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Sonographic Appearance of Primary Lacrimal Sac Lymphoma

Tumors of the lacrimal drainage system are very rare, and more than 90% of the tumors in various series are of epithelial origin.1 Primary lymphoma of the lacrimal sac is rare and can sometimes be misdiagnosed. Lymphomas that give rise to nasolacrimal duct obstruction generally originate from within the lacrimal sac.2 Both computed tomography and magnetic resonance imaging may be used in the diagnosis of lacrimal drainage system tumors. However, sonography in the diagnosis of these tumors can also provide useful information. The goal of this report is to emphasize the importance of sonographic scans in the diagnosis of lacrimal sac lesions. A 14-year-old male patient presented with a slightly painful swelling in the left medial orbital canthus that had increased steadily in size over a 2-month period. Initially, the patient consulted an outside general practitioner, who made the diagnosis of dacryocystitis and prescribed medical treatment. However, the painful swelling persisted, along with epiphora. Because his symptoms were getting worse despite medical treatment for dacryocystitis, he was referred to the ophthalmology clinic of our hospital. Physical examination revealed a 2.5-cm mass in the left medial canthus. Sonography showed a solid mass with an irregular border on the left medial orbital canthus (Figure 1A). On B-mode and Doppler sonography, the periphery of the mass was heterogeneously hypoechoic and hypervascular, but there was a central region that was hyperechoic and avascular (Figure 1B). We think that this hyperechoic area on sonography may have represented fat engulfed by the tumor tissue. Computed tomography of the orbits confirmed a solid, comparatively well-defined ovoid mass that was homogeneous in appearance and expanding the nasolacrimal duct (Figure 1C). The lesion showed diffuse homogeneous enhancement and measured 1.1 × 1.5 × 2 cm. No evidence of bone destruction or invasion was noted. A subcutaneous incisional biopsy of the lesion for pathologic examination was performed. Histopathologic examination showed small and medium-sized atypical lymphoid cells with irregular hyperchromatic nuclei. Results of immunohistochemical studies showed that the lymphoid tumor cells were strongly positive for CD20 but negative for CD3 and CD5 (Figure 1, D and E). Thus, after incisional biopsy, low-grade B-cell lymphoma was diagnosed. The patient had surgery at another hospital in the same city. After complete removal of the tumor, excisional biopsy results confirmed extranodal B-cell lymphoma as the diagnosis. A history of epiphora, bloody tears, and a fastgrowing solid lesion suggests the existence of a tumor in the lacrimal drainage system in the differential diagnosis.3 Dacryocystitis is the most frequent disease associated with dysfunction of the lacrimal drainage system. However, with prolonged dacryocystitis, the possibility of neoplastic disease should be kept in mind. Clinical suspicion of a lacrimal sac tumor