title: A case report of a rare intramuscular granular cell tumor.
abstract: BACKGROUND
  Granular cell tumors (GCTs) were firstly described by Weber in 1854 and 70 years later by Abrikossoff and classified as benign tumors. Originally considered muscle tumors, they have been identified as neural lesions, due to their close association with nerve and to their immunohystochemical characteristics. GCTs are uncommon tumors and they may arise in any part of the body; they have been mainly observed in tongue, chest wall and upper extremities; less frequent sites are larynx, gastrointestinal tract, breast, pituitary stalk and the female anogenital region. Here we report a case of GCT showing an uncommon localization such as the upper third of the right rectus muscle of the abdominal wall.
  
  
  METHODS
  A 45 year-old woman of Caucasian origin presented to the surgeon with a 6-month history of light pain in the upper third of the abdominal wall. Radiological exams (Ultrasonography, Computed Tomography and Contrast magnetic resonance imaging) showed a localized in the right rectus abdominis muscle. After excision, histological and immunohystochemical analysis, with the support of electron microscopy, allowed making diagnosis of granular cell tumor.
  
  
  CONCLUSIONS
  After fist description by Abrikosoff in 1926 of GCT like mesenchymal tumor of unknown origin, in recent years immunohystochemical techniques definitely demonstrated the histogenetic derivation of GCT from Schwann cells. Granular cell tumors are rare, small, slow-growing, solitary and painless subcutaneous nodules which behave in a benign fashion, but can have a tendency to recur; in rare cases they can metastasize, when they became malignant; there are some clinical and histological criteria to suspect the malignance of this tumor.
  
  
  CONCLUSIONS
  It is important that clinicians, radiologists and pathologists are aware of the clinical presentation and histopathology of GCT for appropriate management, counselling and follow-up. In our case we had a complete radiological, morphological and immunohystochemical characterization of the lesion and a definitive diagnosis of benignity confirmed by electron microscopy.
authors.affiliation: Department of Medico-Surgical Sciences and Biotechnologies, Histology Unit, Sapienza University of Rome, ICOT Hospital, Latina, Italy. natale.porta@alice.it.
authors.forename: Natale
authors.initials: N
authors.lastname: Porta
authors.affiliation: Surgical Unit, Casa di Cura "Cappellani Giomi", Messina, Italy. gmrromeo@virgilio.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Mazzitelli
authors.affiliation: Department of Medico-Surgical Sciences and Biotechnologies, Histology Unit, Sapienza University of Rome, ICOT Hospital, Latina, Italy. cacciotti.jessica@libero.it.
authors.forename: Jessica
authors.initials: J
authors.lastname: Cacciotti
authors.affiliation: Department of Medico-Surgical Sciences and Biotechnologies, Histology Unit, Sapienza University of Rome, ICOT Hospital, Latina, Italy. mirco.cirenza@alice.it.
authors.forename: Mirko
authors.initials: M
authors.lastname: Cirenza
authors.affiliation: Pathology Unit, Casa di Cura "Cappellani Giomi", Messina, Italy. agatalabate74@gmail.com.
authors.forename: Agata
authors.initials: A
authors.lastname: Labate
authors.affiliation: Surgical Unit, Casa di Cura "Cappellani Giomi", Messina, Italy. mgloschiavo@libero.it.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Lo Schiavo
authors.affiliation: Department of Radiological, Oncological and Pathological Sciences, Radiology Unit, Sapienza University of Rome, ICOT Hospital, Latina, Italy. andrea.laghi@uniroma1.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Laghi
authors.affiliation: Department of Medico-Surgical Sciences and Biotechnologies, Histology Unit, Sapienza University of Rome, ICOT Hospital, Latina, Italy. vincenzo.petrozza@uniroma1.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Petrozza
authors.affiliation: Department of Medico-Surgical Sciences and Biotechnologies, Histology Unit, Sapienza University of Rome, ICOT Hospital, Latina, Italy. carlo.dellarocca@uniroma1.it.
authors.forename: Carlo
authors.initials: C
authors.lastname: Della Rocca
mesh_terms: D000009:Abdominal Muscles / Q000473:pathology*; D034861:Abdominal Wall / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D016586:Granular Cell Tumor / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor