# A Case of Anti-TIF1γ Antibody-Positive Dermatomyositis Associated With Malignancy

## TL;DR

This paper reports a case of a man with a rare autoimmune muscle disease linked to lung cancer, highlighting the importance of detecting specific antibodies for early diagnosis.

## Contribution

The paper emphasizes the strong association between anti-TIF1γ antibodies and malignancy in dermatomyositis.

## Key findings

- A 67-year-old man with anti-TIF1γ-positive dermatomyositis was found to have concurrent lung cancer.
- Anti-TIF1γ antibodies are strongly associated with malignancy in patients with dermatomyositis.
- Early detection of these antibodies can lead to prompt diagnosis and treatment of cancer.

## Abstract

Dermatomyositis (DM) is a rare acquired autoimmune myopathy characterized by proximal muscle weakness, inflammation, and a typical skin rash. It is considered one of the idiopathic inflammatory myopathies (IIM), a group of heterogeneous systemic diseases that include DM, polymyositis, and inclusion body myositis. A significant portion of patients with IIM, particularly adults, can have an association with malignancy, usually preceded by muscle and skin symptoms.

We report a case of a 67-year-old man who presented to the accident and emergency department with a six-week history of proximal myopathy in the upper and lower limbs and a skin rash. After a series of investigations, the patient was diagnosed with anti-TIF1γ-positive DM and concurrent lung cancer.

DM is a paraneoplastic disorder that should always prompt a search for malignancy. Early detection of anti-TIF1γ autoantibodies can facilitate an early diagnosis of CAD, allowing for prompt therapeutic interventions. Several autoantibodies with different clinical and prognostic significance have been detected in IIM. However, the recently discovered anti-TIF1γ antibodies appear to be strongly associated with malignancy.