First of all, great scientist such as Liptak & Forrest (2013), come up with a great description of a soft tissue sarcomas whereby they define it as a heterogeneous form of tumours that mainly grow from the mesenchyme connective tissues .And there are several types of sarcomas which are arrange based on the similar pathologic appearance and clinical behaviour into a certain type or group (Liptak & Forrest (2013).
Jurdy et al, 2013 reveals that Embryonal rhabdomyosarcoma (ERMS) in generally is the most common high malignant soft tissue sarcoma that make about 4% of all paediatric malignancies, with 10% of all cases that mainly occurs in orbital cavity. Therefore, Orbital embryonal rhabdomyosarcoma is a highly malignant tumour that is composed of differentiated muscle cells and it mainly occurs in children’s that are under the age of 10 years especially males as compare to the females. The tumour can appear anywhere in the orbit, but it is more common to be detected in the retro bulbar region (Tang et al: 2018).
Normally patients that suffer from this particular condition tend to present with the proptosis that quickly grow over the weeks or present with the globe displacement, which is usually positioned downward and outward simply because most of these tumours are supero-nasal.
According to Jurdy et al, 2013 metastatic spread of this condition is uncommon, however if left untreated unfavourable reaction might occurs purely because orbital ERMS metastatic has a poor prognosis as compare to other localized disease .Orbital embryonal rhabdomyosarcoma (Orbital- RMS) condition has a tendency to metastasize to the lung, bone including bone marrow via haematogenous spread due to the fact eye lack the orbital lymphatics. In other cases Orbital –ERMS can also invade into the orbital bones where it will extend intracranial (Jurdy et al: 2013).
2.1 Clinical features:
As it was mentioned early that patient that suffer from Orbital ERMS they usually present with a very gradually and harmfully clinically symptoms which mainly involves a rapid proptosis or a displacement of the globe. Meaning that Orbital ERMS should be always suspected whenever patient start to present rapidly progressive unilateral exophthalmos (Karcioglu et al: 2004).
Over and above that, clinically presentation with a combination of the characteristic imaging features of the disease plays a huge role in helping to came up with the diagnosis of this particular condition as, myogenin is found to be the specific and sensitive marker of RMS (Singh et al:2017). Although most often this particular tumour arise denovo,a history of trauma may also help to came up with the diagnosis as ERMS may also associate with an unusually inherited disease such as Li-Fraumani syndrome, Neurofibromatosis typeII and multiple endocrine neoplastia type 2A (Singh et al:2017).
2.2 Morphological features:
At first RMS was considered as the type of tumour that arises from extra ocular muscles but through different types of studies it ended up concluded by saying it’s the type of tumour that develops from undifferentiated mesenchymal cells which they have the capacity to differentiate into striated muscle (Karcioglu et al :2004).
Rhabdomyosarcoma is classified into three different form based on the histopathological appearance where we have Embryonal,Alveolar,and Pleomorphic form but Embryonal is the most common form that mainly affect orbital cavity .
Embryonal RMS is predominantly composed of elongated pleomorphic tumour cells with centrally located hyper chromatic nucleus surrounded by a considerable amount of eosinophilic cytoplasm (Radzikowska et al: 2015).
Tumour cells of the ERMS differentiate along rhabdomyoblastic lines forming elongated, spindle cell types, longitudinal and cross striations which are mainly became visible when stain with phosphotungstic acid hematoxylin stain(Karcioglu et al: 2004) . The striations represent bundles of cytoplasmic actin and myosin filaments, and these banding pattern may be noticeable with the use of immunohistochemical markers such as actin and desmin (Karcioglu et al: 2004).