Paraproteinemic corneal deposits in plasma cell myeloma

Prevalence of corneal findings and their interrelation with hematological findings in monoclonal gammopathy

PURPOSE

To determine prevalence of paraproteinemic keratopathy (PPK) among patients with monoclonal gammopathy (MG). To evaluate interrelation between corneal and hematological parameters in patients with PPK.

METHODS

Fifty-one patients with monoclonal gammopathy of undetermined significance (n = 19), smoldering multiple myeloma (n = 5) or multiple myeloma (n = 27) were prospectively included in this study. Best-corrected visual acuity, slit-lamp biomicroscopy, Scheimpflug tomography, in-vivo confocal laser scanning microscopy, optical coherence tomography and complete hematological workup were assessed.

RESULTS

We identified n = 19 patients with bilateral corneal opacities compatible with PPK. PPK was newly diagnosed in 13 (29%) of 45 patients with a primary hematological diagnosis and in n = 6 patients without previous hematological diagnosis. The most common form was a discreet stromal flake-like PPK (n = 14 of 19). The median level of M-protein (p = 0.59), IgA (p = 0.53), IgG (p = 0.79) and IgM (p = 0.59) did not differ significantly between the patients with and without PPK. The median level of the FLC κ in serum of patients with kappa-restricted plasma cell dyscrasia was 209 mg/l in patients with PPK compared to 38.1 mg/l in patients without PPK (p = 0.18). Median level of FLC lambda in serum of patients with lambda-restricted plasma cell dyscrasia was lower in patients with PPK compared to patients without PPK (p = 0.02).

CONCLUSION

The PPK was mostly discreet, but its prevalence (29%) was higher than expected. Median level of the monoclonal paraprotein was not significantly higher in patients with PPK compared to patients without PPK. Our results suggest a lack of correlation between morphology and severity of the ocular findings and severity of the monoclonal gammopathy.

TRIAL REGISTRATION

German Clinical Trial Register: DRKS00023893.

Monoclonal gammopathy of "ocular" significance

Purpose

Diagnostic criteria for monoclonal gammopathy of undetermined significance (MGUS) do not currently include ocular phenotypic changes. Here, we offer a new diagnostic approach that is useful in patients with posteriorly located corneal depositions and present evidence to support the theory that the aqueous humor is a source for monoclonal proteins accumulated in the cornea.

Observations

A 77-year-old woman presented to the clinic with a gradual decrease in visual acuity over 6 months. Slit lamp examination revealed bilateral central guttae consistent with Fuchs corneal dystrophy, peripheral circular band-like corneal opacities in the deep stroma, and bilateral nuclear sclerotic and cortical cataracts. Anterior segment optical coherence tomography confirmed corneal opacities in the posterior stroma and Descemet membrane. Immunological studies revealed increased serum IgG levels of 3220 mg/dL and serum electrophoresis showed an abnormal monoclonal band of 2.4 g/dL identified as IgG lambda by immunofixation electrophoresis. The patient was referred to the hematology clinic where she underwent further systemic workup and was diagnosed with MGUS. Immunofixation electrophoresis of aqueous sampling, which was performed at the time of cataract surgery, confirmed the presence of the IgG lambda gammopathy in the anterior chamber.

Conclusions and importance

Monoclonal gammopathy, although rare, should be included in the differential diagnosis of corneal opacities, as the ocular finding can be the initial manifestation of a systemic disease that can potentially be life-threatening. When corneal biopsy is not feasible due to the location of corneal pathology, aqueous sampling may be an alternative approach towards a clinical diagnosis. We propose a new terminology, “monoclonal gammopathy of ocular significance,” for patients diagnosed with MGUS, however, their only significant clinical finding is ocular manifestation.

Ocular Pathology in Light Chain Deposition Disease

Light-chain deposition disease (LCDD), a rare form of monoclonal gammopathy, is characterized by deposits of amorphous light-chain material, mainly in the kidneys but also in various other organs. Here we present the first report of a light-, electron microscopic and immunohistochemical study of the globes of a patient suffering from LCDD secondary to multiple myeloma. Massive deposits of kappa light chains similar to those typically present in the kidneys were found beneath the basement membrane of the ciliary pigment epithelium, on vessels of the ciliary body, within the collagenous zones of Bruch's membrane, and in the innermost part of the choroid. The choriocapillaris in the macular area was partly obstructed by these deposits, and an exudative retinal detachment was present. Whether this detachment was the consequence of disturbed circulation of the choriocapillaris remains speculative.

Corneal Opacity Leading to Multiple Myeloma Diagnosis: A Case Report and Literature Review

Patient: Female, 54

Final Diagnosis: Multiple myeloma

Symptoms: A 9-month history of blurred vision

Medication: Systemic chemotherapy with vincristine • cyclophosphamide • dexamethasone

Clinical Procedure: Multiple myeloma patient presenting with corneal opacity and blurred vision as chief complaint

Specialty: Ophthalmology and Hematology

In vivo confocal microscopic characteristics of crystalline keratopathy in patients with monoclonal gammopathy: report of two cases

In this paper, we report two cases of a 62-year-old patient presented with blurred vision and a 45-year-old male diagnosed with multiple myeloma who was referred from the Department of Oncology. Slit-lamp examination, in vivo confocal microscopy (IVCM), systemic work-up and serum protein electrophoresis were obtained. In both patients, slit-lamp findings revealed bilateral diffuse subepithelial and anterior stromal crystals and IVCM showed highly reflective deposits in the corneal epithelium and stroma. The first patient was eventually diagnosed with monoclonal gammopathy of undetermined significance following bone marrow biopsy and systemic evaluation. Unusual corneal deposits may constitute the first sign of monoclonal gammopathies. IVCM may be helpful in showing the crystalline nature of the corneal deposits and guiding the clinician to the diagnosis of gammopathies. Both ophthalmologists and oncologists should be aware that corneal deposits may herald a life-threatening hematologic disease.

Cloudy corneas as an initial presentation of multiple myeloma

Summary

We report a case of previously unsuspected myeloma, presenting with cornea verticillata due to intracorneal paraprotein deposition.

History

An 85-year-old female presented via her optician with a 4-month history of cloudy vision. She had undergone an uneventful bilateral phacoemulsification surgery 7 years earlier. Extensive spiraling corneal epithelial opacification was noted on slit-lamp examination. On further investigation, she was found to have a previously unsuspected low-grade multiple myeloma. We established the nature of the corneal deposits with corneal epithelial biopsy histopathology and electron microscopy. It is very rare for multiple myeloma to present in this fashion. Ophthalmologists should be aware that such a presentation may rarely be due to systemic multiple myeloma.

Chameleon-like appearance of immunotactoid keratopathy

PURPOSE

To demonstrate 5 different patterns of immunotactoid keratopathy (ITK) in monoclonal gammopathy of undetermined significance (MGUS) that can mimic hereditary and degenerative disorders. First follow-up of 1 female patient was performed.

METHODS

Colored slit-lamp photodocumentation of 6 MGUS light kappa patients with different types of ITK, one patient with a follow-up of 7 years. Systemic and serological examinations of all 6 patients were performed.

RESULTS

The systemic and serological examinations disclosed an MGUS light kappa in all 6 patients. The 7-year follow-up of case 2 showed a reduction of lattice-like opacity to moderate diffuse corneal opacity. Corneal opacity patterns of the 6 patients were as follows: pattern 1, crystalline-like; pattern 2, lattice-like; pattern 3, peripheral granular-like; pattern 4, peripheral band-like; and patterns 5 and 6, peripheral patch-like.

CONCLUSIONS

ITK of MGUS can mimic cystinosis, Schnyder corneal dystrophy (CD), pre-Descemet CD, lattice CD, granular CD, arcus lipoides, lecithin-cholesterol acyltransferase deficiency, gelatinous drop-like CD, and Salzmann nodular degeneration. ITK can be the first symptom of MGUS. An annual internal check of MGUS is recommended because of occurrence of a systemic monoclonal gammopathy in 20% of cases.

Atypical corneal immunoglobulin deposition in a patient with dysproteinemia

PURPOSE

The purpose of this study was to report an unusual pattern of immunoglobulin deposition in the corneas of a patient with dysproteinemia.

METHODS

Clinical examination, slit lamp examination, a deep lamellar corneal biopsy, and serum and aqueous protein electrophoresis were obtained.

RESULTS

Slit lamp evaluation revealed amorphous, cloud-like opacities in the midperiphery at the level of deep stroma and Descemet's membrane. Electron microscopy demonstrated deep lamellar extracellular deposits consistent with immunoglobin. The serum protein electrophoresis revealed a monoclonal IgG kappa band, but the aqueous electrophoresis showed no bands in the gamma region.

CONCLUSION

This case documents a rare pattern of immunoglobulin deposition in the corneas in a patient with gammopathy. Despite its deep corneal distribution, the analysis of the aqueous specimen suggests that the source of the immunoglobulin is through a route other than from the aqueous.

IgG-κ Immunoglobulin Deposits Involving the Predescemetic Region in a Patient With Multiple Myeloma

PURPOSE

To report the clinico-pathologic features of corneal deposits in a patient with multiple myeloma with surgical intervention and follow-up.

DESIGN

Interventional case report.

METHODS

We reviewed the patient's chart and the relevant literature on immunoglobulin corneal deposits and its prognosis.

RESULTS

A 52-year-old man with a history of multiple myeloma underwent penetrating keratoplasty sequentially for decreased vision in both eyes secondary to abnormal corneal deposits. Pathologic examination of the keratectomy specimens, including immunohistochemistry and transmission electron microscopy, revealed IgG-kappa immunoglobulin deposits in the predescemetic region in both corneas. After keratoplasty, he regained excellent vision in both eyes, which was maintained at the end of 18 months of follow-up in both eyes despite early signs of recurrence in the right eye. His systemic condition was well controlled during the period of follow-up.

CONCLUSION

Corneal deposits in multiple myeloma are well described in the literature, but there are few reports regarding the prognosis and visual function after penetrating keratoplasty. Our report shows that when the systemic condition is well controlled, penetrating keratoplasty has an excellent prognosis in these patients.

Immunotactoid keratopathy: a clinicopathologic case report and a review of reports of corneal involvement in systemic paraproteinemias

Corneal deposits in association with paraproteinemias have been well described in the ophthalmic literature. Recent reports in the renal literature have described immunotactoid deposition associated with glomerulopathy-organized microtubular deposits of IgGkappa that measured 32-50 nm in diameter on renal biopsies. We present a case of corneal immunotactoid deposition in the setting of chronic lymphocytic leukemia and review previous reports of corneal deposition in the setting of systemic paraproteinemia, highlighting the etiology, differential diagnosis, prognosis, and treatment of corneal involvement. We propose the use of the term immunotactoid keratopathy to describe corneal IgGkappa deposits appearing as tubular, electron-dense, crystalloid deposits with a central lucent core on electron microscopy and suggest that these patients undergo directed systemic workup to evaluate for potential etiologies of their systemic paraproteinemia. To illustrate the spectrum of paraprotein deposition in the cornea, and to emphasize the importance of ophthalmic evaluation in the setting of systemic paraproteinemias, we include a case of a 44-year-old man with immunoprotein corneal deposition who was subsequently diagnosed with multiple myeloma.

Keratopathy of multiple myeloma masquerading as corneal crystals of ocular cystinosis

We describe a 49-year-old woman in whom ocular cystinosis was diagnosed on the basis of a routine eye examination 12 years previously. Conjunctival biopsy was reported to support the diagnosis. The patient described photophobia for the past 5 years and reported a 2-fold increase in her serum IgG level for the past 12 years. On ophthalmic examination, corneal crystals were evident in the epithelium and superficial stromal layers, rather than throughout the corneal epithelium and the entire stroma as in ocular cystinosis. The patient's serum protein level was elevated at 8.7 g/dL; protein electrophoresis showed an elevated gamma-globulin peak, and the IgG level was twice that of normal at 2820 mg/dL. Bone marrow biopsy confirmed the diagnosis of multiple myeloma. This case illustrates that multiple myeloma can mimic corneal findings of cystinosis.

Annular crystalline keratopathy in association with immunoglobulin therapy for pyoderma gangrenosum

PURPOSE

To report on a patient with a clinical presentation of annular crystalline keratopathy after immunoglobulin therapy for pyoderma gangrenosum.

METHODS

Case report of a 6-year-old boy with biopsy-proven history of pyoderma gangrenosum who had undergone several cycles of systemic immunoglobulin therapy. The literature on ocular manifestations associated with pyoderma gangrenosum was reviewed.

RESULTS

One year after the last cycle, the patient complained of the sudden onset of photophobia. Slit-lamp biomicroscopy revealed bilateral symmetric crystalline deposits in an annular region of the cornea. Because visual acuity was not reduced, specific therapy was not initiated. Symptoms could be reduced by the prescription of medical edged filter lenses.

CONCLUSIONS

Annular crystalline corneal deposits may be associated with immunoglobulin therapy or represent a hitherto unknown ocular complication of pyoderma gangrenosum.

Paraproteinemic crystalloidal keratopathy: an ultrastructural study of two cases, including immunoelectron microscopy

The ultrastructural appearances of corneal crystalloidal deposits are described in two patients with an IgG-kappa paraproteinemia of uncertain pathogenesis. The crystalloids in one patient were overwhelmingly intracellular and were found mainly in stromal keratocytes, but also in basal corneal epithelial cells and the limbal vascular endothelium. Four types of crystalloid or immunoprotein-containing granules were recognizable in this case: 1) fibrillary crystalloids with a curvilinear filamentous substructure; 2) angulated geometric crystalloids that often had a linear filamentous substructure and transverse or oblique periodicity; 3) cordlike crystalloids; and 4) lysosomelike granules with amorphous contents. Immunoelectron microscopy demonstrated that all of these structures labeled for kappa-light chains, and rectangular type 2 crystalloids showed approximately a twofold greater concentration of the colloidal gold probe than the type 1 fibrillary crystalloids. The evidence suggested development of the crystalloids within lysosomes, with a progression from the granules containing amorphous material, through fibrillary crystalloids, to the geometric structures. The circumferential distribution of the corneal deposits, as well as the presence of vascular endothelial crystalloids and reduplication of external laminae around limbal blood vessels, suggests that the crystalloids originated predominantly or entirely from the blood, with transport of immunoprotein across damaged limbal microvasculature. The abnormal vasculature may also have contributed to corneal edema, which in turn may have exacerbated corneal opacification. The crystalloidal deposits in the other case were exclusively extracellular; they were located beneath and between corneal basal epithelial cells, and predominantly as a mantle around individual keratocytes. The crystalloids in this case consisted overwhelmingly of thick-walled tubules about 40 nm in diameter that labeled for both kappa-light chains and gamma chains with the colloidal gold immunoprobe. In addition, lucent vesicles within keratocytes were found only in sections labeled for kappa-light chains and were positive. The factors that might contribute to the formation of corneal crystalloidal deposits in immunoproliferative disorders are discussed, and include: 1) an inherent propensity for crystallization of some immunoglobulins or kappa-light chains, perhaps because of abnormal molecular structure; and 2) local factors in the cornea that might promote deposition and crystallization of immunoprotein, such as temperature, pH, the water content, and extracellular matrix components.