Granular Cell Tumor of Cecum: A Common Tumor in a Rare Site with Diagnostic Challenge

Retinal granular cell tumor: a case report

Background

To report a rare case of granular cell tumor invading the retina.

Case presentation

A 56-year-old female complained of blurred vision for 2 weeks in her left eye. An irregular-shaped retinal mass in the inferonasal and extending to the optic disc accompanied by dense exudation and extensive serous retinal detachment was observed. Several intravitreal bevacizumab injections were ineffective for stabilizing retinal exudation and intraocular pressure (IOP). Vitrectomy was performed to re-attach the retina and obtain a tumor biopsy specimen. Histopathological analysis revealed that the intraocular mass was a granular cell tumor. Immunohistochemical studies demonstrated that the tumor was positive for S100 and CD68, focal positive for neurofilaments, but negative for ERG and HMB-45. Local recurrence and distant metastasis were not found, but visual acuity had worsened to no light perception at the last visit due to uncontrolled intraocular pressure and retinal exudation after the surgery.

Conclusions

Granular cell tumor is a rare benign neoplasm, but it can lead to devastating visual loss if it invades the retina adjacent to the optic nerve head.

Benign Granular Cell Tumor of the Cecum

Granular cell tumors (GCT) are usually benign, soft tissue tumors that are mostly found in the oral cavity, skin, and subcutaneous tissue. GCTs in the gastrointestinal (GI) tract are mainly located in the esophagus. A 63-year-old male was referred to the gastroenterology clinic for a major complaint of six months of painless rectal bleeding. Laboratory results showed mild macrocytic anemia. He denied any prior colonoscopies and hence, a lower endoscopic procedure was done. The colonoscopy showed multiple polyps, one of them located at the cecum. The cecal polyp showed polygonal cells with abundant eosinophilic infiltration and S100 stain positive. This confirmed a diagnosis of GCT. GCTs are thought to be derived from the neural tissue (Schwann cells). This entity is usually asymptomatic; however, tumors located at the lower GI tract can present with hematochezia. Only 2% of GCTs follow a malignant course, with associated poor prognosis.  This case is being presented because of its asymptomatic nature. It is important to monitor these lesions in order to recognize early signs/symptoms concerning for malignancy.

Cutaneous granular cell tumor clinically mimicking ectopic breast diagnosed on fine needle aspiration cytology

Granular cell tumor (GCT) is a rare benign neoplasm of Schwannian origin which accounts of 0.5% of soft tissue tumors. Although the most common site for GCT is tongue, it can occur at any site. GCT presenting as cutaneous nodule is rare, however cases have been reported in literature. We hereby document a case of 30 year female with a hyper-pigmented cutaneous nodule of anterior chest wall on the milk-line mimicking as an ectopic breast, diagnosed as GCT on fine needle aspiration cytology. We also add a note on the differential diagnoses of GCT with differentiating cytological features to emphasize on the correct diagnosis of GCT pre-operatively.