Inflammatory myopathies and lymphoma

Dermatomyositis Associated With High-Grade B-Lymphoproliferative Disorders: A Case Report and Literature Review

Dermatomyositis (DM) and polymyositis are idiopathic inflammatory myopathies (IIMs), most associated with solid organ malignancies, and less commonly hematological malignancies. We discuss a case of DM associated with diffuse large B-cell lymphoma, followed by a review of literature on the pathogenesis, clinical course, treatment, and prognosis. Various challenges with the diagnosis and management of underlying lymphoproliferative disorders (LPDs) in patients with IIM are discussed. The case demonstrates the importance of being vigilant of the association between IIM and LPD. Cancer screening in patients with IIM is discussed, including the recently published International Guideline for IIM-Associated Cancer Screening. More research is required to address knowledge gaps in cancer screening in IIM.

Follicular lymphoma associated paraneoplastic myositis

This case illustrates an unusual presentation of paraneoplastic myositis in stage IV follicular lymphoma managed with high‐dose steroids, a previously unreported entity in the literature.

The diagnostic work-up of cancer-associated myositis

PURPOSE OF REVIEW

Despite the well-recognized association between malignancy and myositis, definite data indicating the best strategy for diagnosing cancer in myositis patients is lacking. In this article, we review the data on cancer screening in patients with myositis, and propose an algorithm for this purpose based on recently published data.

RECENT FINDINGS

Evidence has recently emerged supporting blind screening in patients with certain myositis phenotypes. In addition to the clinical examination, imaging techniques such as PET/computed tomography scanning and whole-body MRI, and determination of the autoantibody profile beyond anti-TIF1γ antibody, the well known cancer biomarker in dermatomyositis, will help the clinician face this complex clinical situation. Molecules related to the checkpoint inhibitor pathway, specifically soluble programmed death 1, may also have a role in the diagnostic work-up of cancer in myositis. In the future, blood tests analysing circulating DNA will certainly help in detecting patients with cancer-associated myositis (CAM).

SUMMARY

A step forward has been achieved in the pathway to establish optimal cancer screening for myositis patients. International consensus guidelines for an effective diagnostic work-up of CAM are in progress and will be of paramount importance to improving the outcome in these patients.

Myalgia caused by chronic myositis associated with plasmacytosis: a case report

Background

Cutaneous and systemic plasmacytosis are skin disorders characterized by cutaneous polyclonal plasma cell infiltration accompanied by polyclonal hypergammaglobulinemia. Cutaneous plasmacytosis involvement is limited to the skin, mainly on the face and trunk, while systemic plasmacytosis also involves 2 or more organ systems. However, there have been no reports of inflammatory myositis due to plasmacytosis. Here, we report a patient with plasmacytosis who developed myalgia and easy fatigability due to inflammatory myositis.

Case presentation

A 54-year-old man with cutaneous plasmacytosis on the face, chest, and back complained of a history of atypical facial and lower leg pain and easy fatigability since the age of 45 years. Muscle-strength tests revealed bilateral trivial gastrocnemius weakness with myalgia. The results of routine blood analysis, including creatine kinase and thyroid function, were normal, but levels of several inflammation markers and autoantibodies were elevated. Additionally, lower leg magnetic resonance imaging and gastrocnemius muscle biopsy revealed inflammatory myositis mimicking polymyositis. His plasmacytosis, myalgia, and lower leg weakness were ameliorated by prednisolone.

Conclusion

The patient was diagnosed with inflammatory myositis due to plasmacytosis. Given that plasmacytosis has previously been reported to disrupt the immune status, myositis in this patient might have been associated with abnormal autoimmune inflammation. Neurologists and physicians should thus be aware that plasmacytosis might be associated with inflammatory myositis accompanied by myalgia.

Juvenile dermatomyositis/polymyositis and lymphoma

In patients with juvenile dermatomyositis/polymyositis (JDM/PM), malignancy is a rare phenomenon. An extensive workup for neoplastic disease is not routinely indicated, but should be considered if unusual physical findings are noted at JDM/PM diagnosis or during follow-up period. The objective of this literature review was to assess for any association between, and disease profile of, JDM/PM and lymphoma in childhood. Risk determinants of the possible development of lymphoma in the pediatric population with JDM/PM appear to be the degree and duration of inflammatory activity with chronic B-cell activation and/or antigen stimulation; a paraneoplastic relationship is unlikely.