Non-fibrositic lumbar subcutaneous nodules: prevalence and clinical significance

Lumbar subcutaneous nodules (LSNs) have been associated with fibrositis but are distinct from painful myalgic trigger points and tender points. One hundred and twenty-six adults (53 males and 73 females) were examined for LSNs. LSNs varied in size from a +/- 3 mm 'corn kernel' (15/47) to +/- 5 mm 'pea' (21/47) to +/- 10 mm, 'grape' (11/47), occurred singly (22/47) and in clusters of two to seven uni- and bilaterally. Eight of 47 LSNs overlying the posterior superior iliac spines (PSIS) were tender. The results of a cross-tabular analysis using disease as the independent variable and presence or absence of LSNs as the dependent, found no differences (chi 2 = 1.06, df = 2). LSNs occur near the PSIS in approximately 25% of white adults, are rarely a cause of back pain, and should seldom require biopsy.