PILOMATRICOMA
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Synonyms-calcifying epithelioma of Malherbe, pilomatrixoma and trichomatricoma
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The tumor shows features of matrical follicular differentiation.
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Age – Occurs bimodaly in age group below 25 years and above 50 years
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Site – Most common is head and neck but can also arise in any part.
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Common presentation
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Slow growing cystic nodule
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Multiple tumors occur in familial cases having myotonic dystrophy (steinert’s syndrome)
Morphology
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Tumor is initially a cystic dermal proliferation which is lined by both germinative matrical cells and infundibular type of cells.
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Germinative matrical cells have basaloid appearance and exhibit monotonous round nuclei with small nucleoi and amphophilic cytoplasm. Brisk mitotic activity can be seen.
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These basaloid cells phase into an intermediate zone in which cytoplasm is eosinophilic and nuclei appears to washed away(ghost cells)
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Dsytrophic calcification can occur in this zone and later metaplastic ossification can also occur.
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Giant cell reaction occurs in the adjacent region due to extravasated keratin.
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In ancient pilomatricoma secondary heterotpoic ossification can occur and intratumoral medullary hematopoiesis may also be seen.
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Few tumors may show budding groups of tumor cells which infiltrate into the surrounding tissue and elicit a desmoplastic Tumor with this configuration are termed as atypical, invasive or aggressive pilomatricoma. These tumors have increased risk of recurrence.
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Melanization of tumor cells can alos oocur.
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Differential diagnosis-Pilar basal cell carcinoma.
References
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James W. Patterson, Mark R. Wick. Nonmelanocytic tumors of the skin. AFIP Atlas of tumor pathology. Series 4.
Pilomatricoma: Tumor showing basophilic tumor cells (left side) and ghost cells (right side). Interstitial fibrocollagenous tissue with chronic inflammatory cells (H&E,X100)
Pilomatricoma: Tumor showing basophilic tumor cells (left side) and ghost cells (right side) (H&E,X400)
Pilomatricoma: Basophilic monotonous tumor cells having round nuclei with nucleoli (H&E,X400)
Pilomatricoma: Ghost cells surrounded by foreign body giant cells and chronic inflammatory cells. Foci of calcification is present (left bottom) (H&E, X100)
Pilomatricoma: Monotonous basophilic cells and ghost cells (left side) with adjacent fibrocollagenous tissue showing chronic inflammatory cells and foci of calcification (H&E, X100)
Pilomatricoma: Sheets of monotonous basophilic tumor cells and ghost cells. Interstitial stroma shows multinucleated foreign body giant cells and chronic inflammatory cells (H&E,X100)
Pilomatricoma: Tumor is composed of basophilic cells phasing into eosinophilic ghost cells. Adjacent fibrocollagenous stroma shows chronic inflammatory cells and multinucleated giant cells (H&E,X50)
Pilomatricoma: Tumor is composed of basophilic cells phasing into eosinophilic ghost cells. Adjacent fibrocollagenous stroma shows chronic inflammatory cells (H&E,X100)
Pilomatricoma: Tumor with lobules of basophilic cells. Adjacent fibrocollagenous stroma shows chronic inflammatory cells (H&E,X50)
Pilomatricoma: Tumor with lobules of monotonous basophilic cells (H&E,X100)
Pilomatricoma: Tumor showing basophilic tumor cells phasing into eosinophilic ghost cells surrounded by fibrocollagenous tissue with chronic inflammatory cells and multinucleated giant cells (H&E,X50)
Pilomatricoma: Tumor showing basophilic tumor cells (right side) and ghost cells (left side). Interstitial fibrocollagenous tissue with chronic inflammatory cells (H&E,X100)
Pilomatricoma: Tumor with sheets of monotonous basophilic cells with round nuclei. Adjacent fibrocollagenous tissue shows congested blood vessels (H&E,X100)
Pilomatricoma: Basophilic monotonous tumor cells having round nuclei with nucleoli (H&E,X400)
Pilomatricoma: Tumor with basophilic cells phasing out into eosinophilic ghost cells with washed out nuclei (H&E,X50)
Pilomatricoma: Tumor with basophilic cells phasing out into eosinophilic ghost cells with washed out nuclei (H&E,X400)
Pilomatricoma: Tumor with basophilic cells phasing out into eosinophilic ghost cells with washed out nuclei (H&E,X400)
Pilomatricoma: Tumor with eosinophilic ghost cells having washed out nuclei (H&E,X400)
Pilomatricoma: Tumor with eosinophilic ghost cells having washed out nuclei (H&E,X400)
Pilomatricoma: Tumor with eosinophilic ghost cells having washed out nuclei (H&E,X400)
Pilomatricoma: Tumor with eosinophilic ghost cells surrounded by multinucleated foreign body giant cells (H&E,X100)
Pilomatricoma: Tumor with eosinophilic ghost cells surrounded by multinucleated foreign body giant cells (H&E,X100)
Pilomatricoma: Tumor with eosinophilic ghost cells surrounded by multinucleated foreign body giant cells (H&E,X200)
Pilomatricoma: Tumor with eosinophilic ghost cells surrounded by multinucleated foreign body giant cells (H&E,X400)
Pilomatricoma: Eosinophilic ghost cells with areas ofcalcification. Adjacent fibrocollagenous tissue shows chronic inflammatory cells (H&E,X100)
Pilomatricoma: Eosinophilic ghost cells with areas ofcalcification. Adjacent fibrocollagenous tissue shows chronic inflammatory cells and foriegn body giant cells (H&E,X100)
Pilomatricoma: Eosinophilic ghost cells with areas ofcalcification. Adjacent fibrocollagenous tissue shows chronic inflammatory cells (H&E,X100)