Investigation

As with lymphomas in other sites, detailed investigation is necessary to determine the stage of the disease before a definitive treatment plan is established.19 A thorough staging workup is necessary to identify patients with orbital lymphoma who may harbor additional foci of lymphoma throughout the body, thus requiring systemic or combined-modality treatment.

A complete history and physical examination may provide evidence of systemic, although clinically silent, disease or presence of constitutional signs. In addition to a usually painless and nontender orbital

FIGURE 13.2. Axial noncontrast, T1-weighted magnetic resonance image of an intraconal lymphoma in the posterior left orbit (asterisk).

TABLE 13.1. Primary vs Secondary Orbital Lymphomas.

Primary lymphomas

Secondary lymphomas

Characteristics

Location

Histology

Isolated, extranodal, orbit is often the first site of lymphoma involvement Usually unilateral

Most common in 50- to 70-year-old age group M = F

Low-grade, indolent, small lymphocytic, follicular, or MALT

Disseminated, systemic involvement, may appear late as part of generalized relapse Usually unilateral

Most common in 50- to 70-year old age group, but younger patients more likely to have high-grade lymphomas M = F

More often intermediate- or high-grade (diffuse mixed or large cell type) but low-grade secondary orbital lymphomas also common

mass, which may be palpable or visible during the examination, there may be visual loss due to compres-sive optic neuropathy, a condition revealed by a thorough ophthalmic examination.

Box 13.3 summarizes the recommended staging workup for orbital lymphomas. An imaging study of the orbit is critical in delineating the extent of orbital involvement. A characteristic diffuse to moderately

FIGURE 13.3. Histologic findings for the lacrimal gland mass shown in Figure 13.1. (A) Histologic section (with H&E stain) demonstrates a mostly follicular lymphoma with areas of diffuse infiltration by a mixture of small cleaved and large noncleaved lymphoid cells. (B) Immunohistochemical staining of paraffin-embedded tissue sections demonstrates that the lymphoma cells are positive for CD20, confirming B-cell lineage.

FIGURE 13.3. Histologic findings for the lacrimal gland mass shown in Figure 13.1. (A) Histologic section (with H&E stain) demonstrates a mostly follicular lymphoma with areas of diffuse infiltration by a mixture of small cleaved and large noncleaved lymphoid cells. (B) Immunohistochemical staining of paraffin-embedded tissue sections demonstrates that the lymphoma cells are positive for CD20, confirming B-cell lineage.

well-defined orbital mass with molding to the globe, optic nerve, and orbital bones strongly suggests the diagnosis of orbital lymphoma (Figure 13.4). On computed tomography, lymphomas appear homogenous in texture and isodense to muscle, showing mild enhancement with contrast.

Fine-needle cytology or open biopsy of orbital and adnexal masses is often necessary to confirm the diagnosis and help with the histologic classification of orbital lymphomas.

Imaging studies of the abdomen, thorax, and pelvis are performed to rule out disseminated disease. A bone marrow aspiration is performed to rule out marrow involvement. Upper GI tract endoscopy and barium studies are done to detect gastrointestinal involvement and are particularly important for certain subtypes of orbital lymphoma, such as mantle cell lymphoma with a predilection for gastrointestinal involvement.

PET is replacing bone and gallium scans for detecting small foci of lymphoma throughout the body.

0 0

Post a comment