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Case 14

View the images and select the correct diagnosis from the list below.

"It ain't no smyelin' matter"

FNAB of a painless parotid lesion with a recent rapid increase in size, present for approximately eight years in a 40-year-old man:

Image 1 

Image 2 

Image 3 

Image 4 

Select one of the following:

 

You answered: Pleomorphic Adenoma
Sorry, that is INCORRECT


The correct answer is: Schwannoma 


Cytopathology:

  • The smears reveal loose clusters of cells in a myxoid background
  • The cells are oval and spindle-shaped; some have slightly bent nuclei
  • There is moderate variation in nuclear size and shape. Some nuclear palisading is noted

Discussion:

  • Schwannoma, also known as neurilemoma, is a benign, encapsulated tumour of Schwann cells found throughout the peripheral nervous system. They are commonly found in the head and neck region
  • Aspiration biopsy is often unusually painful
  • Treatment is simple surgical excision
  • Tumour cells strongly express S100 protein and vimentin
  • Histologically, schwannomas often have cellular and less cellular areas refered to as Antoni A and Antoni B areas respectively
    • Antoni A areas may contain regions of bundles of spindle shaped Schwann cells with palisading nuclei surrounding a central fibrillar core known as Verocay bodies (not present in this case)
    • Antoni B areas contain few randomly arranged Schwann cells within loose myxoid stroma
  • Cytologic differential diagnosis:
    • Pleomorphic adenoma may be suggested by the myxoid stroma and spindle cells. Confident diagnosis of PA requires identification of epithelial and/or myoepithelial cells in a metachromatic, usually fibrillar, stroma
    • Nodular fasciitis may have spindle cells and myxoid stroma. A history of rapid growth is usually noted. Unlike Schwannoma the bland appearing spindle cells have wispy bipolar cytoplasmic processes and tend not to form Antoni A and B areas. Often a background of chronic inflammation is present
    • The spindle cell variant of myoepithelioma may mimic Schwannoma but does not usually have a significant stromal component.

Back to images


Histology


References:

Demay RM. The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.

Faquin WC, Powers CN. Cytologic Evaluation of Salivary Gland Aspirates: A Case-Based Approach with Histologic Correlation. American Society of Cytopathology 53rd Annual Scientific Meeting. San Diego, CA, November 4-9, 2005.

Gray W, McKee GT. Diagnostic Cytopathology. 2nd Edition. Elesevier Science Limited 2003; 311, 884-896.

You answered: Schwannoma 


CORRECT!!


Cytopathology:

  • The smears reveal loose clusters of cells in a myxoid background
  • The cells are oval and spindle-shaped; some have slightly bent nuclei
  • There is moderate variation in nuclear size and shape. Some nuclear palisading is noted

Discussion:

  • Schwannoma, also known as neurilemoma, is a benign, encapsulated tumour of Schwann cells found throughout the peripheral nervous system. They are commonly found in the head and neck region
  • Aspiration biopsy is often unusually painful
  • Treatment is simple surgical excision
  • Tumour cells strongly express S100 protein and vimentin
  • Histologically, schwannomas often have cellular and less cellular areas refered to as Antoni A and Antoni B areas respectively
    • Antoni A areas may contain regions of bundles of spindle shaped Schwann cells with palisading nuclei surrounding a central fibrillar core known as Verocay bodies (not present in this case)
    • Antoni B areas contain few randomly arranged Schwann cells within loose myxoid stroma
  • Cytologic differential diagnosis:
    • Pleomorphic adenoma may be suggested by the myxoid stroma and spindle cells. Confident diagnosis of PA requires identification of epithelial and/or myoepithelial cells in a metachromatic, usually fibrillar, stroma
    • Nodular fasciitis may have spindle cells and myxoid stroma. A history of rapid growth is usually noted. Unlike Schwannoma the bland appearing spindle cells have wispy bipolar cytoplasmic processes and tend not to form Antoni A and B areas. Often a background of chronic inflammation is present
    • The spindle cell variant of myoepithelioma may mimic Schwannoma but does not usually have a significant stromal component

Back to Images


Histology


References:

Demay RM. The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.

Faquin WC, Powers CN. Cytologic Evaluation of Salivary Gland Aspirates: A Case-Based Approach with Histologic Correlation. American Society of Cytopathology 53rd Annual Scientific Meeting. San Diego, CA, November 4-9, 2005.

Gray W, McKee GT. Diagnostic Cytopathology. 2nd Edition. Elsevier Science Limited 2003; 311, 884-896.

You answered: Nodular Fasciitis
Sorry, that is INCORRECT 


The correct answer is: Schwannoma


Cytopathology:

  • The smears reveal loose clusters of cells in a myxoid background
  • The cells are oval and spindle-shaped; some have slightly bent nuclei
  • There is moderate variation in nuclear size and shape. Some nuclear palisading is noted

Discussion:

  • Schwannoma, also known as neurilemoma, is a benign, encapsulated tumour of Schwann cells found throughout the peripheral nervous system. They are commonly found in the head and neck region
  • Aspiration biopsy is often unusually painful
  • Treatment is simple surgical excision
  • Tumour cells strongly express S100 protein and vimentin
  • Histologically, Schwannomas often have cellular and less cellular areas refered to as Antoni A and Antoni B areas respectively
    • Antoni A areas may contain regions of bundles of spindle shaped Schwann cells with palisading nuclei surrounding a central fibrillar core known as Verocay bodies (not present in this case)
    • Antoni B areas contain few randomly arranged Schwann cells within loose myxoid stroma
  • Cytologic differential diagnosis:
    • Pleomorphic adenoma may be suggested by the myxoid stroma and spindle cells. Confident diagnosis of PA requires identification of epithelial and/or myoepithelial cells in a metachromatic, usually fibrillar, stroma
    • Nodular fasciitis may have spindle cells and myxoid stroma. A history of rapid growth is usually noted. Unlike Schwannoma the bland appearing spindle cells have wispy bipolar cytoplasmic processes and tend not to form Antoni A and B areas. Often a background of chronic inflammation is present
    • The spindle cell variant of myoepithelioma may mimic Schwannoma but does not usually have a significant stromal component

Back to Images


Histology


References:

Demay RM. The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.

Faquin WC, Powers CN. Cytologic Evaluation of Salivary Gland Aspirates: A Case-Based Approach with Histologic Correlation. American Society of Cytopathology 53rd Annual Scientific Meeting. San Diego, CA, November 4-9, 2005.

Gray W, McKee GT. Diagnostic Cytopathology. 2nd Edition. Elsevier Science Limited 2003; 311, 884-896.

You answered: Myoepithelioma
Sorry, that is INCORRECT 


The correct answer is: Schwannoma


Cytopathology:

  • The smears reveal loose clusters of cells in a myxoid background
  • The cells are oval and spindle-shaped; some have slightly bent nuclei
  • There is moderate variation in nuclear size and shape. Some nuclear palisading is noted

Discussion:

  • Schwannoma, also known as neurilemoma, is a benign, encapsulated tumour of Schwann cells found throughout the peripheral nervous system. They are commonly found in the head and neck region
  • Aspiration biopsy is often unusually painful
  • Treatment is simple surgical excision
  • Tumour cells strongly express S100 protein and vimentin
  • Histologically, schwannomas often have cellular and less cellular areas refered to as Antoni A and Antoni B areas respectively
    • Antoni A areas may contain regions of bundles of spindle shaped Schwann cells with palisading nuclei surrounding a central fibrillar core known as Verocay bodies (not present in this case)
    • Antoni B areas contain few randomly arranged Schwann cells within loose myxoid stroma
  • Cytologic differential diagnosis:
    • Pleomorphic adenoma may be suggested by the myxoid stroma and spindle cells. Confident diagnosis of PA requires identification of epithelial and/or myoepithelial cells in a metachromatic, usually fibrillar, stroma
    • Nodular fasciitis may have spindle cells and myxoid stroma. A history of rapid growth is usually noted. Unlike Schwannoma the bland appearing spindle cells have wispy bipolar cytoplasmic processes and tend not to form Antoni A and B areas. Often a background of chronic inflammation is present
    • The spindle cell variant of myoepithelioma may mimic Schwannoma but does not usually have a significant stromal component

Back to Images


Histology


References:

Demay RM. The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.

Faquin WC, Powers CN. Cytologic Evaluation of Salivary Gland Aspirates: A Case-Based Approach with Histologic Correlation. American Society of Cytopathology 53rd Annual Scientific Meeting. San Diego, CA, November 4-9, 2005.

Gray W, McKee GT. Diagnostic Cytopathology. 2nd Edition. Elsevier Science Limited 2003; 311, 884-896.


 

From the Cytopathology files of BC Cancer

Submitted by: Amanda Reith, BSc; edited by Brenda Smith, BSc and Tom Thomson, MD


SOURCE: Case 14 ( )
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