Case report
A 36-year-old Tunisian woman had been followed in our dermatology department for six years. She was referred to us for chronic prurigo. Laboratory testing revealed hypochromic microcytic anemia. Serum glucose, HBA1C and liver plasma tests were normal. Abdominal ultrasound was normal. She was treated with topical steroid intermittently with variable response. Since this episode, she has returned several times with polymorphous skin lesions such as papules, erythematosquamous and crusty plaques, vesicles, pustules and erosions accompanied by severe pruritus. At that time, we thought she had prurigo (Fig.1a), eczema (Fig.1b), insect bites (Fig.1c) or even drug eruption (Fig.1d).
The eruption was episodic with spontaneous exacerbations and remissions. The patient had no abdominal pain, gastrointestinal symptoms nor weight loss. Multiple skin biopsies were performed. They concluded to drug eruption, eczema, prurigo and erythema multiforme. During the course of the outbreaks, the patient developed angular cheilitis and gingivitis, a deep vein thrombosis in the leg, and psychological problems which affected her social and professional life. Six years later, she presented with acute abdominal and pelvic pain. Abdominal Computed Tomography (CT) was performed and hyperdense mass was confirmed on body-tail pancreatic of 15 cm in maximum diameter with mild degree of contrast enhancement. Removal of the tumour was indicated and the cutaneous lesions vanished one week after surgery. Pathology report indicated a tumor in the pancreatic alpha cells. Immunohistochemistry showed expression of glucagon and chromogranin A in tumor cells (diagnosis of glucagonoma). No metastases were detected.
Retrospectively, on reviewing the patient’s photos, in addition to the deceptive lesions, our patient presented a unique clinically and histologically typical episode in which we missed unfortunately the diagnosis. She had an annular-circinate, erythematous, scaly rash with areas of hyperpigmentation and skin sloughing, mainly involving the extremities, buttocks, and perineum (Fig.2a). The lesions were highly suggestive of NME. Skin biopsy revealed psoriasiform acanthosis and abrupt necrosis of the upper layers of stratum; whereas the lower half of epidermis appears viable, the detached necrolytic portion appears pale with pyknotic nuclei. Perivascular lymphocytic infiltration and scattered extravasated red blood cells were present in the upper dermis (Fig.2b).
The absence of diabetes and gastrointestinal symptoms led to misdiagnosis.
Two years after surgery, the patient presented with typical skin signs of NME (Fig.3) and diabetes. Magnetic resonance imaging (MRI) and abdominal CT were normal. We asked for a review of the MRI and CT scan because we were sure that the tumour had recurred. Two nodules were visualized on MRI: a retropancreatic nodule (13 mm) and a nodule opposite the tail of the pancreas (11 mm), with heterogeneous T2 signal, diffusum hypersignal, without intense arterial enhancement, homogeneous at both portal and late phases. The octreoscan didn’t show distant metastases. The patient was referred to surgery for surgical resection of the tumour.