Paraneoplastic systemic lupus erythematosus associated with papillary thyroid carcinoma.

A 45-year-old caucasian woman was referred to the authors' tertiary level immune-rheumatology clinic with positive antinuclear antibodies and unexplained fatigue, myalgia, and polyarthralgia with morning stiffness, all present for 4 weeks. Additionally, there was a history of photosensitivity without a discoid or malar rash. The patient recalled recurrent episodes of oral aphthous ulcers and Raynaud's phenomenon in the past few weeks. The patient denied similar episodes in the past, and there was no family history of note. Brain magnetic resonance imaging was normal. Past medical history was unremarkable, with the exception of ®-thalassaemia trait and Hashimoto thyroiditis resulting in hypothyroidism for which levothyroxine supplementation had been started, 6 months before the onset of symptoms. The patient did not complain of headache, dysphagia, dyspnoea, palpitations, fever, weight changes or other constitutional symptoms. On examination, the metacarpophalangeal joints bilaterally and the right wrist were tender and swollen, and Raynaud's phenomenon involving the fingers was present, without acral ulcers. Lung, heart and abdomen were normal. A 1 cm hard nodule, fixed to the thyroid gland, was detected in the right lobe, together with a ipsilateral laterocervical lymph node. Laboratory testing confirmed antinuclear antibodies to be detectable at high titre with a speckled pattern. Anti-double stranded DNA antibodies (anti ds-DNA) were detected at 165.5 UI/ml (normal =0.0-10.0 UI/ml), antibodies to extractable nuclear antigens, centromere, mitochondria, anti Smith (anti Sm) and actin were not detected. A full blood count was normal as were thyroid, hepatic and renal indices. A screen for HIV, hepatotropic virus and mycobacteria was negative and there was no proteinuria. However, a mild complement reduction was evident: C3 71 mg/dl (normal 90-180 mg/dl), C4 7 mg/dl (normal 10-40 mg/dl). A chest radiograph, pulmonary function testing and echocardiography were normal. Capillaroscopy showed subclinical Raynaud's phenomenon with lupus-like microangiopathy. There was no indication of specific organ involvement, so first level screening tests were also performed: chest X-ray, abdominal ultrasound and mammography were negative. Thyroid ultrasound demonstrated a focal hypoechoic area of 11 mm at the subcapsular level in the right lobe, with blurred margins, fine calcification within its content, and perinodular and intranodular arterial doppler signal. In light of the suspected thyroid carcinoma, the patient was referred for surgical thyroidectomy; a papillary carcinoma was diagnosed histologically. In the 6 months after surgery, spontaneous resolution of the oral ulcers, photosensitivity and Raynaud's phenomenon was seen: a second capillaroscopy showed regression of microcirculatory abnormalities. More interestingly, complement levels normalized and antinuclear antibody and anti ds-DNA antibody levels returned to normal (Table 1).