Internal Medicine, Thessaly University School of Medicine, Larisa, Greece
SIR, Lymphadenopathy is not a well described feature of systemic sclerosis (SSc). In this report we describe a patient with SSc who had bilateral hilar adenopathy with eggshell calcification and supraclavicular adenopathy.
A 38-yr-old man presented with diffuse muscle and joint pain, Raynaud's phenomenon in his fingers and toes, oedema in his hands, and fatigue. These symptoms started approximately 1 yr before admission. Past medical history revealed a partially corrected cleft palate. The patient had worked in quartz stonecutting for approximately 1 yr, 5 yr before admission. On examination, his skin was remarkable for thickening involving his fingers, hands, arms, legs, face and torso. There was tenderness of the wrists, metacarpophalangeal joints and knees bilaterally, and mild swelling of his knees. Grip strength was markedly diminished bilaterally. In the right supraclavicular region there was a palpable mass 5 cm in diameter, which was non-adherent, rubbery in consistency and non-tender. Auscultation of the lungs revealed a few fine crackles bilaterally.
The full blood count and basic biochemistry profile were within normal limits except for the erythrocyte sedimentation rate, which was 94 mm/1st h, and C-reactive protein concentration, which was 4.0 mg/ml (upper normal value <0.5 mg/ml). Serum angiotensin-converting enzyme was 2.2 ng/ml, serum calcium 10.0 mg/dl and 24-h urine calcium 262 mg; all were within normal limits. He was positive for antinuclear antibodies (titre 1/320, homogeneous pattern), strongly positive for Scl-70 (200 U; normal values <20 U), and negative for rheumatoid factor.
Plain chest films revealed interstitial infiltrates, notably in the lower lobes bilaterally, and a slight widening of the mediastinum. High-resolution CT (HRCT) scanning of the chest showed micronodular shadowing, mostly in the upper lobes, interstitial fibrosis in the lower lobes and a few traction bronchiectases. There was mild enlargement of the hilar and mediastinal lymph nodes, which had peripheral eggshell-like calcification, and moderate dilation of the oesophagus (Fig. 1). Pulmonary function tests revealed the FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) ratio to be mildly elevated. Diffusion capacity was diminished (46% of predicted). Bronchoalveolar lavage (BAL) showed lymphocytes 21%, macrophages 76%, neutrophils 2% and histiocytes 1%. The CD4/CD8 ratio was 1.19. Two transbronchial lung biopsies 2 months apart were taken from the middle lobe of the lungs, and demonstrated non-specific mononuclear cell infiltration and fibrosis. No granulomas were found. No silica particles were found in BAL or transbronchial biopsies. Biopsy of a supraclavicular lymph node showed fibrosis in interfollicular areas and around blood vessels, and a few epithelioid histiocytes that exhibited calcinosis. Immunohistochemistry of the lymph biopsy revealed mild reactive B-cell hyperplasia.
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Bilateral hilar lymphadenopathy, although not pathognomonic, is characteristic of sarcoidosis. Sarcoidosis is characterized by non-caseating granulomas. An increased CD4/CD8 ratio, especially if >8, is highly suggestive of sarcoidosis.
Hilar adenopathy with eggshell calcification is a common feature of silicosis. Silicosis is the fibrotic reaction of the lung to inhaled free silica (silicon dioxide, SiO2) or its product, crystalline quartz. The major occupations in which exposure occurs include mining and stonecutting. Plain chest X-rays show hilar lymph node enlargement and numerous small pulmonary nodules, which tend to occur first in the upper lobes. The hilar lymph nodes may exhibit eggshell calcification [4].
Silica dust exposure is a well-recognized risk factor for developing SSc [5]. The risk of developing SSc after exposure to silica dust is up to four times greater than that for the general population [6]. Silica-associated SSc appears after a mean of 16.2 yr (range 436 yr) of silica exposure [7, 8]. Sometimes the development of SSc may be a consequence of the intensity rather than the duration of silica exposure [9]. Our patient worked in stonecutting of quartz for approximately 1 yr, 5 yr before admission. However, his partially corrected cleft palate may have contributed to an increased proportion of the inhaled silica dust reaching the alveoli. Silica-associated SSc is clinically and serologically indistinguishable from idiopathic SSc [5, 7, 8]. In the majority of cases (72%), silicosis onset occurs before the onset of SSc [8]. The lungs are almost invariably involved in silica-induced SSc [10], with pulmonary fibrosis in the basal parts. Pathophysiologically, silica can activate macrophages directly in vitro, and this leads to the production of tumour necrosis factor , interleukin (IL) 1 and IL-6 [8]. IL-6 in turn may direct T cells towards the TH2 type, and such T cells are thought to operate in SSc. The co-occurrence of both silicosis and scleroderma is a likely diagnosis in the case presented here.
Conflict of interest
The authors have declared no conflict of interest.
Notes
Correspondence to: L. Sakkas. E-mail: lsakkas{at}med.uth.gr
References