Musculoskeletal ImagingLymphoma
a diverse group of lymphoreticular neoplasms, which includes
non Hodgkins lymphoma,
Hodgkins disease,
Burkitts lymphoma,
mycosis fungoides and giant follicle
lymphoma (
Brill Symmers disease. Generally the lymphomas are divided into two broad categories: Hodgkin's disease and the
malignant lymphomas. Lymphomas may arise either in extraskeletal sites or as a primary process in bone. Lymphomas originating in bone tend to occur in older patients and are seen more frequently in men. Muscle enlargement of muscles is well recognized to occur in lymphomas.
Skeletal abnormalities in non-Hodgkin's lymphoma predominate in the axial skeleton. Although most tumours spread via the haematogenous route, bone invasion from surrounding soft tissues and lymph nodes may also occur. On radiographs the appearance is of multiple osteolytic lesions with motheaten or permeative bone destruction. Adjoining soft tissues may also be involved. Osteosclerosis occurs rarely.
Hodgkin's disease
is a form of
malignant lymphoma with
lymphadenopathy and splenomegaly, anaemia and sometimes bone abnormalities. Bone involvement may occur from haematogenous dissemination or direct spread from contiguous involved
lymph nodes. The bones involved most commonly are those of the
spine and
pelvis and the ribs, femora and sternum. Patients may reveal osteosclerosis or osteolysis; in some cases these two features are present together. An
ivory vertebral body similar to that seen in other lymphomas and
Pagets disease may also be noted.
Burkitt's lymphoma
represents a stem cell
lymphoma occurring predominantly in children, especially in tropical Africa. The facial bones, particularly the maxilla, can be involved to the point of producing facial disfigurement. In addition, patients may develop a soft tissue mass that extends into the buccal cavity or maxillary antrum. Pelvic bones and
tubular bones may also be involved, although less frequently. In these sites,
osteolytic foci penetrate the cortex and lead to periostitis, with a resulting soft tissue mass.
Mycosis fungoides
is an unusual form of
malignant (T cell)
lymphoma with primary involvement of the skin. Cutaneous lesions may be associated with
lymphadenopathy and visceral involvement, but bone marrow involvement is rare. Lesions occur in the appendicular skeleton, leading to cortical destruction, periostitis and soft tissue swelling. Involvement of the peripheral skeleton including the hands may be a helpful clue in the diagnosis of mycosis fungoides. In the leukaemic phase of this disease, termed Szary syndrome, patients exhibit generalized erythroderma, splenomegaly,
lymphadenopathy and leukocytosis.
Giant follicle lymphoma
, a
benign form of
lymphoma leading to enlarged
lymph nodes, may also result in
malignant transformation in some cases. The histologic features of this disease may be seen in all forms of
lymphoma except Burkitt's
tumour. Occasionally
osteolytic lesions occur, especially in the hands and feet. These lesions may be associated with bone expansion and a peculiar lacelike trabecular pattern.
MR imaging is very valuable for analysis of bone marrow involvement in lymphoma. Focal or diffuse regions of low signal intensity on T1-weighted spin-echo MR images and of high signal intensity on T2-weighted spin-echo MR images are typical. Determination of the extent of bone and soft tissue involvement of the spin is also possible with this technique.
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