Localized Myositis Research Articles

Local myositis ossificans of the hand: a case report and a literature review

Myositis ossificans occurs extremely rare in the wrist and hand. Its clinical manifestations and prognosis differ significantly in comparison to the classical localizations on the thigh or shoulder. It is difficult to diagnose this kind of disease during the early stages of the pathological process. The article presents a clinical case of successful treatment of a patient with myositis ossificans of the lumbricals of the hand. Myositis ossificans in our case is shown not just through local symptoms, but also by clinical neuropathy in the median nerve. A review of the available literature on this topic over the past 40 years is presented.

P152 A rare case of necrotising vasculitis presenting with calf swelling in a 15-year-old female

Abstract Background/Aims We present the case of MF, a 15-year-old female who presented to the paediatric clinic with swelling and pain affecting her right calf. She was previously fit and well. Initial imaging was suggestive of localised myositis but a subsequent muscle biopsy was in keeping with necrotising vasculitis. Methods In May 2021, MF presented to a general paediatric clinic with a 6-week history of right lateral calf pain and swelling to the lateral border of the right proximal fibula. She was systemically well. Blood tests and an x-ray were normal. An ultrasound scan of the right calf showed fusiform thickening of the peroneus longus muscle proximally. There was no discrete mass. The appearance was thought to be an inflammatory process such as myositis. An MRI scan was advised. Over the course of the next few weeks, the swelling and pain to the right calf progressed and she was unable to fully weight bear. Repeat blood tests were normal except CRP 11. CK was normal. At the end of June, an MRI scan of the right lower leg showed significant swelling and oedema along the length of the peroneus longus musculature as demonstrated on ultrasound. Florid oedema extended to involve the soleus and to a lesser extent the lateral head of gastrocnemius. There was thickening and oedema through the subcutaneous fat circumferentially compared to the left side (see images). The appearances were thought to be consistent with myositis but an inflammatory malignancy could not be fully excluded and an opinion from the Birmingham team was recommended. The Birmingham MDT advised that malignancy was unlikely but a CT scan was recommended. The CT scan confirmed the MRI findings (see image). Results MF's symptoms progressed rapidly over a short period of time with diffuse swelling of the right lower limb with associated pain and numbness. She also developed purpuric lesions around the ankle (see photos). The CRP increased to 59 and then 123. CK remained normal. Local rheumatology opinion was sought once malignancy had been excluded. The initial impression was of a focal myositis but a muscle biopsy was requested urgently. IV steroids were administered followed by high dose oral prednisolone as a reducing course. The symptoms improved rapidly. The subsequent biopsy showed a florid necrotising vasculitis affecting the small-medium arterial vessels. There was no evidence of myositis (see image). ANCA was negative and CT renal and abdominal angiogram was normal. Nerve conduction studies showed a very severe sensory lesion of the right sural nerve, which explained the persistent numbness. Mycophenolate mofetil was added and clinical improvement is ongoing. Conclusion We present a rare case of localised vasculitis in the right calf. A literature review indicates this is the first case presented in an adolescent. Disclosure S.C. Earl: None. J. Smith: None. A. Ramanan: Grants/research support; Abbvie.

NCMP-18. FIXED PTOSIS AS A SYMPTOM OF MYOSITIS SECONDARY TO CHECKPOINT INHIBITION

Abstract BACKGROUND A growing number of patients with cancer receive checkpoint inhibitor (CPI) based immunotherapy. Peripheral nervous system toxicities including myositis, myasthenia gravis and inflammatory neuropathy are distinct from their non immunotherapy-related equivalents, with unique clinical presentations and therapeutic considerations. METHODS Patients with CPI myositis and non-fatigable ptosis were identified, and clinical data was retrospectively extracted from the electronic medical record in compliance with MD Anderson Cancer Center Institutional Review Board guidelines. RESULTS 14 patients were identified. Average maximum creatine kinase (CK) was 3571 U/L (range 20-19,794). 9 patients had electromyography and nerve conduction studies documented in our system; all had electrodiagnostic evidence of myopathy and two had evidence of concomitant myasthenia gravis by electrodecrement. Two muscle biopsies revealed myositis with inflammatory T-cell infiltrate. 6 had positive anti-striated muscle antibody titers, 9/14 had concomitant myocarditis, 2 had hepatitis, 2 had pneumonitis and 1 had thyroiditis. All received high dose steroids, 11 received plasma exchange, 4 received rituximab, 4 received tacrolimus and 2 received tocilizumab. 7/14 patients died (50%). Mean time from initial neurology consultation for symptoms to death was 6.46 months (range .3-24). 5 patients had documented clinical stabilization or mild improvement on post-discharge follow-up. CONCLUSIONS While ptosis in patients receiving CPI can initially suggest myasthenia gravis, in patients with rapid onset and ultimately fixed deficits there should be a high index of suspicion for immunotherapy related restricted localized myositis. Myositis may coincide with other toxicities, such as myocarditis and pneumonitis, and can be fatal despite aggressive treatment. Deficits persist on post-discharge follow-up, suggesting protracted recovery for patients who survive.

Injury and subsequent regeneration of muscles for activation of local innate immunity to facilitate the development and relapse of autoimmune myositis in C57BL/6 mice.

To determine whether injury and regeneration of the skeletal muscles induce an inflammatory milieu that facilitates the development and relapse of autoimmune myositis. The quadriceps of C57BL/6 mice were injured with bupivacaine hydrochloride (BPVC) and evaluated histologically. Macrophages and regenerating myofibers in the treated muscles and differentiating C2C12 myotubes were examined for cytokine expression. Mice were immunized with C protein fragments at the base of the tail and in the right hind footpads (day 0) to evoke systemic anti-C protein immunity and to induce local myositis in the right hind limbs. The contralateral quadriceps muscles were injured with BPVC or phosphate buffered saline (PBS) on day 7 or after spontaneous regression of myositis (day 42). The quadriceps muscle in nonimmunized mice was injured with BPVC on day 7. The muscles were examined histologically 14 days after treatment. The BPVC-injured muscles had macrophage infiltration most abundantly at 3 days after the injection, with emergence of regenerating fibers from day 5. The macrophages expressed inflammatory cytokines, including tumor necrosis factor α, interleukin-1β, and CCL2. Regenerating myofibers and C2C12 myotubes also expressed the cytokines. The BPVC-injected muscles from nonimmunized mice had regenerating myofibers with resolved cell infiltration 14 days after treatment. In mice preimmunized with C protein fragments, the muscles injected with BPVC on day 7 as well as on day 42, but not those injected with PBS, had myositis accompanied by CD8+ T cell infiltration. Injury and regeneration could set up an inflammatory milieu in the muscles and facilitate the development and relapse of autoimmune myositis.

A71: Localized Myositis as a Manifestation of Systemic‐Onset Juvenile Idiopathic Arthritis: A Case Series From a Tertiary‐Care Hospital

Background/Purpose:Localized myositis is rarely reported in patients with systemic‐onset JIA (sJIA), despite common symptoms of myalgia. We describe sJIA patients with the manifestation of localized myositis.Methods:We reviewed the charts of 6 pediatric patients with sJIA who developed localized myositis during their disease course.Results:The age at presentation with myositis ranged from 5 to 19 years. 4 were males and 2 were females. Races included Caucasian (4), Caucasian/Mayan (1), and African‐American (1). Three patients had localized myositis with initial presentation of sJIA, and 3 patients developed localized myositis during disease flares. For the disease flare group, the time from diagnosis of sJIA until development of myositis ranged from 3 to 6 years, and 2 of 3 patients were on immunosuppressive agents: methotrexate (MTX) (1), anakinra and MTX (1). All 6 patients complained of localized swelling and pain in a localized muscle group. Accompanying symptoms included arthralgia, arthritis, fever and rash. Three patients had localized erythema of the skin overlying myositis areas on exam. Sites of myositis included unilateral biceps (3), bilateral biceps (1), quadriceps (1), and flexor pollicis longus and flexor digitorum superficialis and profundus (1). All patients had at least one muscle enzyme obtained, and all were normal. Five patients had imaging studies demonstrating evidence of myositis: 2 by ultrasound, 2 by ultrasound and MRI, and 1 by MRI. All 6 patients had laboratory evidence of systemic inflammation, including elevated ESR (41–172 mm/hr) and CRP (54–269 mg/L). Four patients had thrombocytosis (462,000–834,000/μL). Two patients transferred care to another hospital, thus we had no information on follow‐up. The remaining 4 patients responded well to prednisone, with resolution of their symptoms within 4 weeks. One patient underwent incision and drainage for a fluid collection and myositis of biceps muscle. He was initially treated with antibiotics and started on anakinra after negative cultures. Duration of follow‐up since onset of myositis was 6–14 months, and no patients had recurrent myositis. The current treatment of the 4 patients includes infliximab (1), MTX (1), canakinumab and leflunomide (1), and canakinumab and MTX (1).Conclusion:Localized myositis is a rare extraarticular manifestation of sJIA and can present either as an initial manifestation or during a disease flare. Patients usually present with unilateral or bilateral localized swelling, overlying warmth and erythema, and pain of one muscle group, most commonly the biceps in our series of patients. Our subjects' muscle enzymes were normal, likely secondary to the focal nature of muscle inflammation. Imaging studies are helpful in establishing the diagnosis. To our knowledge, this study represents the largest series to date of sJIA patients with localized myositis.

측두근과 외측 익돌근에서 발생된 국한성 화골성 근염 : 개구제한을 주소로 내원한 환자의 증례보고

국한성 화골성 근염은 근육내에 섬유조직과 이소성 골이 형성되는 질환으로 외상성 화골성 근염으로도 알려져 있으며 외상, 외과적 술식, 지속적인 자극에 의하여 근육이 골화되는 질환이다. 주로 팔, 다리 근육에서 발생되며, 저작근에서 발생되는 예는 드물다. 저작근에 발생된 경우 주된 임상증상은 개구제한이며 환자는 이환부위의 동통이나 불편함을 호소하기도 한다. 본 연구는 30대 남성이 개구제한을 주소로 내원하여 임상검사와 방사선검사 후 저작근중에서 좌측 측두근과 외측 익돌근에서 발생된 국한성 화골성 근염으로 진단 내려진 증례를 보고하고자 한다. Localized myositis ossificans is a disease with the main feature of formation of heterotropic bone and fibrous tissue involving muscle. It also called traumatic myositis ossificans. Myositis ossificans is likely to occur in the femoral region or brachium but, rarely in the head and neck including the masticatory muscles. It arises from traumatic episodes caused by prolonged mouth opening, surgical procedure, local anesthesia injection. The main clinical feature is the mouth open limitation. The diagnosis of myositis ossificans is usually based on the patient's history, clinical symptoms and on imaging finding. We present the case of patient with localized myositis ossificans of the temporal and lateral pterygoid muscles.

Evaluation of Muscle Atrophy: Comparison between Limb-Girdle Muscular Dystrophies, ALS and Metabolic Myopathies (P07.197)

Objective: To study neuromuscular disorders by a quantitative measurement to evaluate muscle atrophy by MRI. Background The fibro-fatty replacement and myoedema are the most common indexes used to evaluate the muscle involvement in LGMD on MRI. However, many published scores are not quantitative and do not assess the extent of muscle atrophy in neuromuscular disorders. Design/Methods: We selected images obtained from T1 MRI sequences of the thigh muscles, at a distance of about 15 cm from the head of the femur. We measured the muscle area of the left quadriceps femoris and of the left vastus lateralis in 11 patients matched by sex and age, affected with 2 lipid myopathies, amyotrophic lateral sclerosis, FSHD, myofibrillar myopathy, metabolic myopathy, 2 LGMD2A, LGMD1F, localized myositis ossificans, aspecific myopathy. Results: Vastus lateralis muscle. The area was in average 963 ± 303 mm 2 . In this group of patients we have identified two subgroups, one including 5 patients with a high degree of atrophy ( high atrophic group ), whose values ranged from 400 to 900 mm 2 (mean 658.7), and one including 6 patients with a low degree of atrophy ( low atrophic group ), whose values ranged from 900 to 1400 mm 2 (mean 1217.8). Quadriceps femoris muscle in-toto. The measure of muscle area was in average 3711 ± 792 mm 2 . In the high atrophic group the values ranged from 2400 to 3400 mm 2 (mean 2966), while in the low atrophic group the values ranged from 3700 to 5000 mm 2 (mean 4332). Conclusions: Imaging examination may suggest a characteristic pattern of muscle involvement: i.e. in LGMD2A the posterior compartment is often involved. The values of cross sectional muscle area appeared to be useful indexes to evaluate muscle atrophy in LGMD, ALS and metabolic myopathies. The effect of drug treatment or of exercise or rehabilitation can be evaluated by quantitative muscle MRI. Disclosure: Dr. Angelini has received personal compensation for activities with Genzyme Corporation. Dr. Fanin has nothing to disclose. Dr. Peterle has nothing to disclose.

Morphoea with Myositis: A Rare Association

In this case, we describe an unusual presentation of a young woman with a rash typical of morphoea (confirmed on biopsy), who went on to develop myositis in an atypical distribution. Although the association of myositis with diffuse systemic sclerosis is well described, the link with localised scleroderma (morphoea) and myositis has not been described.

Périostéite au cours des vascularites systémiques nécrosantes : à propos de 4 observations d’une atteinte méconnue et pourtant évocatrice

Periostitis (periosteal new bone formation) is a rare manifestation of systemic necrotizing vasculitis. We searched the French Vasculitis Study Group (FVSG) database, established in 1980 and containing the data on 1762 patients with a systemic necrotizing vasculitis, i.e., polyarteritis nodosa (PAN), microscopic polyangiitis, Churg-Strauss syndrome or Wegener's granulomatosis, for those with periostitis. Herein, we describe their characteristics and outcomes. Only 4 patients with periostitis were identified. All had limited and localized PAN-like vasculitis, without poor prognosis factors. Periostitis was painful and localized to the lower limbs in all of them and associated with local myositis in 2. Pain and inflammation resolved under corticosteroids in all, but relapses or corticosteroid-dependence ultimately required the adjunction of an immunosuppressant for 3. With a median follow-up of 10 [range: 4-11] years, only 1 developed peripheral neuropathy and none progressed to a more systemic form of vasculitis, i.e., with severe visceral involvement. Physicians should be aware that periostitis, usually localized, is a potential manifestation of systemic necrotizing vasculitis, especially polyarteritis nodosa. The overall long-term outcome of these patients is good, but relapses or corticosteroid-dependence is frequent.

Hookworms of dogs and cats as agents of cutaneous larva migrans

Dogs and cats are hosts to hookworms that may cause zoonotic disease, most notably, cutaneous larva migrans. Ancylostoma braziliense is most often implicated in dermatological lesions, and Ancylostoma caninum has been associated with eosinophilic enteritis and suggested as a possible cause of diffuse unilateral subacute neuroretinitis in humans. Other manifestations include eosinophilic pneumonitis, localized myositis, folliculitis, erythema multiforme, or ophthalmological manifestations. Ancylostoma eggs are morphologically indistinguishable, which complicates epidemiological studies. Surveys of dermatologists, gastroenterologists, and ophthalmologists would help to define the incidence of these zoonotic infections. Improved diagnostic tests are needed to identify the causative species involved and understand the epidemiology of hookworm disease. This review describes the discovery of the disease, the biology of the agents, and how that biology may impact disease.

Severe Invasive Group A Streptococcal Disease with Rhabdomyolysis but without Evidence of Shock or Local Myositis

We report a presentation in an adult with <i>Streptococcus pyogenes</i> bacteremia and invasive tissue disease with rhabdomyolysis, but without evidence of toxic shock syndrome or local myonecrosis. We thus investigated how this infecting strain differed from strains known to cause toxic shock syndrome.

Infectious myositis

Infectious myositis, an infection of the skeletal muscle(s), is uncommon. This clinical entity may be caused by viral, bacterial, fungal, and parasitic pathogens. Viral etiologies typically cause diffuse myalgias and/or myositis, whereas bacteria and fungi usually lead to a local myositis which may be associated with sites compromised by trauma or surgery and are more common among immunocompromised patients. Localized collections within the muscles are referred to as pyomyositis. Other pyogenic causes of myositis include gas gangrene, group A streptococcal myonecrosis, and other types of non-clostridial myonecrosis. Early recognition and treatment of these conditions are necessary as they may rapidly become life-threatening.

Myositis Ossificans of the Hand

Extraskeletal ossification may occur in muscle and other soft tissue, The phenomenon may be classified as follows: (1) progressive Myositis ossificans, (2) traumatic localized Myositis ossificans, and (3) nontraumatic localized Myositis ossificans. The literature suggests that 75% of the localized forms occur as a result of trauma. We report a case of non traumatic myositis ossificans which involved the hypothenar region of the hand.

New host and geographic records for two protostrongylids in Dall's sheep.

Biodiversity survey and inventory have resulted in new information on the distribution of Protostrongylidae in Dall's sheep (Ovis dalli dalli) from the Northwest Territories (NT, Canada) and from Alaska (AK, USA). In 1998, Parelaphostrongylus odocoilei adults were found for the first time in the skeletal muscles of Dall's sheep in the Mackenzie Mountains (NT). Adult P. odocoilei were associated with petechial and ecchymotic hemorrhages and localized myositis; eggs and larvae in the lungs were associated with diffuse granulomatous pneumonia. Experimental infections of the slugs Deroceras laeve and Deroceras reticulatum with dorsal-spined first-stage larvae assumed to be P. odocoilei, from ground-collected feces from Dall's sheep in the Mackenzie Mountains, yielded third-stage larvae by at least 28 (in D. laeve) and 48 (in D. reticulatum) days post-infection. Third-stage larvae emerged from D. laeve between days 19 and 46 post-infection and emergence occurred both at room temperature and at 10 to 12 C. Protostrongylus stilesi were definitively identified from the lungs of Dall's sheep collected in the Mackenzie Mountains, NT in 1998. Specimens collected from sheep in the Mackenzie Mountains, NT in 1971-72, and the Alaska Range, AK in 1972 were also confirmed as P. stilesi. Lung pathology associated with adults, eggs, and larvae of P. stilesi was similar to that described in bighorn sheep (Ovis canadensis). Concurrent infections with P. odocoilei and P. stilesi in a single host have not been previously reported.

Buttock granulomas: a consequence of intramuscular injection of Sandostatin detected by In-111 octreoscan.

A 64-year-old woman with a malignant carcinoid tumor began receiving monthly treatment with 30 mg long-acting Sandostatin suspension injected intramuscularly in the buttocks along with 200 μg Sandostatin (Novartis, Hanover, NJ) subcutaneously once per day in 1994. Tc-99m MDP bone imaging showed areas of extensive metastases. To better characterize the extent of disease, In-111 pentetreotide imaging was performed, with images acquired at 24 hours. In addition to widespread disease, unusual uptake was shown in the upper outer quadrants of both buttocks, apparently at the sites of intramuscular Sandostatin injection. Recent studies of single-dose intramuscular injections have shown that Sandostatin injection may lead to localized granulomatous myositis and granuloma formation. In this patient, two large areas of increased uptake located in both buttocks are seen at the sites of repeated intramuscular injection of Sandostatin.

A novel missense mutation (C30S) in the gene encoding tumor necrosis factor receptor 1 linked to autosomal-dominant recurrent fever with localized myositis in a French family

Objective To characterize both phenotypic (clinical features and magnetic resonance imaging [MRI] findings) and genotypic aspects of autosomal-dominant recurrent fever, also known as tumor necrosis factor receptor (TNFR)–associated periodic syndrome (TRAPS), in a French family and to investigate the role of the mutated 55-kd tumor necrosis factor α (TNFα) receptor (TNFR1) in the pathogenesis of the disease. Methods The coding region of TNFR1 was sequenced in 2 individuals with TRAPS (the propositus and her grandfather) and in 3 clinically unaffected relatives. Expression of soluble TNFR1 (sTNFR1) was investigated in 3 of the family members carrying a C30S mutation in TNFR1, and was compared with the levels of soluble TNFR2 (sTNFR2) by enzyme-linked immunosorbent assay. The membrane TNFR1 expression was then compared with membrane TNFR2 levels at the surface of peripheral blood mononuclear cells by flow cytometric analysis. The clinical heterogeneity in this French family was investigated by searching polymorphic variants in the TNFα promoter by DNA sequencing. Results Both the disease course and the clinical presentation in the propositus were highly indicative of TRAPS. MRI study of the segmental inflammatory process in the limbs showed abnormal signals in the muscle and subcutaneous tissue without involvement of adjacent joints or fascia. A novel missense mutation, C30S, in the first extracellular N-terminal cysteine-rich domain (CRD1) of TNFR1 was characterized in the propositus, her affected grandfather, and her clinically unaffected father. Expression of membrane TNFR1 at the surface of monocytes and polymorphonuclear leukocytes, as well as the levels of sTNFR1 in serum when the disease was not active were not modified in the 3 individuals carrying the TNFR1 C30S mutation. In contrast, during attacks, sTNFR1 levels remained abnormally low, as compared with the levels in unrelated patients with active adult-onset systemic Still's disease. The clinical heterogeneity could not be explained by a polymorphic variant in the TNFα promoter. Conclusion TRAPS is a distinct clinical and radiologic disease entity that is responsible for recurrent fever and migratory cellulitis-like processes with localized myositis. We have identified a novel TNFR1 mutation, C30S, that is located in the CRD1 domain in a French family affected by the disease. This mutation seems to affect the level of sTNFR1, which did not increase in the propositus during inflammatory attacks.

A novel missense mutation (C30S) in the gene encoding tumor necrosis factor receptor 1 linked to autosomal-dominant recurrent fever with localized myositis in a French family.

To characterize both phenotypic (clinical features and magnetic resonance imaging [MRI] findings) and genotypic aspects of autosomal-dominant recurrent fever, also known as tumor necrosis factor receptor (TNFR)-associated periodic syndrome (TRAPS), in a French family and to investigate the role of the mutated 55-kd tumor necrosis factor alpha (TNFalpha) receptor (TNFR1) in the pathogenesis of the disease. The coding region of TNFR1 was sequenced in 2 individuals with TRAPS (the propositus and her grandfather) and in 3 clinically unaffected relatives. Expression of soluble TNFR1 (sTNFR1) was investigated in 3 of the family members carrying a C30S mutation in TNFR1, and was compared with the levels of soluble TNFR2 (sTNFR2) by enzyme-linked immunosorbent assay. The membrane TNFR1 expression was then compared with membrane TNFR2 levels at the surface of peripheral blood mononuclear cells by flow cytometric analysis. The clinical heterogeneity in this French family was investigated by searching polymorphic variants in the TNFalpha promoter by DNA sequencing. Both the disease course and the clinical presentation in the propositus were highly indicative of TRAPS. MRI study of the segmental inflammatory process in the limbs showed abnormal signals in the muscle and subcutaneous tissue without involvement of adjacent joints or fascia. A novel missense mutation, C30S, in the first extracellular N-terminal cysteine-rich domain (CRD1) of TNFR1 was characterized in the propositus, her affected grandfather, and her clinically unaffected father. Expression of membrane TNFR1 at the surface of monocytes and polymorphonuclear leukocytes, as well as the levels of sTNFR1 in serum when the disease was not active were not modified in the 3 individuals carrying the TNFR1 C30S mutation. In contrast, during attacks, sTNFR1 levels remained abnormally low, as compared with the levels in unrelated patients with active adult-onset systemic Still's disease. The clinical heterogeneity could not be explained by a polymorphic variant in the TNFalpha promoter. TRAPS is a distinct clinical and radiologic disease entity that is responsible for recurrent fever and migratory cellulitis-like processes with localized myositis. We have identified a novel TNFR1 mutation, C30S, that is located in the CRD1 domain in a French family affected by the disease. This mutation seems to affect the level of sTNFR1, which did not increase in the propositus during inflammatory attacks.

Painful small-fibre multifocal mononeuropathy and local myositis following influenza B infection

A 47-year-old man experienced multifocal mononeuropathy and putative ganglionopathy associated with influenza B infection, characterized by aching and dysesthesia in the right arm and left leg with normal deep sense. He displayed muscle atrophy in the affected limbs, which might have resulted from local myositis or a disorder similar to neuralgic amyotrophy. Sural nerve biopsy revealed a severe loss of unmyelinated and thinly myelinated fibres, consistent with a small fibre neuropathy, without evidence of angiopathy or inflammation. We could not detect any other cause of the neuropathy except influenza B. In this case, it may be inferred that small-diameter neurons in the dorsal root ganglia and thinly- or nonmyelinated fibres were selectively involved through a post-infectious immune process. To our knowledge, small fibre neuropathy following influenza B has never been reported.

Relapsing, Localized Myositis of the Head and Neck After a Hornet Sting

Localized myositis is a result of heterogenous group of disorders associated with variable clinical, enzyme and pathologic findings. We report the case of a young woman who developed progressive, relapsing myositis of her head and neck after a hornet sting. We provide an update about the clinical spectrum of different forms of localized myositis.

Calf Pain and Swelling (Pseudothrombophlebitis) Caused by Rupture of the Plantaris Muscle/Tendon

Painful swelling of the calf is a common clinical problem. Distinguishing deep venous thrombosis from pseudothrombophlebitis can be difficult Pseudothrombophlebitis syndrome has been associated with ruptured/dissecting popliteal synovial cysts, localized myositis, inflammatory pseudotumor, popliteal artery aneurysm, and ruptured gastrocnemius, popliteal and/or plantaris tendon/muscles. In this report, we describe two patients for whom magnetic resonance imaging rapidly and accurately identified the cause of pseudothrombophlebitis, thus helping to avoid further testing and unnecessary anticoagulation.