Pseudohypopyon as a Feature of Multiple Myeloma

Multiple myeloma is a malignancy of the immune system that infrequently involves the eye. Cysts of the ciliary body and retinal vascular lesions represent the most common ocular manifestations in myeloma patients.¹ This report documents the first case of anterior chamber infiltration–simulating hypopyon (pseudohypopyon) in multiple myeloma.

A 72-year-old white man was referred by his hematologists for anterior segment evaluation. Hyperemia and soreness of his left eye, accompanied by blurred vision, had been noted over the preceding 3 weeks. The patient had been diagnosed with multiple myeloma 2 months previously following prolonged fatigue, acute renal insufficiency, and high levels of serum calcium and IgG. Subsequently, he received 3 courses of vincristine sulfate, doxorubicin hydrochloride, and methylprednisolone (VAMP) chemotherapy, which resulted in considerable decrease of the paraprotein (IgG). His ocular symptoms developed 2 weeks after the last course of chemotherapy, while he was taking oral amitriptyline hydrochloride, ciprofloxacin hydrochloride, and acyclovir.

On examination, his corrected visual acuity was 20/30 OD and 20/40 OS. Both corneas were clear, and his left conjunctiva was hyperemic, although there was no conjunctival venous sludging. His left pupil was slightly irregular, and there was evidence of low-grade anterior chamber activity (indicated by a few cells and mild flare) with secondary localized posterior synechiae. However, the most striking clinical abnormality was a white, solid, well-demarcated pseudohypopyon of undetermined source occupying the inferior anterior chamber and slightly extending medially (Figure 1). There was no evidence of crystals within the cornea or infiltration of the iris. Intraocular pressures were within normal limits, and ophthalmoscopy results were unremarkable in both eyes, with the absence of retinal venous stasis, cotton-wool spots, or optic disc swelling. Although the lesion was simulating a hypopyon, there was no strong evidence of an infective underlying cause, so the patient began taking mild topical steroids (0.5% prednisolone ophthalmic drops, 4 times daily). A sample of the infiltrate was obtained through a corneal paracentesis. Cytology results confirmed the presence of monoclonal plasma cell infiltration. The patient underwent 10 courses of radiotherapy to the left orbit with subsequent complete resolution of the pseudohypopyon (Figure 2). After treatment began, the cellular activity in the anterior chamber and the pseudohypopyon resolved, and the patient's visual acuity improved to 20/30 in the affected eye.

Multiple myeloma is the most common of the plasma cell dyscrasias characterized by monoclonal gammopathy and osteolytic bone lesions.² Ocular involvement in patients with multiple myeloma has been well described.¹ The ocular manifestations may be divided into 2 groups: those attributable to myeloma infiltration in and about the eye, and the ocular consequences of hematologic and serum protein abnormalities.³ Bronstein⁴ reported plasma cells floating free in the anterior chamber and adhering to the posterior cornea. Infiltration of the iris has also been reported, simulating a nongranulomatous uveitis.⁵ However, to our knowledge, this is the first report of a myeloma patient with a well-formed, solid infiltrate in the anterior chamber that resembles a hypopyon (pseudohypopyon). A pseudohypopyon is characterized by its persistence and irregular contour, which suggest clumping of neoplastic cellular material rather than the layering of neutrophils, as in anterior uveitis.

Resolved blood remnants and neoplastic infiltrates may give rise to a comparable appearance. Neoplastic infiltrates can be caused by acute or chronic leukemias or juvenile xanthogranuloma, or they may be an atypical manifestation of retinoblastomas. In addition, metastatic carcinomas of the iris, which typically appear as solid, amelanotic masses, occasionally are discohesive and shed cells that form a hypopyon in the anterior chamber.^6,7

Treatment of multiple myeloma is predominantly directed toward the systemic disease, and chemotherapy and radiotherapy are very effective in reducing the tumor mass.⁸ In our patient, radiotherapy resulted in complete resolution of the anterior chamber infiltrate with subsequent improvement of his visual acuity.

Our case of a solid anterior chamber infiltrate broadens the clinical spectrum of multiple myeloma and emphasizes that tumor infiltrates should be considered in the differential diagnosis of any atypical hypopyon. Close cooperation between the oncologists and ophthalmologists who treat such patients is mandatory for prompt diagnosis and effective management.

Corresponding author and reprints: Paris G. Tranos, ICO, Department of Ophthalmology, Royal Free Hospital Medical School, Pond Street, London NW3 2QG, England (e-mail: ptranos@hotmail.com).