oral choristomas

2. PRESENTED BY: DR. XAVIER PRADEEP D’MELLO A
GUIDED BY: DR. DINKAR DESAI
PROFAND HEAD

3. INTRODUCTION
DEFINITION
CLASSIFICATION.
PATHOGENESIS.
CLINICAL
PRESENTATION.
DIAGNOSTIC
METHODS.
DIFFERENTIAL
DIAGNOSIS.
TREATMENT .
CONCLUSION.
REFERENCES.

4. INTRODUCTION

5.  Tumor like mass of normal cells in abnormal location.
 Term applies to a cohesive tumor like mass consisting of normal cells in an abnormal
location.
 Distinguished from hamartoma which is a tumor like malformation composed of a focal
overgrowth of mature normal cells located where they are normally found.
 Teratoma composed with tissue or organ components resembling normal derivatives of
more than one germ layer.

6. DEFINITION

7. “Tumor like growth developed from groups of primordial cells (organ rudiments),
which are separated from their original tissue or organ”.
Albrecht in 1904
Batra R. The pathogenesis of oral choristomas. Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology 24 (2012) 110–114

8. “Masses arising from displaced heterotopic tissues that are histologically normal
but are foreign to the site in which they are found”.
Smart and Lendon
Batra R. The pathogenesis of oral choristomas. Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology 24 (2012) 110–114

9. CLASSIFICATION

10. Salivary gland
choristoma
a. Central
b. Gingival
Cartilaginous
choristoma
Osseous choristoma
Lingual thyroid
choristoma
Lingual sebaceous
choristoma
Glial choristoma
Gastric mucosal
choristoma
a. Cystic
b. Solid

11. SALIVARY GLAND CHORISTOMAS

12. Describes
non-
neoplastic
aberrant or
ectopic
salivary gland
tissue
appearing
either as a
raised tumor
like mass or
as a tumor
like
radioluscency.
These ectopic
or aberrant
tissues should
not have any
connection
with normal
minor or
major salivary
glands.
Birth, 9–56
yrs.
Soft tissue
swelling in
gingival
gingival
salivary gland
choristomas.
Bone 
central
salivary gland
choristomas.
Gingival by
Moskow and
Baden in
1964.
Central by
Richard and
Ziskind in
1958.

13. PATHOGENESIS

14. CENTRAL
 The exact cause unknown.
Bhaskar offered a
possible origin of
intrabony salivary
gland tissue 
inclusion of retromolar
mucous glands.
Due to close proximity
of sites of
development of
retromolar mucous
glands, from oral
epithelium, to
retromolar area of
mandible, it is possible
for some of glandular
tissue to become
included in superior
aspect of mandible.
Such glandular tissue
would be located
above mandibular
canal.

15. Abbas and Bras agree.
 This theory fails to explain origin of lesion of anterior mandible.

16. Another theory
mucous metaplasia of
lining epithelium of an
odontogenic cyst.
Although it is
conceivable that
epithelial lining of
odontogenic cysts may
exhibit isolated areas
of mucous metaplasia,
it is unlikely that this
epithelium can
differentiate into
normal salivary gland
tissue.
Keeping in view
innocent nature and
relatively small size of
intraosseous gland.
Chou et al. presume that lesion may differentiate and develop from ectodermal cells
within mandible.

17. Exact cause unknown.
Ide et al., explained only
on basis of
developmental
displacement of minor
salivary glands.
G & D some of salivary
gland tissue located in
oral mucosa becomes
“trapped” & maintains its
relative position, within
gingiva producing an
outgrowth.
GINGIVAL

18. Brannon et al. also agree.
Another theory glandular
tissue demonstrates
pluripotentially of gingival
epithelium.
Appearance of aberrant
position of tissue may
reflect an ectopic location
of original
“ectomesenchymal
condensation” whose
presence induces
subsequent formation of
primordial epithelial bud of
salivary gland.

19. CARTILAGINOUS CHORISTOMAS

20. Zahn in
1885, first
described
oral soft
tissues.
Later, in 1892,
Berry reported
a case of
fibrochondroma
of tongue.
Cartilage,
metaplastic
cartilage, dystrophic
chondrometaplasia,
osteocartilage,
fibrochondroma,
chondroma,
enchondroma and
calcifying
chondroma.
In 1971 when
Knoll and
coworkers
favored term
‘choristoma’
because these
represented
heterotopic
tumor like
growths of
histologically
normal tissue.

21.  Reported in 1-day old infants to 90-year old female, mean age being 47 years.
 The most common site is tongue # gingival, buccal mucosa & soft palate.
 Distinguished from cartilaginous metaplasia, occurs in soft tissues beneath ill-fitting
dentures.
Characterized histologically by diffuse deposits of calcium & scattered cartilaginous
cells arranged in various stages of maturation in single or clustered foci.

22. PATHOGENESIS

23.  Exact cause unknown.
 Embryonal theory: Cartilage is developed from heterotropic fetal cartilaginous remnants.
 Moore et al. believe in embryonic development of cartilaginous choristomas of tongue.

24.  Similarly remnants, of Meckel’s cartilage another possibility of embryonic origin.
 Gentscheff found microscopic islands of hyaline cartilage in tongue of new borns &
adults, thus supporting theory of embryonic origin.

25.  Metaplastic theory: Development from pluripotent mesenchymal cells is resumed either
de novo or stimulated by some type of trauma, irritation or chronic inflammation.
 According to Unal and Erturk, origin might be from cartilaginous embryonic remnants
and this is a developmental phenomenon, although it is possible that this type of lesions
may originate from pluripotent mesenchymal cells, which occur more commonly in the
older age group.

26. Chou et al. undifferentiated mesenchymal cells as speculative.
 Result of cartilage formation from multipotential mesenchymal cells with proper
stimulation & by its active interstitial & appositional growth.
 Milles suggested that cartilaginous choristoma may arise from vestigial rests of cartilage.

27. OSSEOUS CHORISTOMAS

28. Tumor
like growth
normal, mature
lamellated bone
occurring in
soft tissues.
“osteoma mucosae” or “soft tissue
osteoma”,“osteoma cutis”.
Monserrat 1913.
“osseous choristoma” Krolls et al. 1917.

29. PATHOGENESIS

30.  Cause obscure.
 Monserrat believed that these lesions represent ossification of branchial arch remnants.
 He based his theory on the presence of these lesions in the area of foramen caecum, as
this is the site for development of structures of the first and third branchial arches and also
the area from where the second branchial arch normally disappears.
 Hirsch thought that they represented epignathous formation.
 Epignathous is a benign congenital teratoma of the oral cavity and the palato pharyngeal
region.

31.  Zuckerman favored congenital abnormality.
 Others included ossified lymphatic tissue, degenerating fibroma undergoing ossification
and metaplastic formation based on the transformation of mesenchymal cells under
traumatic or chronic inflammatory stimulation.
 Another theory proposed a focus of heterotopic bone formation within the soft tissues of
the tongue.
 Catalodo et al. and Jahnke and Daly proposed a developmental theory associated with the
remnants of thyroid gland tissue.

32. All these theories have been divided into two main categories:
1. The developmental theory.
2. The post traumatic theory.
 It is generally believed that post traumatic theory stands true for osseous choristomas of
buccal mucosa & anterior tongue.
 Developmental theories associated with remnants of branchial arch or thyroid gland
would account for occurrence of such lesions in posterior third of dorsum of tongue, in
vicinity of foramen caecum & circumvallate papillae.

33. LINGUAL THYROID CHORISTOMAS

34.  Ectopic thyroid tissue has been found from tongue to diaphragm. Lingual thyroid is
termed choristoma in some cases because its tumor like manifestation arising from ectopic
thyroid tissue differentiates this clinical entity from simple latent thyroid tissue.
 Latent ectopic thyroid tissue is a developmental anomaly consisting of an aggregate or
small scattered islands of thyroid tissue occurring in base of tongue or any other point
along route of descent of thyroid primordium.

35. Approximately, one of every 10 people but lingual thyroid choristoma is rare.
 First reported case is by Hickman in a new born child who died of suffocation from a
lingual thyroid 16 h after birth.
 Incidence is 1:100,000  dysphagia, dysphonia, dyspnoea, pain, hemorrhage or “fullness
in throat”.

36. 1. Lesion should be a tumor like mass occurring in mid portion of tongue b/w foramen
cecum & epiglottis.
2. Diagnosis is confirmed by radioactive iodine methods or by histological examination.

37. PATHOGENESIS

38. Embryonic development of thyroid gland is from endodermal invagination of ventral
floor of pharynx.
Tongue also forming in pharyngeal floor, is anatomically associated with thyroid gland.
Attached to it by means of thyroid tract.
Extends from foramen cecum at base of tongue to thyroid isthmus.

39. After birth, foramen cecum represents vestigial remnant of this tract.
Possible for thyroid tissue to be located anywhere along this tract.
Here probably tissue arises from a thyroid anlage which failed to migrate to its
predetermined position.

40. SEBACEOUS GLANDCHORISTOMAS

41. Term first
used by
Leider et al.
Sebaceous glands
have been reported
to occur in various
sites in the oral
cavity {Fordyce’s
granules}.
Mass of
sebaceous
glands in an
unusual
location,
dorsum of
tongue.

42. PATHOGENESIS

43. According to
Guiducci and
Hyman, due to
ectodermal
sequestration
within tongue
during
embryogenesis.
According to
Leider et al. and
Knapp sebaceous
glands associated
with thyroglossal
duct like structures
originated from
remnants of
thyroglossal tract.
But Guiducci and
Hyman did not
agree with this
theory as there
was no lymphoid
tissue in the
vicinity of their
lesion such as is
usually found
associated with
vestigial
thyroglossal ducts.
Other possible
origin in tongue
is from ductus
lingualis.

44. GLIAL CHORISTOMAS

45. Occurrence of
extracranial brain
tissue very rare.
Most observed nasal
region.
For these masses to
occur in oral cavity
with no connection
with CNS is
extremely rare.
Reid in 1852,
described by Schmidt.
“Heterotopic brain
tissue” “Extracranial
gliopma”.
Cannot be called
heterotopic brain
tissue because this
term does not reflect
fact that ectopic
tissue grows like a
tumor like mass

46.  Term glioma inappropriate, represents true neoplasm.
 Term “teratoma” when no mesodermal or endodermal components identified.
 Chou et al., proposed term “glial choristoma” which represents both normal ectopic tissue
& its tumor like growth.
 Thus, considered as brain heterotopias composed of ectopic CN tissue arising as
developmental malformation with a tumor like growth.
1. Paraneuroaxial glial choristomas.
2. Glial choristomas remote from neuroaxis.

47. PATHOGENESIS

48.  Generally considered congenital malformations.
 No single theory fulfills all criteria.
 Origin of PNAGC attributed to herniation of fetal cerebral tissue occurs during embryonic
development, as in development of encephaloceles, but with subsequent separation from
cranial cavity.
 Such herniations occur through cleft in bone or through a foramen of skull.

49.  Proposed by Karma et al. & later Whitaker et al. agreed.
 Does not explain presence of glial choristomas in ventral foregut structures such as
tongue, far from known embryonic canals.
 Absence of neural cells & failure to find site of herniation, has lead authors to consider
origin of glial choristomas from neural crest cells in head and neck which have ability to
undergo neuroglial development.

50.  Macomber & Wang proposed that glial choristomas are caused by separation of cells
from anterior part of brain in early embryonal development.
 Occur before closure of palate.
 Explains involvement of tongue to some extent.
 Displaced neural tissue present early in occipital somites from which tongue muscles
originate.

51.  It seems that nests of pluripotential cells become separated prior to complete fusion of
neural tube & are brought to extra cranial tissues in association with normally migrating
cells.
 Shapiro, Mix & Kurzer et al.  lesion develops from misplaced primordium.
 Other investigators recommended that glial choristomas arise from preferential
development of one germinal layer of a teratoma in a neural cellular line.

52. GASTRIC/RESPIRATORY MUCOSAL CHORISTOMAS

53. Heterotopic gastric
elements present in
oral cavity.
First
description
given by
Toymar as
stomach
mucosa at
base of
tongue.
Present as a
cyst within
oral cavity but
also as solid
entities.

54. 1. Gastric cystic choristoma: Defined as a cystic lesion in oral cavity, that is usually lined
partially by stratified squamous epithelium & partially by gastric mucosa, & occasionally
by intestinal epithelium.
2. Solid gastric mucosal choristoma: Solid mass in oral cavity that usually contains gastric
mucosal elements & some times, intestinal components also.

55. PATHOGENESIS

56.  Postulated to arise from misplaced embryonic gastric rests, because in 3–4mm embryo (4
weeks) undifferentiated primitive stomach lies in mid neck region close to primordium of
tongue.
 Assumed that endodermal gastric mucosa becomes entrapped in midline of tongue by
fusion of lateral lingual swelling over tuberculum impar.
 Also gastric epithelium occur in oesophagus of 7.8% of infants, & in 51% located in
upper third.

57.  Woolgar & Smith reported that mucin in heterotopic gastrointestinal cyst wall is
different in composition from that in histologically similar normal gastrointestinal
mucosa, suggesting that this lesion originates from undifferentiated endoderm subjected
to inductive influences, which result in varying amounts of differentiation.

58.  This concept however, would not account for undifferentiated endoderm of ventrally
migrated gastric anlage or entrapped endoderm of floor of primitive stomodeum.
 Lingual cystic choristomas lined by respiratory epithelium have also been reported and
have been labeled as anterior median lingual cyst, median lingual cyst, lingual
bronchogenic cyst or lingual cyst of foregut origin.
 Both respiratory & enteral epithelium have been found to line same cyst.

59.  Pathogenesis for these choristomatous cysts has been attributed to embryogenic theory of
respiratory and gastrointestinal lingual cysts, which maintains that both are derived from
primitive foregut.
 During 3rd & 4th weeks of gestation, human embryonic folding results in formation of
endodermal gut tube.
 Cranial portion of gut tube is foregut, which gives rise to proximal digestive tract
(pharynx to proximal duodenum) & tracheobronchial tree (via a keel-shaped outpouching
called the respiratory diverticulum).

60. EPIDERMAL & FOLICULLAR CHORISTOMAS

61. Unusual finding characterized by abrupt replacement of normal oral mucosal epithelium
with epidermis-like epithelium exhibiting hyperorthokeratosis, hypergranulosis, melanin
pigmentation, and underlying adnexal structures, such as sebaceous glands, hair follicles,
and/or sweat glands.
Epidermal choristoma 1st reported by Azorin et al. 2005 1-month-old boy with three
pigmented macula on tongue.
Oral follicular choristoma, 1st reported by Arwill et al 9-year-old girl with a nodular lesion
on lingual alveolar mucosa adjacent to mandibular central incisors.

62. Microscopic examination showed presence of hair follicles, sebaceous glands, a keratin-
containing cyst, and pigmented cells within connective tissue.
These investigators thought that these features were suggestive of a folliculoma as
described by Kligman and Pinkus, and thus they proposed the term “follicular
choristoma.”
Sood described a second case 46-year-old anterior floor of mouth.

63. PATHOGENESIS

64.  Mechanism not well understood.
Skin graft procedures, traumatic skin implantation, or migration of skin structures due to
adjacent pathologic processes.
 Sood theorized that mechanisms for follicular choristoma development might include
formation of dermal appendages by ectodermal epithelial remnants or spontaneous
marsupialization of an undetected submucosal dermoid cyst.
 Although an epidermal choristoma is extremely rare, D/d of melanin containing lesions
within oral cavity.

68. DIAGNOSITC METHODS

69.  HISTORY.
 CLINICAL EXAMINATION.
 HISTOPATHOLOGY.
 RADIOGRAPHS.
 ENDOSCOPY.

70. TREATMENT

71. CASE REPORTS

80. to conclude…

81. REFERENCES

82. R. Batra. The pathogenesis of oral choristomas. Journal of Oral and Maxillofacial Surgery, Medicine,
and Pathology 24 (2012) 110–114.
Chou et.al.. Choristomas of the oral cavity: A review oral surc oral med oral pathol. November 1991(72)
5.
Mainak Dutta. Naso-oropharyngeal choristoma (hairy polyps): an overview and current update on
presentation, management, origin and related controversies. Eur Arch Otorhinolaryngol. 2004.
Edoardo Gorini. Osseous Choristoma of the Tongue: A Review of Etiopathogenesis. Case Reports in
Otolaryngology Volume 2014.

83. Izumi Yoshioka. Epidermal choristoma arising on the midline gingiva as a congenital epulis: A case
Report. Journal of Cranio-Maxillo-Facial Surgery 40 (2012) 812e814.
Arwill T, Heyden G, Ramstadt A: Follicular choristoma of the gingiva: A peculiar lesion. Oral Surg Oral
Med Oral Pathol 35(1): 89e92, 1973.
Raymond L. Chai. Congenital Choristomas of the Oral Cavity in Children. Laryngoscope, 121:2100–
2106, 2011.
Mandell DL, Ranganathan S, Bluestone CD. Neonatal lingual choristoma with respiratory and gastric
epithelium. Arch Otolaryngol Head Neck Surg 2002;128:1321–1324.

84. Angela C. Chi. Epidermal Choristoma of the Oral Cavity: Report of 2 Cases of an Extremely Rare
Entity. J Oral Maxillofac Surg 2010.
S. O. Krolls, J. R. Jacoway, and W. N. Alexander, “Osseous choristomas (osteomas) of intraoral soft
tissues,” Oral Surgery, Oral Medicine, Oral Pathology, vol. 32, no. 4, pp. 588–595, 1971.
M. Nash, T. Harrison, P.-T. Lin, and F. E. Lucente, “Osteoma of the tongue,” Ear, Nose and Throat
Journal, vol. 68, no. 1, pp. 63–65, 1989.
S. Weitzner, “Osseous choristoma of the tongue,” Southern Medical Journal, vol. 79, no. 1, pp. 69–70,
1986.

85. Arwill T, Heyden G, Ramstedt A: Follicular choristoma of the gingiva: A peculiar lesion. Oral Surg
Oral Med Oral Pathol 35:88, 1973.
Unal T, Erturk S (1994) Cartilaginous choristoma of the gingiva. Report of two cases; review of the
literature of both gingival choristomas and intraoral chondromas. Ann Dent 53:19–27.
Kainz J, Kobierski S, Jakse R et al (1990) Choristoma of the soft palate. Eur Arch Otorhinolaryngol
247(4):264–266.
Horta et.al, Oral glial choristoma. Oral Oncology EXTRA (2005) 41, 53–55.