Primary lung cancer revealed by dermatomyositis and detected by whole-body scintigraphy with 99mTc-HMDP

摘要

Dermatomyositis, an inflammatory muscle disease probably related to dysimmunity, is associated with character skin eruptions. Dermatomyositis is often associated with cancer (15 to 40% of cases depending on the series). All histological types and all cancer localizations observed in the general population can be associated with dermatomyositis. We report the case of a patient with small-cell lung cancer revealed by dermatomyositis appearing by a diffuse and intense uptake of 99mTc-HMDP in the whole-body scintigraphy.There have been few descriptions of this association in the literature. Certain clinical features of dermatomyositis would be predictive of its paraneoplastic nature. Prognosis is very poor. Treatment is basically dictated by the underlying neoplasia. Introduction 99m-Tc HMDP compounds have the ability to detect nonosseous disorders. Muscular uptake on bone scintigraphy has been reported in various conditions including rhabdomyolysis, inflammatory muscle disease, traumatic myositis, polymyositis and dermatomyosis. We describe here a case of lung cancer revealed by dermatomyositis appearing by a diffuse and intense uptake of 99mTc-HMDP in the whole-body scintigraphy. Case report A 49 year old was hospitalized for muscle weakness over the bilateral proximal extremities with heliotrope cutaneous rash. Physical examination revealed symetrical upper and lower member tenderness. The extensor muscles of the arms were more affected than the flexors. Distal strength was a little more maintained. Blood analysis at admission showed an elevated creatine kinase (CK). A skin biopsy sample reveals an interface dermatitis with a vacuolar changes of the columnar epithelium and lymphocytic inflammatory infiltrates at the dermal-epidermal junction.. Muscle biopsy samples reveal perivascular and interfascicular inflammatory infiltrates with adjoining groups of muscle fiber degeneration/regeneration. Chest radiography obtained at the time of diagnosis revealed an opacity in the upper lobe of the left lung (Figure 1).