Introduction

Abrikossoff’s tumour (AT) is a rare benign soft tissue neoplasm of unknown aetiology (1), first described in a patient with a lesion on the tongue by Abrikossoff (2).

It could be also called Granular cell tumour (GCT) or Myoblastoma (My), in fact, the denomination of this tumour depends on its real histogenesis, which remains unsettled, since different derivations have been postulated by various authors, including fibroblasts, myoblasts, undifferentiated mesenchymal cells, Schwann cells, histiocytes and neural cells (3, 4).

Granular cell tumours can affect any organ or region of the body. Most GCTs occur in the head and neck region, especially in the tongue, cheek mucosa, and palate (5).

It can occur in patients of any age, although it is more common between the fourth and the sixth decades of life, being rare in children, although cases have been described in the literature even at a young age (6). Abrikossoff’s tumour is two or three times more common in women than in men. Black patients are more prevalent than white (6, 7).

Recently, most of the lingual lesions have been reported to occur on the lateral border of the dorsum of the tongue (8). Therefore, the purpose of this paper was to report a case of granular cell tumour of the tongue, in a 36-year-old female patient, which occurred on the dorsum of the tongue, together with a brief review of recent literature.

Case Report

A 36-year-old Dominican was referred to the Department of Oral and Maxillofacial Surgery in Policlinico Federico II, Naples, Italy with a painless lingual swelling, incidentally discovered five months earlier. She did not complain of bleeding, and no significant clinical data (diabetes, hypertension, allergies) were present in her clinical history; our patient had always been well and she referred to a healthy lifestyle; laboratory investigations were mostly normal.

The clinical examination showed a well circumscribed lesion and sessile nodule, 17 mm in diameter. The mass was located just beneath the mucosa of the lateral border of the dorsum of the tongue, and had a fibroelastic consistency which was not tender to palpation. The overlying non-ulcerated mucosa was intact (Figure 1).

Figure 1 Well delimited nodular lesion located on the dorsum of the tongue

An excisional biopsy was performed based on a differential diagnosis of a traumatic fibroma of the tongue, lipoma, and Abrikossoff’s tumour (Figure 2).

Figure 2 Excised lesion measuring about 1.7 cm across its major diameter.

Histopathological findings revealed a neoplasia constituted of large cells with highly granular cytoplasm. The lesion involved entirely the dermis showing a pseudo-infiltrative pattern, dissecting the muscle fibres. For this reason, it was consistent with a granular cell tumour. The lesion was contained within the limits of excision with a minimum distance of about 0.3 mm from the deep structures (Figure 3).

Figure 3 The lesion involves entirely the dermis and shows a pseudo-infiltrative pattern, dissecting the muscle fibres. (A, B: hematoxilyn-eosin, 200X and 250X, respectively).

The postoperative course was uneventful. The patient was first examined one week later and then, respectively, 3, 6, and 12 months after the surgical excision; so far, no sign of recurrence has been noted.

Discussion

In cases of tongue lesions, it is necessary to take utmost care since the high vascularization of this organ can lead to a rapid transportation of circulating tumour cells. In particular, we must always make a differential diagnosis, as in our case where the diagnosis of Abrikossoff’s tumour was not certain. Features such as consistency, colour and the possible definition of lesion margins upon palpation may facilitate the establishment of diagnostic hypotheses (5, 9).

Histologically, GCTs are characterized by the proliferation of large polygonal neoplastic cells with cytoplasmic granules, eosinophilic cytoplasm, a small and eccentrically located nucleus, and undefined cytoplasmic limits (10). In some cases, the epithelium that covers the tumour exhibits pseudoepitheliomatous hyperplasia (11). Histochemistry and immunohistochemistry can confirm the diagnosis of GCT when S100-positive cells containing pAS-positive and Cd68-reactive granules are seen. Adverse immunohistochemical prognostic factors of GCTs include Ki67-index > 10% and p53 immunoreactivity, in the present case we did not find any histological criteria of malignancy (4, 12).

Although Abrikossoff’s tumour is an uncommon benign neoplasm, cases of malignant GCT have been reported in the literature, including patients with more than one histological type of malignant GCT. In view of this malignant potential, the tumour should be submitted to thorough histopathological analysis. Data regarding the tumour size, symptoms, rapid progression, invasion of adjacent structures, and the presence of regional and distant metastases are of fundamental importance for the histopathological diagnosis of benign or malignant GCT (9).

Surgical excision with a safety margin is the treatment of choice for Abrikossoff’s tumour, although this is not always possible because the tumour lacks a capsule, a condition histologically demonstrated by an undefined cell margin (13). An excisional biopsy was also the treatment of choice in the present case. Angiero et al. had also described some GCT tumour cases treated with laser but only when it is small in size (14).

In conclusion, the association of histological and clinical aspects with the immunoprofile is essential to establishing the correct diagnosis of this lesion.

After surgical excision, only further reports of the GCT along with the regular follow up reports will help us in understanding and predicting the nature of this tumour.