A Rare Case of a Metastatic Malignant Abrikossoff Tumor

Abrikossoff tumor, also called granular cell tumor (GCT), is a neoplasm of the soft tissues which is most commonly a solitary, painless, and benign tumor. However, 2% of Abrikossoff tumors can be malignant. We report here the case of a 75-year-old male who presented a local recurrence of Abrikossoff tumor of the left thigh. The anatomopathological analysis concluded to a malignant GCT, and the F-18 fluorodeoxyglucose positron emission tomography showed multiple lesions in the lymph nodes and bones. The potential conversion to malignancy should alert practitioners because of the extremely poor prognosis. The diagnosis of malignant granular cell tumor should be based on a bundle of clinical and histological features and not solely on histologic features because of the challenging distinction between malignant and benign tumors due to the lack of well-defined criteria for the diagnosis of malignancy. Large size and recurrence are the most important clinical features predicting malignant behavior. Patients with a history of Abrikossoff tumor should be followed closely to monitor recurrence and malignant transformation. The apparent originality of our observation – which could lie in the evolution of a GCT tumor, initially considered as benign, to a malignant form – has to be challenged regarding the issue of classifying some cases according to the classical “benign” and “malignant” dichotomy.

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.

Comprehensive Genomic Characterization of A Case of Granular Cell Tumor of the Posterior Pituitary Gland: A Case Report

Granular cell tumors of the pituitary belong to a rare family of neoplasms, arising from the posterior pituitary gland. Although considered benign, they may cause significant morbidity and residual disease after resection can lead to poor clinical outcomes. Currently, there is no known medical therapy for any posterior pituitary gland tumor, in part due to sparse molecular characterization of these lesions. We report data from whole exome sequencing of a case of granular cell tumor of the pituitary, performed under an institutional review board approved protocol. A 77 year-old female underwent resection of an incidentally diagnosed pituitary mass that was causing radiographic compression of the optic nerves with a subclinical temporal field defect and central hypothyroidism. The pathology of the resected specimen demonstrated a granular cell tumor of the posterior pituitary gland. Whole-exome sequencing revealed mutations predicted to be deleterious in key oncogenes, SETD2 and PAX8, both of which have been described in other cancers and could potentially be amenable to targeted therapies with existing approved drugs, including immune checkpoint inhibitors and histone deacetylase inhibitors, respectively. To our knowledge, this is the first comprehensive genomic characterization of granular cell tumor of the posterior pituitary gland. We report mutations in oncogenes predicted to be deleterious and reported in other cancers with potential for therapeutic targeting with existing pharmacologic agents. These data provide new insights into the molecular pathogenesis of GCT of the pituitary and may warrant further investigation.