Adnexal tumors

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Adnexal Tumors - A Hairy Situation

  • Tumors of skin appendages, classified by origin: hair follicle, sebaceous, apocrine, or eccrine glands.
  • Cylindroma: "Turban tumor" on head/scalp. Histology shows nests of basaloid cells fitting like a "jigsaw puzzle."
  • Syringoma: Benign eccrine duct tumors, often on eyelids. Ducts have a characteristic comma or "tadpole" shape.
  • Trichoepithelioma: Benign follicular tumor. Resembles Basal Cell Carcinoma (BCC) but lacks stromal retraction.

Brooke-Spiegler syndrome is an autosomal dominant condition caused by a germline mutation in the CYLD gene, leading to multiple cylindromas, trichoepitheliomas, and spiradenomas.

Follicular Tumors - Hair Apparent

  • Trichoepithelioma
    • Benign, often multiple papules on the face.
    • Histo: Basaloid islands, horn cysts, abortive hair papillae.
    • Associated with Brooke-Spiegler syndrome (CYLD gene).
  • Pilomatricoma (Pilomatrixoma)
    • Solitary, firm, deep nodule; common in children/young adults.
    • Histo: Basaloid cells, eosinophilic "ghost cells", and calcification.
  • Trichilemmoma
    • Smooth papule, often on the face.
    • Histo: Lobules of clear cells (glycogen-rich), peripheral palisading.
    • Marker for Cowden syndrome (PTEN mutation).

Pilomatricoma histology: Basaloid and ghost cells, necrosis

⭐ Pilomatricoma's key feature is "ghost cells" (anucleated shadow cells) on histology. It's often linked to activating mutations in the β-catenin gene (CTNNB1).

Sebaceous Tumors - Oily Origins

Histopathology of Sebaceous Adenoma

  • Sebaceous Adenoma:

    • Benign, slow-growing yellow papule; typically on the head/neck of older adults.
    • Histology: Lobules of mature sebocytes with bubbly, vacuolated cytoplasm mixed with basaloid cells.
  • Sebaceous Carcinoma:

    • Malignant, aggressive tumor, often on the eyelid (Meibomian glands).
    • May mimic chalazion or blepharitis, leading to delayed diagnosis.
    • Histology: Infiltrative growth, cellular atypia, necrosis, and pagetoid spread.

Muir-Torre Syndrome: The presence of any sebaceous neoplasm (especially adenoma) should raise suspicion for this autosomal dominant syndrome, a variant of HNPCC/Lynch syndrome, associated with visceral malignancies (most commonly colorectal cancer).

Sweat Gland Tumors - Hot & Bothered

  • Syringoma: Benign adenomas of intraepidermal eccrine ducts. Presents as multiple, small, skin-colored papules, typically around the eyes (periorbital). More common in women.
    • Histo: Tadpole-like ducts.
  • Eccrine Poroma: Benign tumor, often a solitary, pink/red papule or nodule on palms or soles of older adults.
  • Cylindroma: Benign, slow-growing tumor. Can present as a solitary lesion or multiple nodules on the scalp ("turban tumor"). Associated with Brooke-Spiegler syndrome (AD, CYLD gene mutation).

Cylindroma (Turban Tumor) Clinical Presentation

⭐ On histology, cylindromas are classic for islands of basaloid cells that fit together tightly, resembling a "jigsaw puzzle."

High‑Yield Points - ⚡ Biggest Takeaways

  • Cylindromas show a "jigsaw puzzle" pattern and are linked to Brooke-Spiegler syndrome, often presenting as a "turban tumor".
  • Syringomas are benign sweat duct tumors, commonly appearing as small papules around the lower eyelids.
  • Pilomatricomas are firm nodules with characteristic "ghost cells" on histology and are associated with myotonic dystrophy.
  • Sebaceous carcinoma, an aggressive malignancy of the eyelid, is strongly associated with Muir-Torre syndrome.
  • Trichoepitheliomas are benign follicular tumors; multiple lesions also suggest Brooke-Spiegler syndrome.

Practice Questions: Adnexal tumors

Test your understanding with these related questions

A 7-year-old girl comes in to the emergency department with her mother for swelling of her left periorbital region. Yesterday morning she woke up with a painful, warm, soft lump on her left eyelid. Eye movement does not worsen the pain. Physical examination shows redness and swelling of the upper left eyelid, involving the hair follicles. Upon palpation, the swelling drains purulent fluid. Which of the following is the most likely diagnosis?

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Flashcards: Adnexal tumors

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Lynch syndrome and some sporadic colorectal carcinomas arise via the _____ instability pathway

TAP TO REVEAL ANSWER

Lynch syndrome and some sporadic colorectal carcinomas arise via the _____ instability pathway

microsatellite

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