8/17/2019 1-s2.0-S038581461100023X-main

1/4

Lateral dermoid cyst of the floor of mouth: Unusualradiologic and pathologic findings

Harrison W. Lin a,d,*, Amanda L. Silver a,d, Mary E. Cunnane b,e,Peter M. Sadow c,f , David A. Kieff a,d

a Department of Otolaryngology-Head and Neck Surgery, Ma ssachusetts Eye and Ear Infirmary, Boston, MA, United Statesb

 Department of Radiology, Massachusetts Eye and Ear Infirmary, Boston, MA, United Statesc Department of Pathology, Massachusetts General Hospital, Boston, MA, United States

d Department of Otology and Laryngology, Harvard Medical School, Boston, MA, United States

e Department of Radiology, Harvard Medical School, Boston, MA, United Statesf  Department of Pathology, Harvard Medical School, Boston, MA, United States

Received 14 October 2010; accepted 17 January 2011

Available online 21 February 2011

Abstract

A lateral dermoid cyst is a rare lesion of the floor of mouth, with only 12 cases reported in the literature. We describe the case of a 60-year-

old man with a slowly enlarging mass in the submandibular region. Magnetic resonance imaging demonstrated a lesion containing multiple

uniformly rounded foci, creating a ‘‘sack-of-marbles’’ appearance. Needle aspirations showed atypical findings, and the mass was excised.

Histopathology revealed a cyst containing a keratinizing stratified squamous epithelial lining with apocrine and eccrine glands. These findings

were diagnostic of a dermoid cyst, which should be considered in the differential diagnosis of any midline or lateral cervical lesion.

# 2011 Elsevier Ireland Ltd. All rights reserved.

Keywords:  Dermoid; Neck mass; Neoplasm; Head and neck imaging; Head and neck pathology

1. Introduction

Dermoid cysts are uncommon, benign congenital tumors

of ectodermal origin that can occur in any region of the body.

Believed to arise during fetal development when ectodermal

differentiation and entrapment occur along lines of 

embryonic fusion, these lesions can be divided into three

distinct histopathologic subtypes, including epidermoid,

dermoid and teratoid varieties. While the ovaries and sacral

region are the most common location for these masses,nearly 7% occur in the head and neck region, and more

specifically, dermoid cysts of the floor of mouth account for

1.6% of all cases [1]. Furthermore, of the dermoid lesions

occurring the floor or mouth, only about 6% are found

laterally and present in the submandibular space, with a total

of only 12 such cases reported in the literature to date [2,3].

We present an additional case and provide uniquely detailed

radiologic, surgical and histopathologic findings. This case

is highly unusual in three respects: (1) that the lesion became

clinically significant in the seventh decade of the patient’s

life; (2) that the lesion was located in the tongue base and

submandibular regions where it exerted considerable mass

effect; and (3) that the radiographic and gross histopatho-

logic findings were exceptionally xenotypic in appearance.

2. Case report

A 60-year-old gentleman presented to our institution with

a two-year history of a painless and slowly enlarging mass of 

the right anterior neck. On physical examination, a

moderate-sized mass protruding from the right submandib-

ular region and mild fullness of the right floor of mouth were

www.elsevier.com/locate/anlAuris Nasus Larynx 38 (2011) 650–653

* Corresponding author at: Massachusetts Eye and Ear Infirmary, 243

Charles Street, Boston, MA 02114, United States. Tel.: +1 617 573 3654;

fax: +1 617 573 3939.

E-mail address:  harrison_lin@meei.harvard.edu (H.W. Lin).

0385-8146/$ – see front matter # 2011 Elsevier Ireland Ltd. All rights reserved.

doi:10.1016/j.anl.2011.01.002

http://dx.doi.org/10.1016/j.anl.2011.01.002mailto:harrison_lin@meei.harvard.eduhttp://dx.doi.org/10.1016/j.anl.2011.01.002http://dx.doi.org/10.1016/j.anl.2011.01.002mailto:harrison_lin@meei.harvard.eduhttp://dx.doi.org/10.1016/j.anl.2011.01.002

8/17/2019 1-s2.0-S038581461100023X-main

2/4

noted. With bimanual intraoral palpation, a large, round, firm

and non-tender mass could be appreciated. Fiberoptic

nasolaryngoscopy, moreover, revealed base of tongue protru-

sion posteriorly, resulting in moderate vallecular effacement.

Multiple fine needle aspirations (FNA) provided variable

findings, including a biopsy that revealed atypical

cells concerning for squamous cell carcinoma. Acomputed tomography (CT) scan demonstrated a

4.4 cm 3.0 cm 3.5 cm lesion with mixed attenuation

and scattered heterogeneous calcifications (Fig. 1). Magnetic

resonance imaging (MRI) further revealed a strikingly

xenotypic mass containing multiple uniformly-rounded foci

measuring up to 3 mm in diameter, creating a ‘‘sack of 

marbles’’ appearance on cross-sectional imaging (Fig. 2).

The patient was consented for a transcervical excision of 

the lesion and possible tracheotomy or postoperative

intubation given the large size and the lateral submandibular

presentation of the mass, as well as concern for post-

operative local edema triggering airway compression at the

level of the tongue base. Intraoperatively and following

submandibular gland removal, the mass was noted to be

deep to the mylohyoid muscle and surrounded by extensive

fibrosis that encased the right lingual nerve. The main trunk 

of the nerve was preserved. The hypoglossal nerve was also

adherent to the capsule of the mass, but was carefully

dissected free from it and preserved. Following   en bloc

removal of the mass, incision through the capsule of the

lesion demonstrated a large cyst containing numerous

regularly shaped yellow, 3 mm spheroid fragments of equal

size that had a paste-like consistency (Fig. 3). Histopathol-

ogy revealed that the cyst contained an attenuated and

keratinizing stratified squamous epithelial lining with rareunderlying skin appendages, including apocrine and eccrine

glands, within the cyst wall (Fig. 4). These findings were

diagnostic of a dermoid cyst.

Due to the extensive dissection required to access the

posterio-superior aspect of the cyst and concern for resulting

oropharyngeal/tongue base edema, the patient remained

intubated overnight while on parenteral corticosteroid

therapy and was successfully extubated on the first

postoperative day. At last follow-up the patient is doing

well and without signs of recurrence. He initially had a

praxia of the mild lingual and hypoglossal nerve praxia

ipsilaterally that has subsequently resolved by six weeks

post-operatively.

3. Discussion

Dermoid cysts of the floor of mouth are uncommon

tumors found in the midline in the vast majority of cases

[2,4] and typically present in the second or third decades of 

life as a painless, slow-growing mass in the floor of mouth,

submentum or anterior neck   [5]. True lateral cervical

presentations are exceedingly rare, with only 12 cases of 

purely lateral cervical dermoid cysts reported in the

literature. Of note, Teszler and colleagues developed an

anatomico-surgical classification system of dermoid cysts of 

the floor of mouth to assist surgeons with the decision-

making process of the surgical approach. In their algorithm,

a dermoid cyst can be grouped into one of seven classes

based on its median versus lateral location and relationships

to the mylohyoid and geniohyoid muscles [3]. Here we have

described a highly unusual case of a supramylohyoid

dermoid cyst presenting the seventh decade of life as a

lateral cervical mass.

Histopathologically, the terms ‘‘dermoid’’ or ‘‘dermoid

cysts’’ have been used as umbrella titles to describe the three

subtypes of these congenital cysts containing keratinous

squamous material. Epidermoid cysts or epidermal inclusion

cysts are lesions lined with a simple squamous epitheliumwith no adnexal structures. True dermoids are stratified

squamous epithelial-lined cysts that contain skin adnexal

structures, including hair, hair follicles, sebaceous and sweat

glands. Finally, teratoid cysts are masses lined with a variety

of epithelia, including stratified squamous and ciliated

respiratory epithelia, and contain elements of ectodermal,

endodermal and/or mesodermal origin [4]. The differential

 H.W. Lin et al. / Auris Nasus Larynx 38 (2011) 650–653   651

Fig. 1. Contrast-enhanced CT imaging in axial, (A) coronal, (B) sagittal, (C) soft tissue windows demonstrated a 4.4 cm 3.0 cm 3.5 cm mass containing

heterogeneous calcifications and rounded fat attenuation.

8/17/2019 1-s2.0-S038581461100023X-main

3/4

diagnosis of a lateral submandibular mass should include

these cystic masses, along with other embryological

anomalies, neoplasms, odontogenic or mucus extravasation

masses, infectious and inflammatory processes as well as

salivary gland pathology [3,6].

CT imaging of dermoid cysts has been reported to show

the characteristic xenotypic ‘‘sack of marbles’’ configura-

tion, [7]  and more recently, similar findings have also been

demonstrated with MRI. The smaller foci within the cyst are

believed to result from a coalescence of lipid and keratinous

material and together create the unique radiologic appear-

ance considered pathognomonic for dermoid cysts   [7].

Although CT imaging proved less helpful in this case, the

‘‘sack of marbles’’ finding seen on MRI strongly suggested a

dermoid cyst diagnosis. This in turn aided surgical planning,

which was previously complicated by FNA resultssuggestive of malignancy.

While FNA biopsy of dermoid cysts may provide

sufficient diagnostic material, this method is complicated

by potential sampling bias, given the copious keratinaceous

cyst contents and relatively scarce epithelium-lined cyst

wall. Accordingly, needle biopsies of a dermoid cyst will

often yield inconclusive, variable or non-diagnostic results.

Although FNA cytology was concerning for malignancy in

this case, both the clinical course and MRI appearance of the

cyst were highly suggestive of a benign process and

consequently a decision was made to proceed with surgical

excision without further surgical or radiologic evaluation for

regional or distant metastatic disease.

Thelocation of a dermoid cyst relative to the genioglossus,

geniohyoid, mylohyoid, digastric and platysma muscles has

been suggested to determine the most appropriate means of 

surgical excision of the mass, including intraoral, submental

and submandibular approaches [3,6]. MRI has been reported

to be superior to other imaging modalities in demonstrating

the exact location and extent of cystic lesions of the floor of 

mouth   [8]. Although the MRI findings in isolation could

imply that an intraoral approach would have been the

preferred means of accessing and excising the lesion in this

case, the lateral cervical presentation of the mass in thesubmandibular region and the immense size of the cyst

favored a transcervical approach, as has been suggested by

others [3,5,6]. Surgical excisionis the onlyeffective treatment

for dermoid cysts. Recurrence is uncommon and typically is

related to cyst remnants left on the genial tubercle or hyoid

bone [5]. Similarly, malignant degeneration of dermoid cysts

of the floor of mouth is exceedingly rare and has only been

reported in patients with lesions of the teratoid  subtype [5,7].

 H.W. Lin et al. / Auris Nasus Larynx 38 (2011) 650–653652

Fig. 2. Magnetic resonance imaging revealed a cystic lesion containing multiple uniformly-rounded foci measuring up to 3 mm that were dark on T2 (A, axial)

and STIR (B, coronal) images, and bright on T1 (C, sagittal) images.

Fig. 3. (A) The mass was excised en bloc via a transcervical approach. (B) Incision through the cyst wall revealed numerous yellow, spheroid fragments with a

paste-like consistency.

8/17/2019 1-s2.0-S038581461100023X-main

4/4

4. Conclusions

Laterally situated dermoid cysts of the floor of mouth are

rare lesions but should nevertheless be considered in the

differential diagnosis of any lateral oral cavity or cervical

lesion in both adult and pediatric patients. FNA interpreta-

tion is limited due to the cystic nature of these masses.

Radiologic imaging, in particular MRI, may provide nearly

pathognomonic xenotypic findings that are valuably

diagnostic and may influence surgical planning. Surgical

excision is curative, and recurrences are rare.

References

[1] New GB, Erich JB. Dermoid cysts of the head and neck. Surg Gynecol

Obstet 1937;65(48).

[2] King RC, Smith BR, Burk JL. Dermoid cyst in the floor of the mouth.

Review of the literature and case reports. Oral Surg Oral Med Oral

Pathol 1994;78:567–76.

[3] Teszler CB, El-Naaj IA, Emodi O, Luntz M, Peled M. Dermoid cysts of 

the lateral floor of the mouth: a comprehensive anatomo-surgical

classification of cysts of the oral floor. J Oral Maxillofac Surg

2007;65:327–32.

[4] Meyer I. Dermoid cysts (dermoids) of the floor of the mouth. Oral Surg

Oral Med Oral Pathol 1955;8:1149–64.

[5] Longo F, Maremonti P, Mangone GM, De Maria G, Califano L. Midline

(dermoid) cysts of the floor of the mouth: report of 16 cases and review

of surgical techniques. Plast Reconstr Surg 2003;112:1560–5.

[6] Fuchshuber S, Grevers G, Issing WJ. Dermoid cyst of the floor of 

the mouth—a case report. Eur Arch Otorhinolaryngol 2002;259:

60–2.

[7] Koeller KK, AlamoL, Adair CF, Smirniotopoulos JG. Congenital cystic

masses of the neck: radiologic–pathologic correlation. Radiographics1999;19:121–46.

[8] Vogl TJ, Steger W, Ihrler S, Ferrera P, Grevers G. Cystic masses in the

floor of the mouth: value of MR imaging in planning surgery. AJR Am J

Roentgenol 1993;161:183–6.

 H.W. Lin et al. / Auris Nasus Larynx 38 (2011) 650–653   653

Fig. 4. (A) Cyst wall. Note the keratinizing, stratified, squamous epithelial surface (H&E; 200). (B) Chronic inflammation (arrow heads), keratinizing

squamous surface (double arrow) and attenuated squamous surface (single arrow) are seen in the cyst wall (H&E; 40). (C) Apocrine glands (arrow head),

eccrine glands (double arrow) and attenuated squamous surface (single arrow) are also noted (H&E; 40). (D) Salivary glands adjacent to cyst wall and

pericystic connective tissue with chronic inflammation (H&E; 100).