Benign Tumours of Epithelial Origin

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Benign Tumours of Epithelial Origin

• Papilloma
• C/f
• Age 2-5th decade of life
• More in males, can affect an sex
• Most common site is tongue, followed by buccal
  mucosa, lip, gingiva
• Clinically- cauliflower like growth, having
  finger like projections, usually pedunculated,
  may be sessile, pinkish in colour if
  keratinized, then colour is greyish white
• Usually painless unless secondarily infected
• Resembles verucca vulgaris occuring on fingers,
  caused by HPV

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• Papilloma Contd..
• Histological Features
• Each finger like process has a connective tissue
  core covered by epithelium which is hyperplastic
• If keratinized, then para or ortho keratinization
  is found on the surface of projections
• Inflammatory cells may be present if ulcerated
  surface

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Keratoacanthoma or self healing carcimoma

• It is a benign epithelial neoplasm which
  histologically resembles carcinoma
• Etiology unknown, suggested to be viral, genetic,
  chemical carcinogens etc.

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Keratoacanthoma

• CLINICAL FEATURES
• Usually occurs on external surface like lip,
  nose, cheek, Zygoma etc.
• Age 5th to 7th decade of life
• More common in males
• 1.5 to 2 cm in diameter

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Keratoacanthoma Clinical course

• Initially appears as nodule, which ulcerates and
  becomes crater like ulcerated nodule, keratin is
  present within the ulcer
• It grows to its full size in 4-8 weeks, remains
  static, then in following 6-8 weeks, it expels
  the central keratin core and heals, hence called
  as self healing carcinoma, recurrence is rare.

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Keratoacanthoma

• Histological Features
• Hyperplastic squamous epithelium growing into
  underlying connective tissue
• Surface covered by thick layer of ortho para
  Keratin with central plugging
• Occasional dysplastic features are seen in the
  epithelial cells
• At the leading margin of tumour, islands of
  epithelium appear to be invading connective
  tissue and it is almost impossible to
  differentiate it from Squamous cell Carcinoma
• Perineural invasion has also been reported, but
  does not have an adverse effect on biological
  nature of tumour

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Keratoacanthoma H/F Contd..

• Connective tissue is infiltrated with chronic
  inflammatory cells
• At the margin of the lesion, the normal adjacent
  epithelium is elevated towards the central
  portion of crater, then an abrupt change of
  normal epithelium occurs into Hyperplastic
  Acanthotic epithelium
• Hence, Inclusion of the adjacent border of
  specimen is must in the biopsy to reach a
  conclusion.

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Benign Epithelial Tumors Contd..

• Pigmented Cellular Nevus
• Nevus is a developmental tumor like malformation,
  composed of nevus cells.
• Melanin pigment is present in tumor cells

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Pigmented Cellular Nevus

• Two types
• Congenital
• Small - 3-5 cms in size
• Garment - more than 10 cms in size
• Acquired
• Intradermal
• Junctional
• Compound
• Spindle cell type
• Blue Nevus

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Pigmented Cellular Nevus

• Congenital Nevus
• These are macules, Pale or coloured and are
  raised or elevated
• These subsequently show hair growth on their
  surface
• Are present at birth

• Acquired Nevus
• Present 2-3 yrs after birth
• Number increases till 3rd decade of life, then
  decrease in number
• Usually small in size
• Pigmented
• With or without hair growth on surface
• This type is mostly seen in oral cavity, common
  sites are palate gingiva

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• Histopathology
• Main cell is nevus cell. These are large ovoid
  cells with vesiculated nuclei, and pale cytoplasm
• They are derived from neural crest cells

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Melanocytes in Normal epithelium
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Normal benign lesions (melanocyte related)
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Junctional nevus
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• Compound Nevus
• Shows junctional activity
• nests of nevus cells in connective tissue.

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Intradermal Nevus
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Blue Nevus