Wong‐type dermatomyositis associated with parotid gland tumor and anti‐TIF1‐γ antibody

Wong-type dermatomyositis (DM), initially reported in 1969 [1], is a rare variant of DM. It is characterized by hyperkeratotic follicular papules reminiscent of the follicular papular pityriasis rubra pilaris (PRP). Thirty-two cases of Wong-type DM have been reported earlier [1–4]. Unlike classic DM, the incidence of malignant tumors in Wong-type DM remains unclear [5]. The anti-transcription intermediary factor 1 (TIF1)-γ antibody is a myositis-specific autoantibody (MSA) that has been identified in cases of cancer-associated DM [6]. Here, we report a case of Wong-type DM associated with a parotid gland tumor that displayed a cancer-associated DM phenotype and was positive for anti-TIF1-γ antibody. A 36-year-old woman presented to our department with facial edematous erythema and keratosis papules on the trunk and limbs after two cycles of oral contraceptive therapy for polycystic ovary syndrome. The patient presented with a “dark face” (facial lesions were more dark-red in color) [7] (Figure 1a), “red-on-white” patches (hypopigmented macules/patches associated with focal, follicular, telangiectatic erythema) on the back (Figure 1b), Gottron’s papules on the metacarpal and interphalangeal joints (Figure 1c), Gottron’s sign, V sign, shawl sign, periungual telangiectasias, and poikilodermatous appearance with hyperkeratotic follicular papules on the back, trunk, and limbs (Figure 1 b–d). A skin biopsy specimen obtained from the right thigh showed orthohyperkeratosis and invagination with a keratotic plug, basal cell liquefaction, superficial dermal edema, telangiectasia, and mild perivascular lymphohistiocytic infiltrate (Figure 2a). A muscle biopsy of the right quadriceps femoris showed a small amount of lymphocyte infiltration around the muscle bundles and small blood vessels (Figure 2b). Blood tests revealed normal creatine kinase (CK) and lactate dehydrogenase (LDH) levels. Magnetic resonance imaging of muscles revealed abnormal signal foci in bilateral gluteal muscles and muscles around the hip. Antinuclear antibodies and antibodies to extractable nuclear antigen were negative. Serum anti-TIF1-γ antibody was positive (114.789 U/ ml, negative: < 50 U/ml) by enzyme-linked immunosorbent assay. Subsequently, screening for internal malignancy was Clinical Letter