• Felty syndrome: Triad of
○ Rheumatoid arthritis (RA)
○ Splenomegaly
○ Neutropenia
IMAGING
• Usually severely deforming
RA
○ Erosions
○ Cartilage destruction
○ Joint deformities
• May have other
extraarticular manifestations of RA
○ Rheumatoid nodules
○ Vasculitis
○ Sjögren syndrome
○ Pericarditis
CLINICAL
ISSUES
• Rare process
• Usually Caucasian female
• High titer rheumatoid factor
(RF)
• Often have HLA-DR4 and other
alleles associated with disease severity in RA
• Etiology unknown
○ Neutropenia may result from
splenic sequestration of granulocytes
• Treatment parallels that of
RA
○ Disease-modifying drug
therapy; rituximab (monoclonal anti CD20 antibody) reported effective
○ Arthroplasty, arthrodesis as
needed to regain function
• Consider splenectomy if
○ Splenomegaly is massive
○ Patient suffers recurrent
infections
• Associated large granular
lymphocytic leukemia in 40% of cases
• Most cases of neutropenia in
RA are acquired, not Felty syndrome
○ Related to medications used for RA
Anteroposterior
radiograph shows splenomegaly ,
along with severe erosive disease of the hips, resulting in protrusio . This
is a typical case of Felty syndrome; the patient also had neutropenia. In this
rare syndrome, the arthritic process is usually severe, as in this case.
Anteroposterior radiograph shows severe splenomegaly as outlined by the bowel gas in the splenic flexure. No other abnormality is present, and there is a wide differential based on this image alone.
AP radiograph of the forefoot in the same patient
shows joint space narrowing and erosive change of the 5th metatarsal
head .
AP radiograph of the contralateral foot shows a symmetric
pattern of cartilage narrowing and erosive change at the 5th metatarsophalangeal
joint . The patient proved to have rheumatoid arthritis and neutropenia, as
well as the noted splenomegaly, completing the triad of Felty syndrome. It is
unusual for the RA to appear so mild in a patient with Felty syndrome.