Peripheral T-Cell Lymphoma Mimicking Marginal Zone B-Cell Lymphoma

Abstract

Peripheral T-cell lymphoma (PTCL) may assume a variety of histologic and cytologic appearances. We describe eight cases of PTCL morphologically simulating marginal zone B-cell lymphoma. We reviewed PTCL cases diagnosed in our institution between 1990 and 2000 and selected eight cases for study based on the following criteria: small-cell morphology with abundant, clear cytoplasm and either marginal zone involvement by the neoplastic infiltrate in lymph node biopsies or lymphoepithelial lesions in extranodal biopsies. Histologic features and ancillary studies were reviewed. Patients included six women and two men with a median age of 53 years (range, 35 to 74 years). Six patients were diagnosed with primary nodal PTCL, and two presented with primary extranodal disease. The original diagnosis was PTCL in only four cases; three cases were diagnosed as atypical lymphoid infiltrate, and one case as benign lymphoepithelial lesion. Lymph node biopsies revealed partial effacement of the architecture with residual follicles surrounded by the neoplastic small cells. Extranodal sites included hard palate, tongue, tonsil, and submandibular glands; all but one case demonstrated lymphoepithelial lesions. Monoclonality was demonstrated in six of eight cases (rearrangement of T-cell receptor gene), and three of eight had an aberrant T-cell population by flow cytometry. The differential diagnosis of atypical lymphoid infiltrates with morphologic features of marginal zone B-cell lymphoma should include PTCL. This uncommon morphological mimicry should be recognized, because PTCL is an aggressive disease regardless of morphology and should be treated accordingly.

Cytologic findings of marginal zone lymphoma

“…Uherova et al studied histologic specimens from eight patients that included six lymph node biopsies and four extranodal biopsies composed of uniform, small-to-intermediate-sized, lymphoid cells with round or slightly irregular nuclei and abundant pale or clear cytoplasm. 39 However, in all specimens, the neoplastic cells were positive for CD3 by immunohistochemistry. The six specimens in which gene rearrangement studies were performed showed monoclonal gene rearrangement of the T-cell receptor ␤ chain in the absence of immunoglobulin gene rearrangement.…”

Nodal follicular helper T-cell lymphoma may present with different patterns. A case report

“…Our case shows that the same clone of T cell expressing a phenotype similar to that of normal follicular helper T cells may present with different patterns: AITL, a condition well known [1][2][3]6]; FTCL, a less frequent condition [7][8][9][10][11][13][14][15]; and PTCL-unspecified, large-cell predominant.…”

Canine Indolent Nodular Lymphoma

“…The report that human peripheral T-cell lymphoma (TZL) may mimic MZL is highly applicable to the dog. 49 A subtle difference in architecture exists between MZL where the proliferation is concentric and encircles the fading germinal centers, whereas in TZL, the proliferation is eccentric to the residual B-cell foci.…”

“…7a). 22,36,45,49 Cytologically, TZL is composed of homogeneous population of CD3 + small lymphocytes that have sharp, shallow nuclear indentations, inapparent nucleoli, and a moderate volume of pale cytoplasm (Fig. 7b).…”