[Subcutaneous annular granuloma: a differential diagnosis not to be forgotten in expansive lower leg (soft-tissue) lesions of young children].

PURPOSE: Expansive lower leg lesions in children include numerous, even malignant, entities. Good differential diagnostic knowledge is extremely important in those conditions in order to prevent unnecessary biopsy. Therefore, our own observations of a not particularly rare pseudotumorous soft-tissue disease are presented and the value of ultrasonography is emphasized.
MATERIALS AND METHODS: The imaging material (sonograms in all, MRI and radiograms in the first 4 and 3 patients, respectively) and the clinical charts of 7 young children (4 females, 3 males; aged 28 - 65 months) were analyzed retrospectively.
RESULTS: All lesions were pretibial, firm, indolent, non-movable, and without inflammatory signs. They had developed spontaneously. Laboratory tests were normal. Ultrasound demonstrated all lesions located subcutaneously, homogeneously echopoor with indistinct borders and only little increased perfusion. On MRI they presented with low signal in T 1, high in T 2 and marked contrast enhancement. No intraosseous changes or calcifications were found. Histological proof in the first 2 patients disclosed subcutaneous annular granuloma. Based on an identical clinical and sonographic initial presentation, biopsy and additional imaging were dispensed in the later patients. Their clinical course with only sonographic controls was as expected.
CONCLUSION: When dealing with expansive lower leg soft-tissue lesions in young children, the presented typical clinical and sonographic findings should give rise to consideration of the benign entity of subcutaneous annular granuloma and primary monitoring of those patients with only ultrasound. © Georg Thieme Verlag KG Stuttgart · New York.