Skin and relative connective tissue

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Skin and relative connective tissue
SYLLABUS RBP(Robbins Basic Pathology)
Chapter The Skin
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Skin and relative connective tissue

• Dermatofibroma
• Pilomatrixoma
• Basal cell carcinoma
• Melanocytic nevus
• 323 Seborrheic keratosis

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Dermatofibroma

• fibroblast-like spindle cells
• histiocytes
• small blood vessels
• overlying epidermis with elongated rete ridges
  and with increased basal melanin (dirty fingers)

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Dermatofibroma
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Dermatofibroma
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Pilomatrixoma

• uniform small basaloid cells at periphery
• large squamous cells with gradual loss of nuclei
  (shadow cells) (older lesions show less basaloid
  cells and more shadow cells)
• often associated granulomatous inflammation and
  calcification

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Pilomatrixoma
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Pilomatrixoma
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Basal cell carcinoma

• neoplastic cells similar to basal layer of
  epidermis, basophilic with high
  nuclear/cytoplasmic ratio
• nests typically have marked peripheral
  palisading
• prominent fibroblastic stroma arranged around
  tumor lobules

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Basal cell carcinoma
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Basal cell carcinoma
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Melanocytic nevus

• nests of cohesive melanocytes, which are
  generally cuboidal and occasionally spindled,
  with inconspicuous nucleolus, variable melanin
• individual melanocytes do not extend beyond
  nests at lateral margins
• nests of similar size with rounded, sharp
  borders
• little to no inflammation

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Melanocytic nevus
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Melanocytic nevus
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Seborrheic keratosis

• acanthosis, hyperkeratosis, and papillomatosis
• well-circumscribed proliferation of basaloid
  cells completely replacing normal epidermis with
  horn pseudocysts
• no dermal invasion
• no mitoses, necrosis, ductal structures, or
  peripheral palisading
• basal melanin common

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Seborrheic keratosis
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Seborrheic keratosis