Haider MY, Rahim M, Bashar NMK, Hossain MZ,
Islam SMJ.
Schwannoma is a benign nerve sheath tumor.
It was first identified by Virchow in 1908.
These tumors can emerge from any nerve covered
with a Schwann cell sheath, including the
cranial nerves (with the exception of the optic
and olfactory nerves), the spinal nerves, and
the autonomous nervous system (Harada H, Omura K
and Maeda A, 2001).
A 28-year-old male farmer presented with a
swelling at the right side of the base of tongue
extending into the oral tongue. It was
identified incidentally by his newly married
wife while he was yawning. It was asymptomatic.
The patient had no difficulty in chewing,
swallowing, or phonation and also no sensory or
taste abnormalities. The tongue movements were
normal.
Diagnosis of schwannoma should be considered
for a smooth, painless, firm swelling in the
tongue. A schwannoma of the tongue may grow
large enough before producing any symptom.
Around 25&endash;40% of schwannoma happen within
the head and neck region, and among these, 1-12%
occurs in the oral cavity, most regularly the
tongue or mouth floor. Schwannoma of the tongue
does not show any age or sex predisposition. It
usually presents as a painless lump in the
tongue, but when it grows larger than 3.0_cm, it
may produce dysphagia, pain, or discomfort and
change in the quality of voice. Here, the
authors report a case of large asymptomatic
schwannoma of the tongue in a 28-year-old male
patient and review the literature available
during the last 61 years.
Le schwannome est une tumeur bénigne
de la gaine nerveuse. Il a été
identifié pour la première fois
par Virchow en 1908. Ces tumeurs peuvent
émerger de tout nerf enveloppé
d'une cellule de Schwann, y compris les nerfs
crâniens (à l'exception des nerfs
optiques et olfactifs), les nerfs spinaux et le
système nerveux autonome (Harada H, Omura
K et Maeda A, 2001).
Un agriculteur de 28 ans présentait
un gonflement du côté droit de la
base de la langue s'étendant dans la
langue orale. Récemment marié, il
a été identifié par hasard
par sa femme alors qu'il bâillait. Il
était asymptomatique. Le patient n'avait
aucune difficulté à mâcher,
à avaler ou à parler et ne
présentait aucune anomalie sensorielle ou
gustative. Les mouvements de la langue
étaient normaux.
Le diagnostic de schwannome doit être
envisagé pour un gonflement lisse,
indolore et ferme de la langue. Un schwannome de
la langue peut devenir suffisamment gros avant
de produire un symptôme. Environ 25
à 40% des schwannomes surviennent dans la
région de la tête et du cou, et
parmi ceux-ci, 1 à 12% surviennent dans
la cavité buccale, le plus souvent la
langue ou le plancher buccal. Le schwannome de
la langue n'est pas lié à
l'âge ou au sexe. Il se présente
généralement sous la forme d'une
boule indolore dans la langue, mais lorsqu'il
dépasse 3,0 cm, il peut produire une
dysphagie, une douleur ou un inconfort et une
modification de la qualité de la voix.
Ici, les auteurs rapportent un cas de grand
schwannome asymptomatique de la langue chez un
patient de sexe masculin de 28 ans et passons en
revue la littérature disponible au cours
des 61 dernières années.
Introduction
Schwannoma is a benign nerve sheath tumor.
It was first identified by Virchow in 1908.
These tumors can emerge from any nerve covered
with a Schwann cell sheath, including the
cranial nerves (with the exception of the optic
and olfactory nerves), the spinal nerves, and
the autonomous nervous system [1]. When
the nerve of origin is small, it can be
difficult to demonstrate its connection with a
given tumor. On the other hand, if the site of
origin is a larger nerve, it is observed that
the nerve fibers are splayed over the outer side
of the capsule instead of being absorbed into
the tumor mass [2]. About 25&endash;45%
of all schwannomas occur in the head and neck
[3]. Around 1&endash;12% of these occur
intraorally [4, 5] with the tongue being
the most common site [5, 6]. Although
there are many case reports of tongue
schwannomas in the literature, after Hatziotis
et al. [6], there has been no
comprehensive review of the literature. We
present a case of tongue schwannoma and study
the literature available from the last 61 years
(1959&endash;2019).
Case Report
A 28-year-old male farmer presented with a
swelling at the right side of the base of tongue
extending into the oral tongue. It was
identified incidentally by his newly married
wife while he was yawning. It was asymptomatic.
The patient had no difficulty in chewing,
swallowing, or phonation and also no sensory or
taste abnormalities. The tongue movements were
normal.
On examination, there was an oval swelling
at the right side of base of the tongue
measuring about (Figure 1). The surface was
smooth, margin regular, and no discoloration or
distortion of tongue epithelium. It was
nontender, farm in consistency, and was not
fixed with underlying or overlying structures.
The remaining oral cavity examination was
normal; nasopharyngolaryngoscopy revealed no
abnormality in the adjacent areas. There was no
cervical lymph node enlargement. Clinically, it
appeared like a dermoid cyst or lipoma. MRI of
the tongue manifested hyperintense
well-circumscribed soft tissue mass in the right
half of the base of the tongue on T1/T2-weighted
image (Figure 2). It was evaluated with FNAC
which revealed benign mesenchymal spindle cell
neoplasm, suggestive of nerve sheath tumor with
possibility of schwannoma (Figure 3). The
patient underwent transoral total excision of
the mass under general anesthesia with
nasotracheal intubation. For the proper
visualization of the base of tongue, frenulum of
tongue was incised; tongue was released from
floor of mouth and pulled out. An incision was
given in right lateral margin over the swelling.
After splitting the mucosa, mass is exposed,
mobilized by blunt dissection, and excised
totally (Figures 4&endash;6). Haemostasis was
ensured, and wound closed in layers.
Histopathological report revealed features of
schwannoma (Figure 7). For confirmation of the
tissue of origin, immunocytochemistry was done
and found strongly positive for S100 protein.
There was no symptom or sign of recurrence in 12
months postoperative follow-up (Figure 8).
Discussion
Though this is not clear of the etiology of
the schwannoma, it is known to be derived from
nerve sheath Schwann cells, which surround
cranial, peripheral, and autonomic nerves
[6, 7]. The head and neck are rather
common location of this neoplasm. Intraoral
schwannoma mainly arise from the tongue,
followed by the palate, mouth floor, buccal
mucosa, gingiva, lip, and vestibule [8,
9], though the tongue is most commonly
involved [10]. The lesion is slow
growing, and thus, its onset is usually long
before presentation. Lingual schwannoma shows no
age or gender predisposition [11].
Usually, it presents as a painless lump in any
part of the tongue. The average size at
presentation was 2.4_cm. However, when the mass
exceeds 3.0_cm, dysphagia, pain (or discomfort),
dysphonia, and voice changes are usually present
(Table 1).
In the literature review of 61-year period
(from 1959 to 2019), 68 cases schwannoma of the
tongue were found, and 54% of them are male, and
the rest of them are female. More than half of
the cases were posterior tongue schwannomas
(56%). According to this review, the patients
had feeling of lump cases, respectively.
The mean age at diagnosis was nearly 25
years. Transoral excision was performed in 96%
cases. However, for two cases, carbon dioxide
laser was used for the tongue-base schwannoma,
and in three cases, submandibular approach was
used. There was no report of recurrence.
Clinically, the schwannomas may be
indistinguishable from other encapsulated benign
tumors, because biopsy and histological
examination are essential to formulate a correct
diagnosis. An excisional biopsy was performed to
formulate a correct diagnosis and finally find
out that the case was uncomplicated. Imaging has
become an integral part of evaluation for tongue
base lesions, and thus, a systematic imaging
approach should be considered. As demonstrated
in Fig. 9, lesions of the tongue can be divided
into infectious, neoplastic, and congenital
categories. An infectious process, such as an
abscess, appears hyperintense on T2WI with a
thick rimenhancing margin [12]. The
present case was totally asymptomatic before
surgery, and there was no major complication of
surgery. The option of complete resection was
chosen on the basis of the size of the lesion
and the age of the patient.
