Exceptional case of a hemangioma-like rabdomyosarcoma in the hand's palm

Abstract

Rhabdomyosarcoma is a malignant tumor in children that might mimic a benign tumor, such as infantile hemangioma, particularly when detected early. Although rhabdomyosarcoma rarely occurs in the hand, its prognosis is generally poor, and successful treatment relies on a complete and radical surgical excision. We present a case of rhabdomyosarcoma located in the palm of an infant's hand, initially presenting clinical and radiological features suggestive of a vascular tumor. The resection of this mass was radical, and histological analysis and immunohistochemistry returned in favor of embryonic rhabdomyosarcoma. In similar cases recorded in the literature, the diagnosis may be first mistaken for that of a hemangioma, then confirmed by histology. This underlines the importance of a systematic anatomopathological examination of all tissues removed surgically.

Keywords: Child; Hand; Mass; Rhabdomyosarcoma; Vascular.

Fig. 1

The clinical aspect of rhabdomyosarcoma resembling a vascular mass.

Fig. 2

Magnetic resonance imaging of the right hand in non-fat-saturated T1-weighted coronal section without contrast injection (A), fat-saturated T1-weighted sequence in coronal section with contrast injection (B), fat-saturated T2-weighted sequence in sagittal section (C), and fat-saturated T2-weighted sequence in axial section (D) showing a well-defined, lobulated soft tissue mass with regular contours, located in the subcutaneous tissues of the thenar and hypothenar compartments of the right hand measuring 42 × 35 mm. The mass demonstrates exophytic growth with isointense T1 signal, hyperintense T2 signal, and intense homogeneous enhancement after contrast injection.

Fig. 3

Histological examination of the lesion reveals a dermal proliferation arranged mostly in sheets and large nodules (L: HES, x40). At higher magnification, tumor cells show a high nuclear to cytoplasmic ratio, with round and enlarged hyperchromatic nuclei, and scant cytoplasm (R: HES, x400).