Spindle Cell Rhabdomyosarcoma: A Brief Diagnostic Review and Differential Diagnosis

Abstract

Spindle cell rhabdomyosarcoma is a rare variant of embryonal rhabdomyosarcoma that has a predilection for young males and most commonly involves the paratesticular region followed by head and neck. Histopathology demonstrates elongated spindle cells with fusiform to cigar-shaped nuclei and indistinct eosinophilic cytoplasm arranged in fascicles or whorls. Although the tumor demonstrates increased cellularity and moderate atypia, the microscopic and architectural patterns can allow this tumor to be confused with multiple entities, such as leiomyosarcoma, spindle cell carcinoma, desmoplastic melanoma, or fibrosarcoma, with important therapeutic implications. Immunohistochemical workup demonstrates sarcomeric differentiation with reactivity for desmin, myogenin, and MyoD1 markers. Compared with other subtypes, the spindle cell variant in children is associated with a favorable outcome; however, in the adult population there does not appear to be any prognostic advantage.

Spindle Cell Rhabdomyosarcoma Masquerading as Pseudo-Tumour of the Orbit

“…The cells exhibit eccentric nuclei and bright cytoplasmic eosinophilia, occasionally exhibiting cross striations. [8] features of which is seen in our case report. It shows loss of heterozygosity for multiple loci at chromosome 11p15.5.…”

“…[6,7] Embryonal Rhabdomyosarcoma is the most common variant, commonly seen in children less than 10 years. [7,8] Microscopically, uniform cellular proliferation of elongated spindle cells arrayed in fascicles and whorls are seen. The cells exhibit eccentric nuclei and bright cytoplasmic eosinophilia, occasionally exhibiting cross striations.…”

“…[7] Alveolar rhabdomyosarcoma comprise of nests of primitive cells that appear to float in the middle of alveolar spaces with a fibrovascular septa, which outline the cell clusters. [8] Pleomorphic rhabdomyosarcoma are high-grade sarcomas comprising of irregular, hyperchromatic nuclei and numerous mitoses. [8,9] Botryoid variant consists of cells varying from primitive small cells to cells with extensive myoblastic differentiation.…”

“…[8] Pleomorphic rhabdomyosarcoma are high-grade sarcomas comprising of irregular, hyperchromatic nuclei and numerous mitoses. [8,9] Botryoid variant consists of cells varying from primitive small cells to cells with extensive myoblastic differentiation. The stroma is loosely cellular with a myxoid appearance including a hypocellular zone that separates the surface epithelium from the underlying cambium layer.…”

“…[7] The rare variants of rhabdomyosarcoma include sclerosing variant and clear cell variant. [8] In children, the primary lesions most commonly encountered are Ewing's sarcoma, neuroblastoma and lymphoma. [8] Immunohistochemistry plays an important role in diagnosis and distinction of various types of rhabdomyosarcoma.…”