A Corrugated Plaque on the Abdominal Wall

Abstract

A 66-year-old woman was seen for examination of an erythematous, bumpy plaque of 10 months' duration on the lower abdominal wall. Findings from the physical examination showed a triangular-shaped, indurated, and erythematous plaque with irregular borders in the hypogastric area (Fig 1). The surface was corrugated, and the follicular openings were exaggerated (Fig 2). Other cutaneous manifestations included facial erythema with a violaceous hue, especially marked on the upper eyelids, and bluish-red plaques on the dorsa of the fingers.In the 2 years before her presentation, the patient experienced a 10-kg weight loss, malaise, and weakness of the limb muscles. Laboratory investigations demonstrated the following values or results: erythrocyte sedimentation rate, 80 mm/h; creatine phosphokinase, 1036 U/L (normal, <175 U/L); lactate dehydrogenase, 820 U/L (normal, <430 U/L); aspartate aminotransaminase, 178 U/L (normal, <37 U/L); antinuclear antibodies, positive (titer, 1/80 [homogeneous pattern]); anti-ssDNA, positive (429 U/mL); and anti-nDNA, anti-RNP, anti-Sm, anti-Ro, anti-La, anti-Scl-70, anti-centromere, rheumatoid factor, cir¬ culating immune complexes, and complement levels, normal or negative. The clinical manifestations and the laboratory results were consistent with a diagno¬ sis of dermatomyositis, and a biopsy of a deltoid muscle was performed. The histopathologic study of this muscle specimen showed fragmented fibers and a variable degeneration of the muscle bundles with edema and inflammatory cells, mainly lymphocytes. Electromyography showed unusual irritability on in¬ sertion of the electrodes, presence of pseudomyotonic discharges, and positive sharp waves. A diagnosis of dermatomyositis was made; we began an exhaustive search for internal malignancy. No abnormalities were noted on breast exploration; a chest roentgeno¬ gram; an upper gastrointestinal tract roentgenographic series; a barium sulfate enema; and ultra¬ sonic examinations of liver, spleen, pancreas, kidneys, uterus, ovaries, urinary bladder, and the retroperitoneal space. Radioimmunoassay determinations of afetoprotein, carcinoembryonic antigen, tissue polipeptidic antigen, and carbohydrate antigens showed normal levels of these circulating tumor-associated antigens in serum samples.A skin biopsy specimen was obtained from the ab¬ dominal plaque, and the histopathologic findings are demonstrated in Figs 3 and 4 (alcian blue stain).

Dermatomyositis and mucinosis

“…Clinically evident forms of mucinosis associated with dermatomyositis have been rarely described, including one patient with Hashimoto thyroiditis and scleromyxedema, 12 a case with lichen myxedematosus, 13 a case with a corrugated plaque on the abdominal wall, 14 a case of papular mucinosis, 15 a case of reticular erythematous mucinosis, 16 and two cases with plaque‐like cutaneous mucinosis as the presenting symptom of dermatomyositis 17 …”

Scleromyxedema (lichen myxedematosus) associated with dermatomyositis

“…Secondly, mucin deposits can be considered as a histological criterion in DM 11,12 . However, this mucinosis is rarely clinically detectable; 13–15 it is typically a secondary mucinosis whose pathogenesis remains unclear but probably involves fibroblast stimulation by cytokines such as interleukin‐1 or interferon 16,17 . Thirdly, scleromyxedema can be associated with a myopathy that differs from DM 2–5 .…”

Dermatomyositis presenting as plaque‐like mucinosis

“…Kock et al 8 reported a 66-year-old woman with a bumpy plaque of 10 months duration on the lower abdominal wall along with facial erythema and bluish-red plaques on the dorsa of the fingers. 9 Myositis preceded the cutaneous signs by 2 years. The diagnosis of dermatomyositis was confirmed, and histology of the abdominal lesion showed abundant deposits of dermal mucin.…”

“…The diagnosis of dermatomyositis was confirmed, and histology of the abdominal lesion showed abundant deposits of dermal mucin. 9 The pathogenesis of increased mucin production (especially hyaluronic acid) by the fibroblasts is still unknown. In primary cutaneous mucinosis (e.g.…”