To the Editor,
Primary bone lymphomas (PBLs) [1,2] and ocular adnexal (OA) lymphomas [3,4] are rare
types of extranodal lymphomas. Coexistence of these two rare entities without lymph
node infiltration has not been reported previously.
A 55-year-old man presented with left hip pain without a history of trauma. His medical
history and physical examination did not reveal any remarkable findings. The X-ray
radiographs of the pelvis and left hip showed multiple lytic lesions. Body 18fluorodeoxyglucose
positron emission tomography/computed tomography (18F-FDG PET/CT) demonstrated multiple
osteolytic bone lesions in the left zygomatic bone, vertebral column, bilateral iliac
bones, left caput femoris, and trochanter major of the femur with increased 18F-FDG
uptake (SUVmax: 31) (Figure 1a). Tru-Cut biopsy of the caput femoris showed atypical
lymphoid cells that were pancreatin (-), s-100 (-), CD138 (+), CD30 (-), CD20 (+),
CD3 (-), CD5 (-), CD10 (-), bcl-6 (+), and MUM-1 (+), consistent with diffuse large
B-cell lymphoma. Laboratory data were as follows: erythrocyte sedimentation rate,
37 mm/h; lactate dehydrogenase level, 405 U/L; hemoglobin, 12 g/dL; white blood cell
count, 6.74x109/L; platelet count, 250x109/L; normal liver and renal function tests.
Bone marrow aspirate and core biopsy were normal. A rituximab, cyclophosphamide, doxorubicine,
vincristine, and prednisolone (R-CHOP) regimen was planned. However, prior to the
first chemotherapy day, the patient was admitted with swelling of the eyelids, exophthalmos,
proptosis, and vision loss in his left eye that developed progressively over 3 days.
Magnetic resonance imaging (MRI), which was performed two months after the initial
18F-FDG PET/CT, showed an orbital mass with diameters of 36x21x38 mm eroding the superior
wall of the orbita and adjacent soft tissue (Figure 1b). After the detection of orbital
involvement, investigations for central nervous system (CNS) involvement were negative.
Chemotherapy treatment was commenced immediately without doing a biopsy because of
the patient’s vision loss. After 4 cycles of R-CHOP chemotherapy, the patient’s left
hip pain, left eye swelling, exophthalmos, and proptosis resolved completely, but
his vision did not improve. Control 18F-FDG PET/CT showed marked regression of bone
lesions with decreased 18F-FDG uptake (SUVmax: 4.6). Orbital MRI also showed that
the mass had regressed to 14x12 mm in size. After obtaining this response, 2 cycles
of R-CHOP, radiotherapy to the left orbita, and two cycles of high-dose methotrexate
for CNS prophylaxis were planned.
Considering the extensive lytic bone lesions and recent emergence of the OA tumor,
the primary site of the disease must have been the bones in the presented case. Thus,
the diagnosis can be categorized as PBL with OA involvement. An orbital mass was detected
two months after diagnosis by means of MRI, but not by 18F-FDG PET/CT performed at
diagnosis. It would be speculative to claim that such a large mass had arisen in a
two month period. Taking into account that MRI is the gold standard imaging technique
in evaluation of OA tumors [3], the orbital mass, which was probably small at the
beginning, could not have been noticed on 18F-FDG PET/CT. This case emphasizes that
a high suspicion index of OA involvement in PBL cases with any symptoms regarding
the eyes and prompt assessment of the patients with MRI might prevent undesirable
consequences.
Ethics
Ethics Committee Approval: Not applicable; Informed Consent: Not applicable.