[The pressure-sensitive swelling in the knee as a sign for a monoclonal gammopathy of undetermined specificity (MGUS)].
AL amyloidosis (AL-A) is seen in about 6-15 % of patients with multiple myeloma. In contrast, the sporadic occurrence of AL-A is a rarity. The presence of amyloid is often found in the respiratory tract followed by the lung, the eyelids, the skin and the lower urinary tract, while the presence in soft tissues or bone is rather uncommon. We here describe a 71-year-old woman who presented with a pressure-sensitive swelling in the left knee at our hospital. The clinical examination on admission showed a tumourous alteration of the popliteal soft tissues without any signs of neurological deficits. However, the range of motion (ROM) of the left knee was restricted with 0-0-100 degrees for extension and flexion. A dialysis-dependent renal insufficiency, heart insufficiency with the necessity of permanent anticoagulation and glaucoma were noted as pre-existing illnesses. Further diagnostic examinations including ultrasound and magnetic resonance imaging (MRI) of the left knee revealed a solid tumourous structure with a radiological suspicion of pigmented villonodular synovitis. A complete surgical extirpation of the tumourous structure was performed. The further performed diagnostic examinations including histological and immunohistochemical analyses showed evidence of an AL-A tumour. A monocloncal gammopathy of unknown specificity (MGUS) was detected as an origin for the AL-A. This case underscores the necessity of complete extirpation and histological and immunohistochemical analyses of any soft tissue tumour. Possible previously existing rare malignant diseases can be detected only in this way.
Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Chirurgische Klinik und Poliklinik, Bochum.
SourceZeitschrift für Orthopädie und Unfallchirurgie 150:5 2012 Oct pg 499-502
Monoclonal Gammopathy of Undetermined Significance
Pub Type(s)Case Reports