BACKGROUND: Necrotizing myopathies and muscle necrosis can be caused by immune-mediated mechanisms, drugs, ischemia, and infections, and differential diagnosis may be challenging.
METHODS: We describe a case of diabetic myonecrosis complicated by pyomyositis and abscess caused by Escherichia coli. A white woman in her late forties was admitted to the hospital with a 1.5 week history of bilateral swelling, weakness, and mild pain of the lower extremities and inability to walk. She had a history of type 1 diabetes complicated by diabetic retinopathy, neuropathy, nephropathy, and end-stage renal disease. C-reactive protein was 203 mg/l, while creatinine kinase was only mildly elevated to 700 IU/l. Magnetic resonance imaging of her lower limb muscles showed extensive edema, and muscle biopsy was suggestive of necrotizing myopathy with mild inflammation. No myositis-associated or myositis-specific antibodies were detected. Initially, she was suspected to have seronegative immune-mediated necrotizing myopathy, but later her condition was considered to be explained better by diabetic myonecrosis with multifocal involvement. Her symptoms alleviated without any immunosuppressive treatment. After a month, she developed new-onset and more severe symptoms in her right posterior thigh. She was diagnosed with emphysematous urinary tract infection and emphysematous myositis and abscess of the right hamstring muscle. Bacterial cultures of drained pus from abscess and urine were positive for Escherichia coli. In addition to abscess drainage, she received two 3-4-week courses of intravenous antibiotics. In the discussion, we compare the symptoms and findings typically found in pyomyositis, immune-mediated necrotizing myopathy, and diabetic myonecrosis (spontaneous ischemic necrosis of skeletal muscle among people with diabetes). All of these diseases may cause muscle weakness and pain, muscle edema in imaging, and muscle necrosis. However, many differences exist in their clinical presentation, imaging, histology, and extramuscular symptoms, which can be useful in determining diagnosis. As pyomyositis often occurs in muscles with pre-existing pathologies, the ischemic muscle has likely served as a favorable breeding ground for the E. coli in our case.
CONCLUSIONS: Identifying the etiology of necrotizing myopathy is a diagnostic challenge and often requires a multidisciplinary assessment of internists, pathologists, and radiologists. Moreover, the presence of two rare conditions concomitantly is possible in cases with atypical features.

Diabetic muscle infarction (DMI) is a rare yet serious complication that has been strongly associated with uncontrolled diabetes, although other risk factors are unclear. DMI is an uncommon complication of diabetes with a lack of structured guidelines for evaluation or management. End-stage renal disease (ESRD) could have further implications in patients with DMI in terms of management given that nonsteroidal anti-inflammatory drugs (NSAIDs), which have been shown to reduce the recovery times and recurrence of DMI, could be contraindicated. We present a rare case of DMI in an African American man with ESRD who presented for new-onset right lower-extremity pain and swelling. We discuss the challenges involved with the diagnosis and treatment of this rare condition. This case adds to the knowledge of DMI, which is limited because of the low incidence of this condition, and it helps us understand how this condition affects the African American population and patients with ESRD.

Diabetic myonecrosis is a rare and poorly understood complication of long-standing, inadequately controlled diabetes mellitus. Theoretical mechanisms contributing to the pathophysiology of diabetic myonecrosis include microvascular complications due to advanced glycation end-products, ischemia-reperfusion injuries, and dysregulated coagulation-fibrinolysis activity. Case reports of diabetic myonecrosis most commonly describe diabetic patients with chronically poor glycemic control who experience isolated swelling and severe pain in a unilateral lower limb with no signs of infection or systemic toxicity. Due to the rarity of this condition, there are currently no treatment guidelines. This case describes a 58-year-old male with a history of uncontrolled diabetes who presented with diabetic ketoacidosis with mixed hypovolemic and septic shock. Diabetic myonecrosis was incidentally discovered in the patient\'s right latissimus dorsi with CT imaging and subsequent surgical exploration. Spontaneous diabetic myonecrosis may mimic several other serious conditions and elicit suboptimal management strategies, particularly in the context of atypical presentations.

Diabetic myonecrosis is an infrequently encountered complication of poorly managed type 2 diabetes. Despite its relative rarity, early detection and appropriate management can yield favorable outcomes. This case report details the presentation, diagnosis, and management of a 53-year-old male patient with a history of type 2 diabetes who presented with acute-onset pain, swelling of the muscles, and weakness. Following a battery of laboratory investigations, radiological imaging, and a muscle biopsy, the patient was diagnosed with diabetic myonecrosis. The patient was treated conservatively with analgesics, physiotherapy, and optimization of glycemic control, significantly improving muscle strength and function. This case highlights the necessity of considering diabetic myonecrosis as a potential differential diagnosis in diabetic patients who present with sudden muscle weakness and discomfort.

Diabetic myonecrosis, also known as diabetic muscle infarct, is a rare complication of diabetes mellitus, generally associated with poor glycemic control. It is often difficult to diagnose due to its nonspecific presentation and lack of awareness of the complication. Routine laboratory investigations often do not aid in diagnosis. Magnetic resonance imaging (MRI) may assist in diagnosis but is not routinely ordered due to cost-effectiveness and nonspecific radiologic appearance. Muscle biopsy can provide a definite diagnosis; however, it is often avoided due to its invasiveness. Treatment consists of glycemic control, rest, and analgesics for pain control. Our case describes a 42-year-old male with uncontrolled diabetes who presented with four weeks of progressively worsening right-sided lower extremity pain. The patient was taken to the operating room for concern for necrotizing fasciitis; however, it was ultimately ruled out. A diagnosis of diabetic myonecrosis was made. Recommendations were given for strict blood sugar control and to start aspirin 81 mg daily. The patient was later seen in the outpatient clinic with improvement in the lower extremity pain.

Diabetic myonecrosis or diabetic muscle infarction (DMI), is a very rare and under-recognised complication of poorly controlled long-standing diabetes mellitus. We report a case of a 59-year-old male, who had diabetes for ten years. He presented with bilateral thigh pain of insidious onset for three months and difficulty in walking, with a similar episode in his right thigh in 2015. Creatine phosphokinase (CPK) was one and half times the normal upper limit. Magnetic resonance imaging (MRI) of his thighs showed symmetrical bulky muscles with hyperintensities on T2-weighted and short tau inversion recovery (STIR) images, supporting a clinical diagnosis of idiopathic inflammatory myositis (IIM). However, a review of histopathology slides of a muscle biopsy from the right vastus lateralis performed in 2015 showed muscle fibre ischaemic necrosis suggestive of muscle infarction. Thus a diagnosis of recurrent diabetic myonecrosis was made and the patient was treated with bed rest, opioids and aspirin with gradual recovery.

Diabetic myonecrosis (DMN) is a rare microangiopathic disorder that can present as an acutely painful and swollen limb in patients with established diabetes mellitus. The condition can be diagnosed noninvasively with magnetic resonance imaging and resolves with analgesia, bed rest, and glycemic control. Due to a relative lack of awareness regarding the condition, avoidable interventions such as muscle biopsies and even surgery are sometimes pursued, which have been associated with prolonged recovery times. The majority of patients with DMN have diabetic nephropathy, yet this condition is not widely recognized in the nephrology community, resulting in delayed diagnosis and patients undergoing unnecessary and potentially harmful investigations. There is therefore a need for increased awareness of the condition among renal physicians. Here, we report the cases of two patients on hemodialysis who were ultimately diagnosed with DMN, along with a review of the literature.

Diabetic myonecrosis (DMN) is an under-diagnosed complication of long-standing poorly controlled diabetes mellitus. It presents as abrupt pain and swelling of the extremity, mostly lower limbs. Diagnosis is often delayed as it mimics a number of clinical entities such as deep vein thrombosis (DVT), cellulitis, necrotizing fasciitis and malignancy. Failure to properly identify this condition can result in increased morbidity through exposure to unnecessary tests and biopsy. A 56-year-old male with a history of complicated type 2 diabetes mellitus, hypertension presented to emergency with gradually worsening left calf pain for last 2 weeks. A lower-extremity venous Doppler was negative for DVT. Magnetic resonance imaging (MRI) was suggestive of muscle edema likely of inflammatory etiology. Muscle biopsy revealed myonecrosis with ischemic myopathy and was negative for vasculitis or inflammatory myopathy. He was managed conservatively and his symptoms resolved in 4 weeks. After 6 months he had recurrence in right thigh which was managed conservatively too. Given these findings, a diagnosis of recurrent diabetic myonecrosis was made. Myonecrosis is a less known microvascular complications of diabetes and should always be keep in mind when evaluating a diabetic patient with muscle pain. Diagnosis can be made on MRI in appropriate clinical settings. The clinical course is usually self-limiting and patients respond well to supportive medical therapy that involves bed rest, strict glycemic control along with analgesic.

Patients presenting with a painful swollen leg are not infrequently encountered at the emergency department and can pose a diagnostic dilemma for attending physicians. The potential causes of leg pain and swelling include trauma, infection, inflammation, and neurogenic, vascular, and iatrogenic conditions; with magnetic resonance imaging (MRI) being an important tool in evaluation. We describe the MRI features of various conditions causing painful swollen legs. We also discuss the differential diagnosis and the useful clinical and laboratory findings that radiologists should be aware of, in order to arrive at an accurate diagnosis.

A 51-year-old female with a history of type 1 diabetes mellitus (DM) presented with sudden onset of pain and swelling of the left thigh. Her initial evaluation revealed mildly elevated erythrocyte sedimentation rate and creatine phosphokinase. Venous and arterial Doppler studies were negative for DVT and arterial thrombus. Further imaging with CT scan and then MRI revealed an irregular, enhancing space-occupying lesion of the left upper and mid-thigh. Subsequent muscle biopsy showed myonecrosis and proliferative myositis. Both findings are consistent with diabetic myonecrosis, which is a microvascular complication of long-standing poorly controlled DM. The patient was treated with analgesics, supportive care, and optimization of glycemic control. While short-term prognosis is good with adequate healing in a few weeks to several months, long-term prognosis is poor due to underlying extensive vascular disease. Although radiological findings are very suggestive of the diagnosis, most clinicians still need tissue biopsy to rule out other serious conditions such as infections and malignancy.