Cutaneous metaplastic synovial cyst in Ehlers-Danlos syndrome.

Classic Ehlers-Danlos syndrome (EDS) is a connective tissue disorder characterized by laxity. The skin, as one of the organs involved, shows hyperextensibility, which makes it prone to trauma. In this context, it would seem logical for cutaneous synovial metaplasia, which is considered a form of repair, to be commonly found in cases of EDS. However, there are only two previously published cases of synovial metaplasia in EDS. We present a third case in a 56-year-old woman with painful redundant skin in both elbows and knees for whom a skin fold of the left elbow was removed to relieve her symptoms. The biopsy showed preservation of the elastic and collagen fibers. The main alteration was the evidence of dermal cystic spaces lined by fibrinoid rests with focal pseudopapillary projections. However, in some zones the cellular lining was preserved, and it was composed of vimentin-positive, fibroblast-like flat, elongated cells, as well as CD68-positive macrophages. No birefringent particles were found in an examination under polarized light.

Intrinsic multipotential mesenchymal stromal cell activity in gelatinous Heberden's nodes in osteoarthritis at clinical presentation.

INTRODUCTION: Gelatinous Heberden's nodes (HNs), also termed synovial cysts, are a common form of generalized osteoarthritis (OA). We sought to determine whether HN cases at clinical presentation contained multipotential stromal cells (MSCs) and to explore whether such cells were more closely related to bone marrow (BM) or synovial fluid (SF) MSCs by transcriptional analysis. METHODS: At clinical presentation, gelatinous material was extracted/extruded from the distal phalangeal joint of OA patients with HNs. From this, plastic adherent cells were culture-expanded for phenotypic and functional characterization and comparison with BM- and SF-MSCs. Mesenchymal related gene expression was studied by using a custom-designed TaqMan Low Density Array to determine transcriptional similarities between different MSC groups and skin fibroblasts. RESULTS: In all cases, HN material produced MSC-like colonies. Adherent cultures displayed an MSC phenotype (CD29(+), CD44(+), CD73(+), CD81(+), and CD90(+) and CD14(-) CD19(-), CD31(-), CD34(-), CD45(-), and HLADR(-)) and exhibited osteogenic, chondrogenic lineage differentiation but weak adipogenesis. Gene cluster analysis showed that HN-MSCs were more closely related to SF- than normal or OA BM-MSCs with significantly higher expression of synovium-related gene markers such as bone morphogenic protein 4 (BMP4), bone morphogenetic protein receptor type 1A (BMPR1A), protein/leucine-rich end leucine-rich repeat protein (PRELP), secreted frizzled-related protein 4 (SFRP4), and tumor necrosis factor alpha-induced protein 6 (TNFAIP6) (P <0.05). CONCLUSIONS: Gelatinous HNs derived from hand OA at clinical presentation contain a population of MSCs that share transcriptional similarities with SF-derived MSCs. Their aberrant entrapment within the synovial cysts may impact on their normal role in joint homeostasis.

Podoplanin and clusterin are reliable markers of nonneoplastic synovium at various sites.

INTRODUCTION: Clusterin (CLU) has been noted to mark synovium adjacent to tenosynovial tumors, and studies suggest that podoplanin (PP) is upregulated in inflammatory arthritis. Characterization of synovial staining with CLU and PP in various nonneoplastic disease states has not been described. METHODS: A microarray was created from paraffin-embedded human synovium, including 19 normal/noninflammatory (10 weight-bearing joints, 8 non-weight-bearing joints), 9 rheumatoid arthritis, 10 synovial cysts, and 3 osteoarthritis and stained with PP (D2-40) and CLU. Staining intensity was graded semiquantitatively (0-3+). RESULTS: PP and CLU stained synovium in 88% and 95% cases, respectively. PP and CLU showed moderate to strong (3+) staining in 26% and 19% of noninflammatory and 44% and 0% of inflammatory synovia, respectively (P < .01). CONCLUSIONS: PP and CLU are reliable markers of human synovium and can confirm its presence in limited specimens. Although CLU was more sensitive, PP may be more useful in the setting of chronic inflammation.

Ganglion of the distal interphalangeal joint (myxoid cyst): therapy by identification and repair of the leak of joint fluid.

BACKGROUND: Digital myxoid cysts are a relatively common pathology in the skin, representing a ganglion of the adjacent distal interphalangeal joint. Success of treatment is largely proportional to the destructiveness of the therapy and postoperative morbidity. We studied an effective, minimally traumatic surgical treatment in which tissue is not removed and morbidity is low. DESIGN: Open, nonrandomized trial of therapy. Methylene blue dye was injected into the distal interphalangeal joint. A skin flap was designed around the cyst and raised to identify the dye-filled communication between joint and cyst. The communication was sutured and the flap was replaced with no tissue excision. SETTING: Two university dermatology departments. PATIENTS: Fifty-four subjects with 47 cysts involving fingers or thumbs and 7 involving toes. Previous therapies in 37 patients had resulted in relapse. MAIN OUTCOME MEASURES: Clinical assessment at 2 and 8 months. RESULTS: We treated 34 women and 20 men (mean age, 60.4 years; range, 45-83 years). Communication between cyst and joint was identified by means of methylene blue injection in 48 patients (89%). At 8 months, 48 patients remained cured with no visible scarring. Of these, nail dystrophy associated with the cyst preoperatively (n = 35) resolved in all but 1 patient (97%). Six patients had relapses (5 within 4 months). Of these, 3 were on the toes. Cure rate on toes was 4 of 7 (57%) and on fingers, 44 of 47 (94%). In 2 patients, pain persisted for 4 months and then resolved. Limitation of joint mobility resolved after 2 months in 1 subject. CONCLUSIONS: Ligature of myxoid cyst origin at the joint capsule is an effective treatment and does not require excision. Myxoid cysts on toes are more likely to relapse than those on fingers.

Unusual facet cyst containing struvite and hydroxyapatite.

This case report describes a patient with severe back pain and radiculopathy. She was found to have a facet cyst within the lumbar spine that appeared to contain calcium on MRI and CT. Upon aspiration the cyst was found to contain calcium ammonium phosphate (struvite) and calcium phosphate (hydroxyapatite). Ammonia production in the presence of urease-producing bacteria is responsible for the production of struvite in the human body. We postulate that there was a prior infection of the facet with urease-producing bacteria, thus accounting for the production of the struvite within the facet cyst.

SPECT using Bremsstrahlung to quantify 90Y uptake in Baker's cysts: its application in radiation synovectomy of the knee.

The use of SPECT with Bremsstrahlung radiation has been investigated in studies on patients undergoing 90Y therapy for persistent synovitis of the knee. In particular, its value in the estimation of 90Y uptake into Baker's cysts was assessed and, to this end, realistic 'knee phantoms' were employed in order to calibrate for cysts of different size. Problems associated with the measurement of the extensive Bremsstrahlung spectrum and the estimation of cyst volume have been discussed. It is shown that, although the apparent volume of a cyst is markedly dependent on the chosen count rate threshold, volumes greater than about 30 ml can be estimated with reasonable accuracy using a threshold of 50%. The uptake of 90Y in cysts, measured on 3 occasions within the first 2 days in 10 patients, showed wide variation (0%-40%) between patients and was poorly related to the size of cysts on arthrograms and to the clinical response to therapy. In these studies, the ability to analyse SPECT slices provided a distinct advantage over planar imaging for discriminating between 90Y uptake in cysts and adjacent sites. Retention of 90Y in the total knee was also widely variable, with losses of 2%-38% observed 2 days after injection which, in general, were not fully accounted for by uptake in liver or lymph nodes. The changing distribution of 90Y colloid in the knee during the first two days, as observed in some patients, might explain part of the discrepancy.

Gas in spinal articulations.

The purpose of this review is to illustrate, some for the first time, a variety of gas collections in lumbar facet joints and intervertebral discs and in the sacroiliac joint.

Cysts of the semilunar cartilage of the knee. A light and electron microscopic study.

The semilunar cartilages of the knee of six cases showing various degrees of mucoid degeneration with cyst formation were studied with the light microscope. Three cases were selected for electron microscopic observation which revealed that some of the cystic spaces filled with mucoid material were lined by synovial cells. Masses of mucinous, alcian bluc positive material (acid mucopolysaccharides) were observed also among degenerated and intact bundles of collagen. It is concluded that the accumulation of acid mucopolysaccharides in meniscial cysts is at least in part a product of secretion of synovial cells. This observation explains the high incidence of recurrence of meniscial cysts after incomplete surgical excision and supports the concept that it is an active rather than a degenerative process.