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.