Journal of Genital System & DisordersISSN: 2325-9728

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Case Report, J Genit Syst Disor Vol: 5 Issue: 4

Granular Cell Tumors are Very Rare but Important Vulvar Masses that should not be Overlooked

Al Naimi A1*, Schulze F2, Schmidt-Fittschen M1 and Bahlmann F1
1Department of Obstetrics and Gynecology, Buerger Hospital, Frankfurt, Germany
2Dr. Senckenberg Institute for Pathology, University Hospital, Frankfurt, Germany
Corresponding author : Ammar Al Naimi, M.B.Ch.B., MSc., Dr. med.,
Department of Obstetrics and Gynecology, Buergerhospital Frankfurt, Germany
Tel: +49-69-1500-1509
Fax: +49691500400
Received: April 25, 2016 Accepted: July 26, 2016 Published: August 02, 2016
Citation: Al Naimi A, Schulze F, Schmidt-Fittschen M, Bahlmann F (2016) Granular Cell Tumors are Very Rare but Important Vulvar Masses that should not be Overlooked. J Genit Syst Disor 5:4. doi: 10.4172/2325-9728.1000161


Granular cell tumors are uncommon neoplasms of neural origins affecting the submucosal and subcutaneous tissue in the tongue, neck, head, and genitals. Vulvar tumors represent about 15% of the cases and present as solitary painless swellings with or without accompanying local manifestations. It is more common in Afro- American women in their fourth to fifth decade.

They are predominantly benign tumors with malignant variants in 1-3% of cases. Malignant forms are aggressive, therapy-resistant, and can metastasize. Wide excision with clear margins is the recommended curative treatment. More than 33% of excisions have positive margins, increasing the risk for local recurrence from 2% to about 20%. The combined risk of recurrence and malignant transformation is a reason for recommending wide re-excision in cases with positive margins. We recommend a preoperative biopsy for every solid vulvar lump in order not to miss such a rare diagnosis and to correctly plan treatment.

Keywords: Case report; Granular cell tumor; Vulva; Vulvar masses; Vulvar neoplasm; Vulvar tumor


Case report; Granular cell tumor; Vulva; Vulvar masses; Vulvar neoplasm; Vulvar tumor


Abrikossoff first described a granular cell tumor (GCT), which was originally reported by Virchow [1], as granular cell myoblastoma of the tongue back in 1926 [2]. The immunohistochemical characteristics of GCTs illustrated their derivation from Schwann cells, thus their origin from the neural sheath [3].
GCTs are rare, usually benign tumors affecting the submucosal and subcutaneous tissue throughout the body, but mainly of the tongue, neck, breast and vulva [4]. GCTs predominantly affect Afro- American women with a peak incidence in the fourth to fifth decade [5].
Vulvar involvement is described in 7-16% of GCT cases, mainly as solitary benign tumors with malignancy in only 2% and multiple lesions in 25% [6]. We report a new case of vulvar GCT to add to the fewer than 200 cases in published literature.

Case Report

A 64-years old white female presented with a one-year history of a painless growth on her vulva. Examination revealed a 2 cm × 2 cm, smooth, solid, mobile, indolent tumor in the upper third of the labia majora, located at 10 o’clock of the vulva with echogenicity on ultrasound examination. The mass was not associated with regional lymphadenopathy, discoloration or ulceration. The patient had a known history of postmenopausal recurrent lipomas throughout the entire body with several surgical excisions, positive family history for malignant tumors with more than 9 individuals with stomach-, breast-, prostate- and lungcancer, and two siblings with lipomas.
Due to suspicion of vulvar lipoma a local excision was performed. The histological findings showed 1.2 cm GCT with irregular margins of proliferating cells with small nuclei and abundant eosinophilic granular cytoplasm. Immunohistochemically, the cells showed a very strong S100 protein staining, negative MNF116, negative estrogenand progesterone-receptors, weak Ki67 of less than 5%, and weak p53 in less than half of the tumor cells. The microscopic findings of GCT with different strains are shown in Figure 1.
Figure 1: The microscopic findings under 20x magnification for GCT with a) hematoxylin & Eosin stain b) Periodic acidic-Schiff stain c) S100 protein stain.
Due to involvement of the specimen’s margins, wide re-excision was performed to achieve a complete removal of the tumor. CT-scan showed normal results with no signs of metastasis, lymphadenopathy, or other tumors in the body. Bone scintigraphy excluded skeletal involvement. Regular annual follow-up is planned for ongoing surveillance.


GCTs are rare, soft tissue neoplasms of neural origins with involvement of variety of sites, but predominantly affecting the tongue (30%), neck, head, breast and vulva (15%) [5,7]. GCTs have male to female ratio of 1:4 [8], and have higher incidence in the fourth to fifth decade [5] even though a case in the neonatal period has been reported [8]. GCTs are usually solitary painless tumors with multiple lesions described in 7-29% of cases and mainly affecting the oral regions of Afro-American women [7]. Therefore, our case of a 64-year-old Caucasian female is an atypical GCT presentation.
Multiple GCTs or GCTs in younger age are reported to be associated with syndromes such as Noonan and LEOPARD syndromes [7]. A familiar link for GCT has also been suggested in families with soft tissue tumors [4]. Our case here shows positive family history for malignant tumors as well as soft tissue tumors (lipomas), thus supports the suggestion of investigating further familiar and genetic predisposition.
The differential diagnosis of vulvar GCT includes Bartholin’s cysts, fibromas, lipomas, epidermal cysts and papillomas and the definitive diagnosis is based on the typical histological findings [5]. GCTs are almost always misdiagnosed based on clinical presentation [8]. The fact that our patient had multiple lipomas already as well as the similarity in clinical presentation was the reason why we preoperatively misdiagnosed the tumor for a vulvar lipoma. This misdiagnosis was also the reason why wide excision was not initially performed and consequently the specimen’s margins were involved. Incomplete initial resection is associated with a 2-10% local recurrence [5]. A preoperative biopsy would have provided a definitive histological diagnosis. This in turn would have helped in planning the correct initial management with wide excision.
Even though GCTs are usually benign tumors, malignant forms are present in 1-3%. Necrosis, spindling, vesicular nuclei with large nucleoli, increased mitotic activity, high nuclear to cytoplasmic ratio, and pleomorphism are six criteria, that can be used to classify GCTs. Neoplasms meeting three or more of these criteria are considered histologically malignant and those that that display focal pleomorphism without meeting any of the other criteria are classified as benign [9].
Malignant GCTs can show local recurrence, lymphatic and hematogenous metastasis and resistance to both radioand chemotherapy. There is no successful treatment for the metastasized malignant variants and regimens with paclitaxel, carboplatin, cisplatin, and 5-fluoro-uracil have shown no effect. Therefore, aggressive surgical removal is recommended for all GCTs [10].
Tumors larger than 4-5cm, rapid growth, invasion of the adjacent tissues, older age at presentation, and local recurrence are suggested as prognostic factors for anticipating malignant changes in GCTs [11]. High Ki67 and p53 overexpression are also two indicators for atypical malignant GCT with worse prognosis [3]. Our patient had a benign tumor and only one poor-prognosis factor, which was her age at presentation.
The irregular margins of GCTs are due to the extension of the tumor cells beyond the macroscopic limits of the mass. This is one of the reasons why more than 33% of excisions have positive margins. Positive excision margins increase the risk for local recurrence from 2% to about 20% [5]. The combined risk for recurrence and malignant transformation is a reason for recommending wide re-excision in cases with primarily positive margins. Based on this recommendation, we performed a curative re-excision in our case.


Even though GCTs are rare, they represent an important differential diagnosis in vulvar tumors that should not be missed. Wide excision with clear margins is the recommended curative treatment with annual follow up. The 1-3 % risk for malignant transformation is small, but must be considered and discussed when counseling a patient with GCT given the aggressive and resistant pathophysiology. We recommend a preoperative biopsy for every solid vulvar lump in order to correctly plan initial treatment.


This work was supported by the Dr. Senckenbergische Stiftung, Frankfurt am Main.


We declare that we have no conflict of interest. Informed consent was obtained from the patient reported in this manuscript.


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