First described by Abrikossoff as myoblastenmyome tumor [3]; GCT said to be arising from Schwann cells, though this neoplasia can be found at any anatomic site, the most common ones are the head and neck region; specifically in the 2/3 of the oral tongue [2.3], followed by skin and subcutaneous tissues, breast, respiratory and gastrointestinal tracts [1.4].
What account for 0.5% of all soft tissue tumors, have variable age, sex and ethnicity predilection; depending on the localization; the larynx locating have a predilection for male and the same distribution between caucasians and blacks [5.6]; the few hypopharynx cases reported however, have a preponderance for females and black ethnicity and wide age range from 29 to 61 years old [1.2.7.8].
Nonspecific symptoms have been reported in relation with hypopharynx sites of GCT, such as globus pharyngeus, dysphagia, associated or not with lenient dyspnea and hoarseness or even dysphoniabut asymptomatic tumor have also been documented [1.2.9.10].
GCT usually displays as small, smooth, submucosal lesion, unencapsulated, but also polypoid or sessile and pedunculated [1]. The submucosal appearebce explains the differential diagnosis such as angiomyoma, synovial sarcoma and salivary gland tumors [1.2].
A complete ENT and panendoscopy examination is mandatory; as the tumor may present as numourous or solitary lesion, the first variant can be either as synchronous or metachronous lesions [1.2.7.8]. Speaking of variant; GCT can be either malignant, begin or atypical determined by Fanburg-Smith criteria that includes: tumor cell spindling, necrosis, increased rate of mitosis with more than 2 mitosis per 10 hpf, vesicular nuclei with large nucleoli, pleomorphism and a high nuclear to cystoplasmic ratio. Two criteria define atypical GCT (aGCT), three or more indicate mGCT and none of the criteria or focal pleomorphism describe the 98% of GCTs; the benign ones [1.2.11]. To note that; the first group have metastatic tendencies in 50% of the cases, in regional lymph nodes, bone or lung [11].
Microscopically GCTs are polymorphic with a large acidophilic cytoplasm. Positive staining for S-100 protein and ubiquitin carboxyl-terminal hydrolase confirms neuroectodermal origin [1.2.8].
GCT is shown in CT imaging as a solid mass with homogenous enhancement on contrast and portrayed as hypo intense homogenous tumor on contrast enhanced T1 sequence MRI [1.2]
The standard and recommended treatment is wide surgical resection with preferential for the endoscopic approach as Piazza et al [1] report a successful excision of hypopharynx GCT in two cases by endoscopic co2 laser [1.2]. Lack et al [3] also delineated 8% recurrence rate following the treatment of choice as the surgical margin were invaded, though numeours authors reported incomplete resection of the tumor without any reccurence in thelong follow-up [1.4].