Crystal-storing histiocytosis and crystalline keratopathy caused by monoclonal gammopathy of undetermined significance

Does Systemic Hematological Therapy Influence the Course of Paraproteinemic Keratopathy?

The purpose of this article is to evaluate the course of paraproteinemic keratopathy (PPK) in patients undergoing systemic therapy for the underlying hematological disease. Baseline and follow-up examinations included hematological work-up, best-corrected visual acuity, slit-lamp biomicroscopy, and in vivo confocal laser scanning microscopy (IVCM). We included 22 patients with bilateral PPK (aged 68 ± 10.4 years, 11 males). Ten patients with multiple myeloma (MM) underwent on-label systemic therapy. During follow-up, we observed a regression of corneal opacities in three patients under slit-lamp examination and under IVCM, while PPK remained unchanged in seven patients. In three patients with monoclonal gammopathy of ocular significance (MGOS), systemic therapy was initiated off-label to reduce the serum paraprotein load before penetrating keratoplasty (PKP). These patients showed no signs of PPK recurrence for up to 24 months after PKP. In one patient without systemic therapy, a recurrence in corneal grafts occurred within 12 months of PKP. In eight patients without systemic therapy, PPK remained stable. In conclusion, systemic therapy for MM patients reduced corneal opacity in 30% of treated patients. Furthermore, systemic therapy performed before PKP in patients without conventional systemic therapy indication (MGOS) likely postpones PPK recurrence in the corneal graft.

Ocular complications of plasma cell dyscrasias

Plasma cell dyscrasias are a wide range of severe monoclonal gammopathies caused by pre-malignant or malignant plasma cells that over-secrete an abnormal monoclonal antibody. These disorders are associated with various systemic findings, including ophthalmological disorders. A search of PubMed, EMBASE, Scopus and Cochrane databases was performed in March 2021 to examine evidence pertaining to ocular complications in patients diagnosed with plasma cell dyscrasias. This review outlines the ocular complications associated with smoldering multiple myeloma and monoclonal gammopathy of undetermined significance, plasmacytomas, multiple myeloma, Waldenström's macroglobulinemia, systemic amyloidosis, Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy and Skin changes (POEMS) syndrome, and cryoglobulinemia. Although, the pathological mechanisms are not completely elucidated yet, wide-ranging ocular presentations have been identified over the years, evolving both the anterior and posterior segments of the eye. Moreover, the presenting symptoms also help in early diagnosis in asymptomatic patients. Therefore, it is imperative for the treating ophthalmologist and oncologist to maintain a high clinical suspicion for identifying the ophthalmological signs and diagnosing the underlying disease, preventing its progression through efficacious treatment strategies.

Crystal-Storing Histiocytosis: The Iceberg of More Serious Conditions

Crystal-storing histiocytosis is a rare condition that is histologically characterized by intracellular cytoplasmic crystalline inclusions. It usually presents monoclonal immunoglobulins that deposit within histiocytes, which accumulate and affect different organs of the human body and are commonly associated with lymphoproliferative conditions, especially those with plasmacytic differentiation. The prognosis of this condition is variable and related to the underlying clinical disease. In this review article, we aim to describe and discuss the clinical and pathological characteristics of crystal-storing histiocytosis based on the available literature and to provide a thorough differential diagnosis.

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.

Localized ocular crystal-storing histiocytosis and associated lymphoma - Report of two cases and review of literature

Purpose

Observations

Conclusion and Importance

Solitary Extramedullary Plasmacytoma of the Lacrimal Sac With Associated Crystal-Storing Histiocytosis

PURPOSE

To report a rare case of crystal-storing histiocytosis associated with solitary extramedullary plasmacytoma of the lacrimal sac and to review literature on the 2 entities to summarize important diagnostic, management, and prognostic considerations.

METHODS

A case report of the ophthalmologic presentation, pathology workup, and oncologic management is presented. Literature search with focus on lesions occurring in ophthalmic sites and management guidelines from expert panels and working groups.

RESULTS

Crystal-storing histiocytosis associated with solitary extramedullary plasmacytoma arose within the lacrimal sac of a previously healthy middle-aged woman and presented as a painless nodule with epiphora. The biopsy tissue showed sheets of crystal-filled histiocytes, interspersed with monoclonal plasma cells and rarely demonstrated plasma cell phagocytosis. Imaging and laboratory studies confirmed the localized nature.

CONCLUSIONS

Crystal-storing histiocytosis is an uncommon entity in which crystals, most commonly arising from altered immunoglobulins, aggregate within histiocytes and form symptomatic mass lesions. It has been reported in ophthalmic regions in patients with a concurrent lymphoproliferative or plasma cell disorder and can rarely predate a malignancy. The current case is notable because crystal-storing histiocytosis occurs with a localized process, solitary extramedullary plasmacytoma, and presents in an unusual site, the lacrimal sac. Tissue biopsy with multimodal pathological evaluation is necessary to make the diagnosis. Ophthalmologists should recognize that crystal-storing histiocytosis is commonly associated with a hematologic malignancy and, when appropriate, refer the patient for oncologic management. Surveillance may be indicated in cases with no established etiology. Solitary extramedullary plasmacytoma should also be monitored, as a proportion of cases progress to multiple myeloma.

Orbital Crystal-Storing Histiocytosis: A Clinicopathologic Study of 4 Cases

The authors report the clinicopathological features of crystal-storing histiocytosis (CSH) that involved the orbit and conjunctiva and review published cases of CSH. Cases of histologically proven CSH were identified from archives at the Institute of Ophthalmology, London, and a retrospective review of clinical details and pathology was performed for cases between 1997 and 2017. Four cases of CSH were identified: 1 might have arisen from an inflammatory reaction to a silicone retinal buckle and 3 others occurred with localized B-cell lymphomas. Two patients presented with a conjunctival mass, and 2 had an orbital mass causing proptosis and hypoglobus. One case was associated with amyloid deposition and another had an earlier diagnosis of IgG4-related disease. In the patient without underlying lymphoma, the condition settled with removal of the explant and orbital mass, and the 3 with lymphoma underwent orbital radiotherapy with cessation of disease progression. All patients retained good vision. Ocular CSH is rare, can present in several ways, and should prompt investigation for an underlying lymphoproliferative disorder.

Immunoglobulin-Storing Histiocytosis: A Case Based Systemic Review

Crystal-storing histiocytosis (CSH) is a rare event in disorders associated with monoclonal gammopathy and is mostly associated with the accumulation of immunoglobulins (Igs) in the cytoplasm of histiocytes. In this article, we present a case of a 75-year-old female with IgG kappa monoclonal gammopathy of undetermined significance (MGUS) and signs of a non-crystallized version of immunoglobulin-storing histiocytosis (IgSH) in a vertebra corpus. Furthermore, we performed a literature review based on all cases of storing histiocytosis identified by literature search between 1987 and 2020 and identified 140 cases in total. The median age at diagnosis was 60 years (range 18–91), with an equal sex distribution (51% men). The majority of the patients had an underlying neoplastic B-cell disorder, most often multiple myeloma (MM), MGUS, or lymphoplasmacytic lymphoma (LPL). The main affected organ systems or tissue sites were bone (n = 52), followed by head and neck (n = 31), kidney (n = 23), lung (n = 20), and gastrointestinal (GI)-tract (n = 18). IgG was the main immunoglobulin class involved, and most cases were associated with kappa light chain expression. We conclude that IgSH is a rare disease entity but should be considered with unusual findings in several organ systems associated with monoclonal gammopathy, especially with kappa light chain expression.

The evaluation of monoclonal gammopathy of renal significance: a consensus report of the International Kidney and Monoclonal Gammopathy Research Group

The term monoclonal gammopathy of renal significance (MGRS) was introduced by the International Kidney and Monoclonal Gammopathy Research Group (IKMG) in 2012. The IKMG met in April 2017 to refine the definition of MGRS and to update the diagnostic criteria for MGRS-related diseases. Accordingly, in this Expert Consensus Document, the IKMG redefines MGRS as a clonal proliferative disorder that produces a nephrotoxic monoclonal immunoglobulin and does not meet previously defined haematological criteria for treatment of a specific malignancy. The diagnosis of MGRS-related disease is established by kidney biopsy and immunofluorescence studies to identify the monotypic immunoglobulin deposits (although these deposits are minimal in patients with either C3 glomerulopathy or thrombotic microangiopathy). Accordingly, the IKMG recommends a kidney biopsy in patients suspected of having MGRS to maximize the chance of correct diagnosis. Serum and urine protein electrophoresis and immunofixation, as well as analyses of serum free light chains, should also be performed to identify the monoclonal immunoglobulin, which helps to establish the diagnosis of MGRS and might also be useful for assessing responses to treatment. Finally, bone marrow aspiration and biopsy should be conducted to identify the lymphoproliferative clone. Flow cytometry can be helpful in identifying small clones. Additional genetic tests and fluorescent in situ hybridization studies are helpful for clonal identification and for generating treatment recommendations. Treatment of MGRS was not addressed at the 2017 IKMG meeting; consequently, this Expert Consensus Document does not include any recommendations for the treatment of patients with MGRS.

This Expert Consensus Document from the International Kidney and Monoclonal Gammopathy Research Group includes an updated definition of monoclonal gammopathy of renal significance (MGRS) and recommendations for the use of kidney biopsy and other modalities for evaluating suspected MGRS

Maculopathy in Patients with Monoclonal Gammopathy of Undetermined Significance

PURPOSE

To describe clinical findings, laboratory values, and treatment response of patients with monoclonal gammopathy of undetermined significance (MGUS) demonstrating neurosensory macular detachment.

DESIGN

Retrospective case series.

PARTICIPANTS

Seven eyes of 4 patients (3 men and 1 woman; age range, 60-81 years) with neurosensory macular detachment, treatment-resistant submacular fluid, and vitelliform material.

METHODS

We retrospectively reviewed the medical and ocular histories, ocular examination findings, retinal imaging, ocular disease course, and laboratory findings in 4 patients with submacular fluid associated with MGUS.

MAIN OUTCOME MEASURES

Description of the macular findings and treatment courses of 4 patients diagnosed with MGUS maculopathy.

RESULTS

Seven eyes of 4 patients demonstrated neurosensory macular detachment with treatment-resistant submacular fluid and vitelliform material. No eyes demonstrated signs of significant hyperviscosity retinopathy. Fluorescein angiography showed no definite leakage in any involved eye. Laboratory evaluation revealed immunoglobulin G MGUS in all 4 patients. All 4 patients were resistant to treatments aimed at resolving the subretinal fluid, including some combination of anti-vascular endothelial growth factor injections, photodynamic therapy, topical dorzolamide, oral dosing of eplerenone or acetazolamide, or some combination thereof. In 3 patients, MGUS underwent malignant transformation 24 to 144 months after diagnosis, in 1 patient to lymphoplasmacytic lymphoma and in 2 patients to multiple myeloma. The fourth patient showed no evidence of malignancy 8 years after diagnosis.

CONCLUSIONS

Submacular fluid without fluorescein leakage and unresponsive to conventional treatment may suggest an underlying immunoproliferative disorder that we have termed monoclonal gammopathy of macular significance. Given the propensity for monoclonal gammopathy of macular significance to transform into malignant disease in our series, serum protein analysis should be considered in patients with neurosensory macular detachment not attributable to known causes.

Prevention Is the Best Treatment: The Case for Understanding the Transition from Monoclonal Gammopathy of Undetermined Significance to Myeloma

Multiple myeloma is an invariably fatal cancer of plasma cells. Despite tremendous advances in treatment, this malignancy remains incurable in most individuals. We postulate that strategies aimed at prevention have the potential to be more effective in preventing myeloma-related death than additional pharmaceutical strategies aimed at treating advanced disease. Here, we present a rationale for the development of prevention therapy and highlight potential target areas of study.

Non-neoplastic histiocytic and dendritic cell disorders in lymph nodes

Benign and malignant proliferations of histiocytes and dendritic cells may be encountered in lymph nodes. Reactive histiocytic and dendritic cell infiltrates occur in response to diverse stimuli and in addition to causing lymphadenopathy, may be present unexpectedly in lymph nodes excised for other indications. This review summarizes the pathogenesis and histopathological features of the various non-neoplastic histiocytic and dendritic cell infiltrates that can occur in lymph nodes.

Monoclonal gammopathy: The good, the bad and the ugly

Monoclonal gammopathy of undetermined significance (MGUS) is a condition characterized by the presence of a monoclonal gammopathy (MG) in which the clonal mass has not reached a predefined state in which the condition is considered malignant. It is a precursor to conditions such as multiple myeloma or lymphoma at a rate of ~1%/year. Thus, from a hematologic standpoint, MGUS is a fairly benign condition. However, it is now recognized that organ damage resulting from just the MG without the need MM or lymphoma can occur. One of the most recognized is nephropathy secondary to monoclonal gammopathy of renal significance (MGRS). Other well-recognized conditions include neuropathies, oculopathies and dermopathies. Some conditions such as autoimmune diseases and coagulopathies are less common and recognized. Finally, systemic involvement of multiple organs is well described in several entities. In all of these conditions, the role of the MG is no longer insignificant. Thus, the term MGUS should be avoided when describing these entities.

Unusual Manifestations of Monoclonal Gammopathy: I. Ocular Disease

Essential monoclonal gammopathy is usually an asymptomatic condition, the characteristics of which have been defined over approximately 70 years of study. It has a known population-attributable risk of undergoing clonal evolution to a progressive, symptomatic B-cell neoplasm. In a very small fraction of patients, the monoclonal immunoglobulin has biophysical characteristics that can lead to tissue deposition syndrome (e.g. Fanconi renal syndrome) or, by chance, have characteristics of an autoantibody that may inactivate critical proteins (e.g. acquired von Willebrand disease). In this report, we describe the very uncommon forms of ocular injury that may accompany essential monoclonal gammopathy, which include crystalline keratopathy, crystal-storing histiocytosis, hypercupremic keratopathy, and maculopathy. The first three syndromes result from uncommon physicochemical alterations of the monoclonal immunoglobulin that favor crystallization or exaggerated copper binding. The last-mentioned syndrome is of uncertain pathogenesis. These syndromes may result in decreased visual acuity. These ocular findings may lead, also, to the diagnosis of monoclonal gammopathy.

Crystal-storing histiocytosis masquerading ocular adnexal lymphoma: a case report and review of literature

A case of crystal-storing histiocytosis (CSH) associated with mucosa-associated lymphoid tissue (MALT) lymphoma of orbit is reported. The patient was a 53-year-old man who presented with an 8-year history of a slowly enlarging tumor in his right orbit. Histopathologic examination revealed that the tumor was composed predominantly of sheets of spindle-shaped cells resembling striated muscle cells and scattered aggregates of atypical lymphoid cells, showing prominent plasmacytoid differentiation. Immunohistochemical analysis demonstrated that the spindle-shaped cells were CD68-positive histiocytes containing abundant crystals in their cytoplasm, consistent with the diagnosis of CSH. The aggregates of atypical lymphoid cells were diagnosed as MALT lymphoma based on their immunophenotype. Although CSH is a well-recognized manifestation in lymphoproliferative disorders, CSH complicated by MALT type of ocular adnexal lymphoma has rarely been reported. Given the rarity of this, every case presenting with such crystal-storing histiocytes warrants a thorough search for a hidden lymphoid dyscrasia.

Retinal pigment epithelial detachments and tears, and progressive retinal degeneration in light chain deposition disease

BACKGROUND/PURPOSE

Light-chain deposition disease (LCDD) is a rare condition characterised by deposition of monoclonal immunoglobulin light chains (LCs) in tissues, resulting in varying degrees of organ dysfunction. This study reports the characteristic clinical ocular findings seen in advanced LCDD upon development of ocular fundus changes. This is the first report to describe this entity in vivo in a series of patients.

METHODS

A case series of ocular fundus changes in three patients with kidney biopsy-proven LCDD. All patients underwent best corrected visual acuity (BCVA) exam, perimetry, colour fundus photography and fluorescein angiography; two patients underwent indocyanine green angiography, optical coherence tomography, ultrasound and electroretinography; and one patient underwent fundus autofluorescence.

RESULTS

Three patients, 53-60 years old at initial presentation, were studied. All three presented with night blindness, poor dark adaptation, metamorphopsia and visual loss. Examination revealed serous and serohaemorrhagic detachments, multiple retinal pigment epithelial (RPE) tears, diffuse RPE degeneration and progressive fibrotic changes. Neither choroidal neovascularisation nor other vascular abnormalities were present. Final best corrected visual acuity (BCVA) ranged from 20/40 to 20/300.

CONCLUSIONS

Progressive LC deposition in the fundus seems to damage RPE pump function with flow disturbance between choroid and retina. This pathogenesis can explain the evolution to RPE detachments and subsequent rips and progressive retinal malfunction.

Complete remission of monoclonal gammopathy with ocular and periorbital crystal storing histiocytosis and Fanconi syndrome

A 62-year-old woman presented with crystalline keratopathy, crystal-storing histiocytosis, Fanconi syndrome, and a serum monoclonal IgG-κ and urinary κ light chain. Histology and electron microscopy studies revealed the presence of crystals within macrophages in multiple eye sites, in the kidney and in the bone marrow. The variable domain of the pathogenic κ light chain related to the Vk1-39 gene that was also involved in most previously reported cases of Fanconi syndrome. Owing to the severity of the damage to the eye and a potentially poor kidney prognosis, the patient underwent autologous stem cell transplantation. After 18 months follow-up, she is in complete hematological, ophthalmological, and renal remission.

Crystal-storing histiocytosis: report of a case, review of the literature (80 cases) and a proposed classification

We report a case of crystal storing histiocytosis (CSH) of the upper lip and cheek in a 51-year-old woman and review the clinicopathologic features of 80 cases in the literature. These occurred in 41 men and 39 women with a respective mean age of 59 and 61 years (range 17-81 years). Forty-six patients (58%) had localized CSH, and, of these, 16 (35%) occurred in the head and neck, with the most common site being the eye/orbit. The remaining 34 patients (42%) had generalized CSH primarily involving bone marrow, liver, lymph nodes, spleen and/or kidney. Regardless of whether the CSH was localized or generalized, the vast majority of patients (90%) had an underlying lymphoproliferative or plasma cell disorder, especially multiple myeloma, lymphoplasmacytic lymphoma, or monoclonal gammopathy of undetermined significance. In 7 cases (8.8%), the CSH was associated with a variety of benign disorders, often with an inflammatory background, and no evidence of a clonal lymphoproliferative or plasma cell disorder. Treatment and prognosis varied according to the underlying disease. A classification of CSH based on etiology and/or associated disease and chemical composition of the crystal is proposed, rare non-immunoglobulin variants of CSH are discussed, and a differential diagnosis of other potentially confusing lesions is provided.