of FMC-7 expression in this case is an acceptable phenotypic variation.
Mantle cell lymphoma demonstrates features of both low-grade and high-grade non-Hodgkin lymphomas. The vast majority of patients cannot be cured, as with low-grade lymphomas. However, the clinical course is more rapid than in low-grade non-Hodgkin lymphomas, with a median survival of 3-5 years. The literature is somewhat controversial in regard to prognostic features; advanced stage disease, B symptoms, poor performance status, and bone marrow involvement are reported as adverse prognostic indicators. A high mitotic rate is the most frequently reported histologic feature for determining prognosis.
As mentioned earlier, the gastrointestinal tract is a common extranodal site for mantle cell lymphoma and is involved in about 20% of cases. The presenting signs and symptoms are nonspecific and can be attributed to the site of involvement. The major gastrointestinal sites of involvement by mantle cell lymphoma are the ileocecal junction (36%), ileum (20%), rectum (9%), and duodenum (8%). Lesions can present endoscopically as a discrete tumor mass (85%), a diffusely infiltrating lesion with erosion (8%), multiple polyps (multiple lymphomatous polyposis, 4%), or a single ulcer (1%).
Contributed by by J. Manuel Zarandona, MD and Fiona E. Craig, MD