Vulvar granular cell tumor (Abrikossoff’s tumor) – Case report

Received on: 28/02/2011
Approved on: 18/06/2011

This study was carried out at the
Dermatology Department of the Faculdade
de Medicina do ABC (FMABC) - Santo André
(SP), Brazil, at Hospital Mário Covas.

Conflicts of interests: None
Financial support: None

Abstract

Introduction: The granular cell tumor was first described by Abrikossoff in 1926. It is a benign, uncommon neoplasia, most frequently found on the tongue. It occurs in the vulva in 5 to 6% of cases. Its histogenesis is not known for sure, but is probably linked to Schawann cells. It is treated surgically, with a good prognosis. The tumors may recur, and some may become malignant according to the literature. The authors describe a case of a vulvar nodule with a histopathologic diagnosis of granular cell tumor, which was successfully treated with surgery.

Keywords: VULVA, VULVAR DISEASES, VULVAR NEOPLASMS, GRANULOSA CELL TUMOR

INTRODUCTION

A granular cell tumor was first described by Abrikossoff in 1926, in a patient with a lesion on the tongue. 1 It is a neoplasia of uncertain histogenesis, probably linked to Schwann cells, with a typical histological appearance, presenting polygonal cells with the characteristic granular cytoplasm. 2,3 The most frequent site is the tongue, but they can occur in the oral mucous membrane, gastrointestinal tract, biliary tract, musculoskeletal system, sali- vary glands, breasts, prostate, pituitary gland and, with lower fre- quency, in the vulvar 4 and clitoridian 2 region. Granular cell tumors affect more blacks, prevailing in women aged 20 to 50. 3,4

They usually appear as a single, asymptomatic or painful nodule, with a color that varies from brownish to red, or cov- ered by normal skin. Cases with multiple lesions have been reported. 4

The recommended treatment is the surgical exeresis of the lesion. The prognosis is usually good, with cases of recurrence probably correlated to the incomplete removal of the tumor. These tumors rarely become malignant. 2 The authors report a case of Abrikossoff tumor (granular cell tumor) with uncom- mon features in the vulva, which was treated surgically without reincidence after 36 months.

CASE REPORT

A 48-year-old black female patient, originally from Santo André, São Paulo, Brazil was referred to the Gynaecology Service presenting a brownish, painless nodule approximately 2 cm in diameter. The nodule was movable in relation to deep- er planes, as it was located in the left labium majus, close to the clitoris (Figure 1). A biopsy was carried out using a 3 mm der- matologic punch, with a histopathologic diagnosis of granular cell tumor (Abrikossoff tumor).

The excision and suture of the lesion was carried out under infiltrative local anesthesia (lidocaine chlorhydrate with norepinephrine 1:50,000). The macroscopic analysis of the excised tissue showed a whitish proliferation of poorly defined margins (Figure 2). The histopathologic examination, carried out using hematoxylin-eosin (HE) staining, revealed an epider- mis with pseudoepitheliomatous hyperplasia, both in the super- ficial and deep dermis, and cellular proliferation with the appearance of small blocks, permeated by thin bands of dense conjunctive tissue (Figure 3). The proliferated cells present wide cytoplasm containing thin, PAS-positive granulation. The nuclei were centered and without atypias. The immunohistochemistry was positive for S-100 and enolase, both with a cytoplasmic pat- tern. Results were negative for CEA and HMB-45. There was no recurrence in the follow-up period of 36 months after sur- gery (Figure 4).

DISCUSSION

Granular cell tumors, also known as Abrikossoff tumors or granular cell myoblastomas, are uncommon and are found in several sites, most frequently on the tongue. They can occur on the vulva, mainly in the labia majora. 5 Only 5-6% of the cases reviewed in the medical literature occurred in the vulvar region. 6

The histogenesis of granular cell tumors is uncertain. It is believed that the tumors are caused by alterations in the cellular metabolism of Schwann cells – a hypothesis that is reinforced by the constant presence of the S-100 protein in the immunohis- tochemistry, which appears with cytoplasmic pattern positivity, 3 which has also occurred in the present case.

Microscopically, polygonal cells with small nuclei and cytoplasms are observed, which contain abundant eosinophilic granular substance. Other neoplasias, such as angiosarcoma, leiomyoma, dermatofibrosarcoma protuberans and basal cell car- cinoma, can also present granular cytoplasm, however they pres- ent other histological and immunohistochemical characteristics that distinguish them from Abrikossoff tumors. 2

Granular cell tumors clinically present as an asymptomatic nodule, painful or slightly pruriginous, normochromic, brown- ish or erythematous hyperchromic, varying from 0.5-3.0 cm in diameter. 7 The differential diagnosis in the vulvar case includes Bartholin gland cysts, lipoma, papilloma, hidradenoma and fibroma. 8 Malignant transformation can occur in 1-2% of cases. 9

Clinical diagnosis is very difficult, especially in the vulvar region, due to the rarity of this lesion and its capacity to mimic other pathologies that are more frequently found in that loca- tion; in general, it requires a histological diagnosis.

The recommended treatment is the surgical exeresis of the lesion. Local recurrence of the lesion can occur in 15% of cases if the excision is incomplete. 10 In the present case, the lesion was completely removed, without recurrence after 36 months of fol- low-up.

References

1 . Abrikossoff AL. Uber Myome, aus gehend von der quergestreifter willknerilicher Muskulatur. Virchows Arch A Pathol Anat Histopathol. 1926; 260:215-33.

2 . Ortiz-Hidalgo C, de La Vega G. Granular cell tumor (Abrikossoff tumor) of the clitoris. Int J Dermatol. 1997; 36(12):935-7.

3 . Junquera L, de Vicente J, Losa JL.Granular cell tumor: an immunohisto chemical study. Br J Oral Maxillofac Surg. 1997; 35(3):180-3.

4 . Apisarnthanarax P.Granular cell tumor: an analysis of 16 cases and review of literature. J Am Acad Dermatol. 1981; 5(2):171-82.

5 . Lieb SM, Gallousis S, Freedman H.Granular cell myoblastoma of the vulva.Gynecol Oncol. 1979; 8(1):12-20.

6 . Levavi H, Sabah G, Kaplan B,Tytiun Y, Braslavsky D, Gutman H.Granular cell tumor of the vulva: six new cases. Arch Gynecol Obstet. 2006; 273(4):246-9.

7 . Bologna JL, Jorizzo JL, Rapini RP. Neural and neuroendocrine neoplasms. In: Bologna JL, Jorizzo JL, Rapini RP, Editors. Dermatology. Philadelphia:Mosby; 2003. p.1843-59.

8 . Cohen Z, Kapuller V, Maor E, Mares AJ. Granular cell tumor (myoblas- toma) of the labia major: a rare benign tumor in childhood. J Pediatr Adolesc Gynecol. 1999; 12(3):155-6.

9 . Simone J, Schneider GT, Begneaud W, Harms K. Granular cell tumor of the vulva: literature review and case report. J La State Med Soc. 1996; 148(12):539-41.

10 . Becelli R, Perugini M, Gasparini G, Cassoni A, Fabiani F. Abrikossoff ''s tumor. J Craniofac Surg. 2001; 12(1):78-81.