Case report :
A 36-year-old male presented to our dermatological department for
painful swelling of the sole of the right foot. The lesion started 6
years ago and the patient had no history of trauma. It progressively
increased in size and caused a limp when walking. The clinical
examination revealed a 5*3 cm single tumor of the right foot, mobile,
not painful on palpation with normal overlying skin (Figure 1). The
lymph nodes were free. Face and profile radiographs of the foot were
normal. The ultrasound showed a circumscribed mass measuring 48*30*26
mm, non-vascularized with heterogeneous tissue that was isoechoic in
comparison to the fat tissue. Magnetic resonance imaging demonstrated
that it was a multi-lobulated lesion with a fat signal on all sequences.
This tumor was located in the extra aponeurotic subcutaneous soft tissue
of the sole without deep extension (Figure 2). The Tumor was clinically
diagnosed as lipoma. The lesion was excised with the removal of
lobulated lipomatous mass weighing 32 g and measuring 5*3*3 cm. It was
encapsulated with a well-limited surface. Histological examination of
the tumor confirmed a well-circumscribed lipomatous mass composed of
proliferating of mature adipocytes arranged in lobules separated by
fibrous septa. There were rare places of cellular fibrous spans with
spindle cells arranged in bundles. There was no cell atypia, lipoblasts,
nor mitotic figures (Figure 3A). Immunohistochemical staining of spindle
cells was strongly positive for CD 34, while negative for S-100 protein
(Figure 3B). These findings were consistent with the diagnosis of benign
Spindle cell lipoma.