Statistics from Altmetric.com
A 74 year old man presented with a foreign body sensation in the right eye superimposed on a slowly growing enlarging lump in the right eyelid. He had no history of recurrent infections, bleeding, weight loss, or night sweats. His only other symptom was chronic backache secondary to osteoarthritis. Past medical history included cataract extraction from the right eye 4 years previously and excision of a basal cell carcinoma from the right pinna 5 years previously. Examination revealed a large firm lesion in the right upper eyelid with no palpable lymph nodes. The clinical diagnosis was of a chalazion.
The lesion was removed surgically and histopathology (Fig 1) revealed an incompletely excised extramedullary plasmacytoma with a high proliferative index and amyloid change. Immunocytochemistry was positive for IgG kappa light chains. Further investigations including full blood count, liver function tests including lactate dehydrogenase (LDH), protein electrophoresis, skeletal survey, and bone marrow aspiration were normal with no evidence of multiple myeloma.
The whole of the upper eyelid was treated with radiotherapy using a customised lead cutout with internal shielding of the eye (Fig 2); 120 kV x rays were used giving a dose of 30 Gy in 10 fractions over 2 weeks.
On follow up (at 2 years) there has been no evidence of local recurrence or the development of myeloma, and lacrimation in the eye appears normal.
Solitary plasmacytomas are rare tumours. They are classified as either solitary plasmacytomas of bone (SPB) or extramedullary plasmacytomas (EMP) of soft tissue. The majority of EMPs (about 80%) involve the upper air passages of the head and are thought to arise in the submucosa, where plasma cells are numerous.3,4 Other sites include lymph nodes, spleen, skin and subcutaneous tissues, gastrointestinal tract, thyroid, and testes.
There is a relation between solitary plasmacytomas and subsequent development of multiple myeloma. About 44–69% of patients with a solitary bone plasmacytoma will develop multiple myeloma within a median time of 3 years.5 Although EMPs recur in almost 50% of cases, this is usually in bone but unlike multiple myeloma it remains circumscribed within the bone with no predilection for the axial skeleton. However, progression to myeloma does occur though at a lower rate than for SPB. Alexiou et al4 reported a rate of progression to myeloma for both upper aerodigestive tract and non-aerodigestive tract extramedullary soft tissue plasmacytomas of 16.1% and 14.6% respectively. As no predictors of progression have been identified patients probably need indefinite follow up.
Eye abnormalities such as cysts of the ciliary body and vascular lesions have been described in multiple myeloma but primary plasmacytoma involving the eye is rare. Nineteen cases affecting the orbit have been described in the literature but this is only the fourth case of a primary plasmacytoma arising from the eyelid that has been reported. Most of the earlier reports of the plasmacytomas arising in the eye are not true plasmacytomas and are in fact granulomas due to chronic inflammation.7 Usual symptoms are progressive painless swelling of the eyelid, proptosis, and diplopia. They can occur at any age but the mean age of onset is in the sixth to seventh decade. The youngest reported case was that of an 11 year old who had plasmacytoma of the orbit.8
Of the three previously reported cases, all were treated with surgical excision.7,9,10 Their immunocytochemistry was IgG lambda chain, kappa light chain, and IgG lambda chain respectively. Our case is similar but was treated successfully with radiotherapy after incomplete excision.
Solitary extramedullary plasmacytomas can be controlled with radiotherapy alone. Response rates with radiotherapy are as high as 94% and 93% for SPB and EMP respectively.11 The optimal dose of radiotherapy has not been defined, though it appears that a dose of at least 30 Gy is required. Many centres use doses of between 40–50 Gy.3 The extent of radiotherapy portals is also a subject of debate with many recommending inclusion of regional lymph nodes if possible. The median survival of patients with EMP treated with radiotherapy was 8.5 years in one study with most patients dying of causes unrelated to their EMP.12
Surgery is also an option, with Alexiou et al4 reporting a lower rate of progression to myeloma for those treated by surgery (6.3%) compared with those treated with radiation (17.5%). The conversion rate for patients treated with both modalities was 13.5%. These results may reflect differences in the size of lesions, with small extramedullary plasmacytomas in easily accessible sites being amenable to surgical excision.
Chemotherapy is used for those patients who progress to multiple myeloma.