Cutaneous Spindle-Cell B-Cell Lymphoma

Abstract

The morphologic spectrum of large B-cell lymphoma is broad. Several unusual variants have been described such as lymphoma with myxoid stroma, sclerosing B-cell lymphoma, signet ring-cell lymphoma, and multilobated B-cell lymphoma among others. We report on five cases of cutaneous large B-cell lymphoma in which the neoplastic cells were spindle-shaped. In two cases, the clinical features fulfilled those of a primary cutaneous lymphoma; in the three other cases, the lymphoma most likely arose primarily in the skin, but incomplete clinical workups precluded definite categorization. The patients ranged in age from 30 to 89 years and presented with solitary lesions on the trunk or head. Histopathologic examination revealed nodular or dense diffuse infiltrates involving the entire dermis as well as the subcutaneous fat in some cases. Thickened collagen bundles between the spindled cells were present in one case. Cytomorphologic analysis showed the presence of round or oval medium-sized and large-sized lymphocytes with features of centrocytes and centroblasts in some foci, with others dominated by cells with spindle-shaped, elongated, twisted nuclei with dispersed chromatin and scant cytoplasm. Immunohistologic analysis revealed that both round or oval and spindled cells were positive for CD20 in all cases; in all cases tested, these cells were also positive for MIB-1 and were negative for CD3, CD5, CD43, CD45RO, CD21, CD30, CD68, S-100, HMB-45, actin, smooth-muscle actin, and cytokeratin. Bcl-2 was expressed in one of three cases tested. Analysis of the rearrangement of the J(H) gene by polymerase chain reaction performed in one case showed a monoclonal pattern. Spindle-cell large B-cell lymphoma represents a distinctive rare subtype of the cutaneous large B-cell lymphoma and can arise primarily in the skin in some cases. Recognition of this variant is necessary to avoid misdiagnosis of other cutaneous malignant spindle-cell tumors.

A literature revision in primary cutaneous B-cell lymphoma

“…Age, growth rate, and location of biopsied lesions influenced the framework of histological presentation. [9124956] Small and early lesions contain a mixture of centrocytes, relatively few centroblasts, and many reactive T-cells. Early infiltrates may have a patchy perivascular and periadnexal growth pattern, a common diagnostic pitfall of a reactive infiltrate or “pseudolymphoma.”[575859] With the progression of lesions to tumor, neoplastic B-cells increase in both number and size whereas the number of reactive T-cells steadily decreases.…”

“…[56] The abnormal follicles are composed of malignant BCL-6 follicle center cells enmeshed in a network of CD21 or CD35 follicular dendritic cells. The follicles are ill-defined mantle zone that is frequently reduced or absent and lacks on tingible body macrophages.…”

“…The follicles are ill-defined mantle zone that is frequently reduced or absent and lacks on tingible body macrophages. [5661] In tumorous skin lesions, follicular structures are no longer visible, except for occasional scattered CD21 or CD35 follicular dendritic cells. Generally, a monotonous population of large centrocytes and multilobulated cells, and in rare cases, spindle-shaped cells, with a variable admixture of centroblasts and immunoblasts is present.…”

“…[251949505660] PCFCL is an indolent disease, even if left untreated, skin lesions may be stable, gradually increase in size over years, or regress in rare cases. Dissemination to extracutaneous sites remains an exceptional event (it occurs in 5%–10% of cases).…”

PAX8 Distinguishes Diffuse Large B-Cell Lymphoma Mimicking Sarcoma

“…In most reported cases, the spindle cell variant of diffuse large B-cell lymphoma is positive for the B-cell marker CD20 with coexpression of bcl-6 in a subset of reported cases, consistent with follicular center cell derivation [12–14]. Up to 56% of cases with spindle cell morphology have been reported to express at least focal smooth muscle actin (SMA) [12, 13, 15]. …”