Journals | Policy | Permission

This journal has moved to cii.elmerpub.com Please go to the new site to make submissions

Clinical Infection & Immunity

Case Report

Volume 9, Number 1, March 2024, pages 20-24

Polymyositis, COVID-19 and Rectal Carcinoma: A Rare Case Presentation

Polymyositis (PM) is one of the idiopathic inflammatory myopathies (IIMs) characterized by muscle weakness, elevated muscle enzymes, distinctive electromyographic (EMG) changes and inflammatory muscle infiltrates [1]. Association of malignancy is more commonly seen with dermatomyositis (DM) than PM [2]. Coronavirus disease 2019 (COVID-19) is a major pandemic affecting the whole world. It is now known that COVID-19 can trigger the emergence of autoimmune diseases in genetically susceptible individuals [3]. We describe a case of PM in a patient with rectal adenocarcinoma who was admitted for COVID-19.

A 73-year-old male from Kathmandu, a retired physician by profession, presented to the emergency room with generalized weakness associated with fever for 1 week. He had self-tested for COVID-19 antigen at home which was positive 6 days prior to presentation. His past medical history included diabetes mellitus and systemic hypertension for 20 years, coronary artery disease (triple vessel disease) for which he had undergone coronary artery bypass grafting and percutaneous coronary intervention 6 months before this presentation. He had also undergone low anterior resection for mid-rectal carcinoma 1 month prior. He had received neo-adjuvant chemotherapy (two cycles) with carboplatin-based therapy 6 months before and 28 sessions of radiotherapy (last session 3 months back). His medications included aspirin 75 mg once daily, clopidogrel 75 mg once daily, metoprolol succinate 25mg once daily, metformin 1 g twice daily, losartan 50 mg once daily and rosuvastatin 10 mg once daily. He was a social drinker and non-smoker. His family history was unremarkable.

On examination in the emergency room, he was conscious and oriented. His pulse rate was 113/min, regular, blood pressure was 150/80 mm Hg, temperature was 97.2 °F and oxygen saturation was 94% on room air. His respiratory, cardiovascular and abdominal examinations were unremarkable. His nervous system examination was not properly carried out in the emergency room but looked grossly normal. His laboratory tests showed anemia with acute kidney injury with raised inflammatory markers and transaminases (Table 1) and his polymerase chain reaction (PCR) for COVID-19 was positive. His chest X-ray was normal. He was admitted with the provisional diagnosis of mild COVID-19 with acute kidney injury. His metformin and losartan were held in view of acute kidney injury. During admission in the ward, he complained of increasing limb weakness. His renal function started getting worse and his urine culture grew Escherichia coli sensitive to meropenem. His serum potassium started decreasing (Table 1) after a couple of days, therefore his weakness was assigned to hypokalemia. His thyroid function test was also suggestive of hypothyroidism which was presumed to have contributed to the weakness. At the same time, he was complaining of bowel incontinence which was concluded to be due to his recent rectal surgery.

Click to view

Table 1. Laboratory Investigations

On the ninth day of admission, he was still complaining of weakness of his limbs and inability to get out of bed. At this time, a full neurological examination was done. The patient was conscious, well oriented to time, place and person, his higher mental function and sensory examinations were intact. However, he had mild atrophy of the proximal muscles bilaterally but no fasciculations, his muscle power was 2/5 in bilateral shoulders (abduction, adduction, flexion, and extension), 1/5 in bilateral hips (flexion, extension, abduction, and adduction) and 2/5 in neck flexors and extensors. He had global areflexia and his plantars were bilaterally flexors. His distal muscle power was normal and he had no history of dysphagia, dysarthria, diplopia or aspiration. Meanwhile his liver transaminases were increasing (Table 1) for which no etiology could be found. At this time, Guillain-Barre syndrome (GBS) was strongly considered as one of the differentials as the patient had proximal weakness with areflexia. Lumbar puncture and nerve conduction test did not show any feature suggestive of GBS. Muscle enzymes including creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) were sent as PM was another possibility. CPK and LDH were markedly elevated (Table 1), therefore a working diagnosis of PM was made. A magnetic resonance imaging (MRI) of bilateral thighs showed increased signals in short tau inversion recovery (STIR) sequence (Fig. 1) which was also in favor of muscle inflammation. He was then started on prednisolone at 1 mg/kg along with other supportive treatment. The patient started feeling better in a couple of days after starting prednisolone. He underwent both active and passive physiotherapy during the ward admission. Finally, he was planned for discharge on the 16th day of admission (seventh day of steroid). His power in left shoulder had improved to 3/5, and bilateral hips to 2/5 and that in other groups was stationary. His CPK had started decreasing and his renal function was normal (Table 1). Meanwhile his antinuclear antibody (ANA) and myositis profile came back negative. His muscle biopsy came back showing features of inflammatory myositis with both perimysial and endomysial infiltration of inflammatory cells (Fig. 2). During follow-up at 1 week, his power in bilateral upper limbs had improved to 4-/5, bilateral lower limbs to 3/5 and neck muscles to 3/5. His CPK and transaminases had come down to normal (Table 1). The patient is currently under tapering steroid along with methotrexate and getting active physiotherapy.

Click for large image

Figure 1. (a) Axial T2WI shows symmetrical T2 high signal intensity within the bilateral pectineus and obturator externus muscles (arrow). (b) Axial STIR image shows symmetrical high signal intensity within the bilateral pectineus and obturator externus muscles (arrow). (c) Coronal STIR image shows high signal intensity within the bilateral thigh muscles (white arrows). T2W1: T2-weighted image; STIR: short tau inversion recovery.

Click for large image

Figure 2. (a) Muscle biopsy showing perimysial and endomysial inflammatory cell infiltrate (arrows) (H&E, × 10). (b) Muscle biopsy showing degeneration and fibrosis (arrow) (H&E, × 10). H&E: hematoxylin and eosin.

PM is characterized by chronic inflammation of skeletal muscle and manifested by proximal muscle weakness, elevations in creatine kinase, typical EMG changes with polyphasic potentials and muscle biopsy findings of a necrotizing inflammatory process [4]. The association between cancer and PM has been supported by various epidemiologic studies. The associated risk varies markedly due to substantial differences among various studies [5]. The type of cancer associated with PM depends on the geographic location and is most commonly associated with ovarian, lung, breast and nasopharyngeal cancers [6, 7]. Various population-based studies have shown association of colorectal cancer with DM [5, 6]. However, its association with PM is limited to few case reports [8-11]. The diagnosis of cancer can be before, after or simultaneously with myositis [6]. Studies have shown that the peak incidence of cancer detection is within the first year of diagnosis of myositis [6]. Our patient had developed malignancy prior to the onset of myositis. Since he had already undergone chemotherapy, radiotherapy and surgical resection before the current symptoms, question arises whether it was something else that triggered the myositis.

Various viruses have been implicated in triggering inflammatory myopathy. They include coxsackie B virus, parvovirus, enterovirus, human T-cell lymphotropic virus (HTLV-1), and human immunodeficiency virus (HIV) [12]. Several hypotheses have been proposed for the pathogenesis of virus-mediated muscle inflammation. One possible explanation may be latent infection of the muscle by the virus thereby triggering chronic inflammation, another could be alteration of host proteins that can act as a foreign antigen and yet another mechanism could be molecular mimicry [12].

Recently severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has also been recognized as a trigger of various autoimmune diseases. The time between symptoms of viral illness and onset of autoimmune symptoms ranged from 2 to 33 days (mean of the 33 cases: 9.8 days) in one systematic review [13]. Our patient also developed symptoms of myositis during this period. Therefore, it is possible that COVID-19 might have triggered the current illness of the patient. Muscle involvement could be in the form of acute viral myositis, rhabdomyolysis, DM, paraspinal myositis and an asymptomatic rise in CPK [14]. Our patient most probably had PM since he did not have any features suggestive of DM and he fulfilled three out of four criteria for PM [15]. The mechanism of muscle injury is unknown but various hypotheses have been proposed. One mechanism could be direct entry of the virus using the angiotensin-converting enzyme 2 (ACE-2) receptor leading to direct muscle damage. Other possible mechanisms include immune complex deposition, release of myotoxic cytokines, damage due to homology between muscle antigen and viral particles and adsorption of viral particles on myocyte membrane leading to immune activation [16].

Our patient had both malignancy and COVID-19 which may both have played a role in the causation of disease. Whatever is the underlying pathophysiology, our patient recovered dramatically within a short period of time but it remains to be seen if he needs prolonged immunosuppression similar to any other PM or if he can be taken off immunosuppressives in the future.

Generalized weakness in an elderly patient should always raise the suspicion of PM especially in the background of malignancy. Further research is needed in order to prove its association with COVID-19.

Acknowledgments

None to declare.

Financial Disclosure

None to declare.

Conflict of Interest

None to declare.

Informed Consent

Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

Author Contributions

UPR conceived the original idea. UPR and SP wrote the manuscript with support from BS and PRR. PRR and BS provided the images. UPR supervised the project. All authors contributed to the final manuscript.

Data Availability

The authors declare that data supporting the findings of this study are available within the article.

1. Tieu J, Lundberg IE, Limaye V. Idiopathic inflammatory myositis. Best Pract Res Clin Rheumatol. 2016;30(1):149-168.
   doi pubmed
2. Ungprasert P, Leeaphorn N, Hosiriluck N, Chaiwatcharayut W, Ammannagari N, Raddatz DA. Clinical features of inflammatory myopathies and their association with malignancy: a systematic review in asian population. ISRN Rheumatol. 2013;2013:509354.
   doi pubmed pmc
3. Ehrenfeld M, Tincani A, Andreoli L, Cattalini M, Greenbaum A, Kanduc D, Alijotas-Reig J, et al. Covid-19 and autoimmunity. Autoimmun Rev. 2020;19(8):102597.
   doi pubmed pmc
4. Strauss KW, Gonzalez-Buritica H, Khamashta MA, Hughes GR. Polymyositis-dermatomyositis: a clinical review. Postgrad Med J. 1989;65(765):437-443.
   doi pubmed pmc
5. Zampieri S, Valente M, Adami N, Biral D, Ghirardello A, Rampudda ME, Vecchiato M, et al. Polymyositis, dermatomyositis and malignancy: a further intriguing link. Autoimmun Rev. 2010;9(6):449-453.
   doi pubmed
6. Chen YJ, Wu CY, Huang YL, Wang CB, Shen JL, Chang YT. Cancer risks of dermatomyositis and polymyositis: a nationwide cohort study in Taiwan. Arthritis Res Ther. 2010;12(2):R70.
   doi pubmed pmc
7. Hill CL, Zhang Y, Sigurgeirsson B, Pukkala E, Mellemkjaer L, Airio A, Evans SR, et al. Frequency of specific cancer types in dermatomyositis and polymyositis: a population-based study. Lancet. 2001;357(9250):96-100.
   doi pubmed
8. Rominiyi O, Broman DM, Rajaganeshan R, Selvasekar CR. Colon cancer presenting with polymyositis-A case report. Int J Surg Case Rep. 2011;2(7):225-227.
   doi pubmed pmc
9. Nyui S, Osanai H, Ohba S, Masuoka H, Yoshida Y. Relapse of colon cancer followed by polymyositis: report of a case and review of the literature. Surg Today. 1997;27(6):559-562.
   doi pubmed
10. Tagawa A, Kashima R, Kaneda K, Nakayama M, Ono S, Shimizu N. Polymyositis successfully treated with surgical resection of colon cancer. Eur Neurol. 2000;44(4):251-252.
    doi pubmed
11. Tsavaris N, Karargyris G, Pikazis D, Vadiaka M, Kosmas C, Sakellaropoulos N, Vaiopoulos G. Adenocarcinoma of the colon presenting as polymyositis: case report. J Chemother. 2002;14(1):102-105.
    doi pubmed
12. Adler BL, Christopher-Stine L. Triggers of inflammatory myopathy: insights into pathogenesis. Discov Med. 2018;25(136):75-83.
    pubmed pmc
13. Saad MA, Alfishawy M, Nassar M, Mohamed M, Esene IN, Elbendary A. COVID-19 and autoimmune diseases: a systematic review of reported cases. Curr Rheumatol Rev. 2021;17(2):193-204.
    doi pubmed
14. Saud A, Naveen R, Aggarwal R, Gupta L. COVID-19 and Myositis: What We Know So Far. Curr Rheumatol Rep. 2021;23(8):63.
    doi pubmed pmc
15. Bohan A, Peter JB. Polymyositis and dermatomyositis (second of two parts). N Engl J Med. 1975;292(8):403-407.
    doi pubmed
16. Paliwal VK, Garg RK, Gupta A, Tejan N. Neuromuscular presentations in patients with COVID-19. Neurol Sci. 2020;41(11):3039-3056.
    doi pubmed pmc

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial 4.0 International License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Clinical Infection and Immunity is published by Elmer Press Inc.