Spinal IgG4-Related Hypertrophic Pachymeningitis with Spinal Cord Compression: Case Report and Literature Review.

BACKGROUND: Back pain is a leading reason for patients to seek medical attention. Although musculoskeletal causes are common, patients can also present with rarer etiologies. CASE DESCRIPTION: A 50-year-old man presented with 2 months of isolated upper back pain initially suspected to be secondary to overuse muscular strain. During the next 3 months, his pain worsened, and he developed lower extremity dysesthesia and subjective weakness, despite normal neurological examination findings. Nonrevealing laboratory workup included normal muscle enzymes, C-reactive protein, urinalysis, and human leukocyte antigen B27. Magnetic resonance imaging revealed a normal brain but a hypointense C7-T5 epidural mass, prompting a neurosurgical recommendation for laminectomy with evacuation of the suspected hematoma. His symptoms fully and promptly resolved after a 5-day course of prednisone 40 mg. When his symptoms recurred within 2 months, he underwent T4-T5 laminectomy with biopsy of a mass confluent with the dura mater. Initial pathological examination revealed fibrotic tissue of unclear etiology with polyclonal lymphoid infiltrate but no malignant cells, vasculitis, or granulomas. After months of recurrent, steroid-responsive symptoms, he presented to the rheumatology clinic. Repeat spinal magnetic resonance imaging demonstrated progression of epidural thickening with suspected spinal cord compression. Previous biopsy samples were then immunostained for IgG4, revealing focally dense IgG4-positive plasma cells, up to 29 cells per high power field, consistent with spinal IgG4-related hypertrophic pachymeningitis. He began rituximab therapy with a prednisone taper and demonstrated symptomatic and neurologic improvement with successful withdrawal from corticosteroids. CONCLUSIONS: To the best of our knowledge, the present case represents the 12th reported case of spinal IgG4-related hypertrophic pachymeningitis. An early diagnosis and treatment could prevent progression to permanent neurological impairment and functional disability.

Joint-specific assessment of swelling and power Doppler in obese rheumatoid arthritis patients.

BACKGROUND: Clinical swollen joint examination of the obese rheumatoid arthritis (RA) patient can be difficult. Musculoskeletal Ultrasound (MSUS) has higher sensitivity than physical examination for swollen joints (SJ). The purpose of this study was to determine the joint-specific association between power Doppler (PDUS) and clinical SJ in RA across body mass index (BMI) categories. METHODS: Cross-sectional clinical and laboratory data were collected on 43 RA patients. PDUS was performed on 9 joints (wrist, metacarpalphalangeal 2-5, proximal interphalgeal 2/3 and metatarsalphalangeal 2/5). DAS28 and clinical disease activity index (CDAI) were calculated. Patients were categorized by BMI: <25, 25-30, and >30. Demographic and clinical characteristics were compared across BMI groups with Kruskal-Wallis test and chi-square tests. Joint-level associations between PDUS and clinically SJ were evaluated with mixed effects logistic regression models. RESULTS: While demographics and clinically-determined disease activity were similar among BMI groups, PDUS scores significantly differed (p = 0.02). Using PDUS activity as the reference standard for synovitis and clinically SJ as the test, the positive predictive value of SJ was significantly lower in higher BMI groups (0.71 in BMI < 25, 0.58 in BMI 25-30 and 0.44 in BMI < 30) (p = 0.02). The logistic model demonstrated that increased BMI category resulted in decreased likelihood of PDUS positivity (OR 0.52, p = 0.03). CONCLUSIONS: This study suggests that in an obese RA patient, a clinically assessed SJ is less likely to represent true synovitis (as measured by PDUS). Disease activity in obese RA patients may be overestimated by CDAI/DAS28 calculations and clinicians when considering change in therapy.

Microscopic polyangiitis with dermatomyositis.

Dermatomyositis is a rare autoimmune disease with a heterogeneous presentation that often has multiple extramuscular manifestations, although it does not typically involve the renal function. A 62-year-old female presented with proximal muscle weakness and rashes, which are classic symptoms of dermatomyositis without creatine kinase (CK) elevation. Initial serologic evaluation revealed a positive p-ANCA, although she did not develop renal failure for several months, at which point renal biopsy findings were consistent with microscopic polyangiitis. The patient was initially treated with cyclophosphamide, maintained with rituximab, and has been in remission for more than 2 years. Dermatomyositis and microscopic polyangiitis are both uncommon diseases, but are concomitantly present in this patient. A positive p-ANCA and development of renal insufficiency should be promptly evaluated in dermatomyositis patients.