View the images and select the correct diagnosis from the list below.
FNAB of a painless parotid lesion with a recent rapid increase in size, present for approximately eight years in a 40-year-old man:
Select one of the following:
You answered: Pleomorphic Adenoma.
Sorry, that is Incorrect.
The correct answer is: Schwannoma.
- 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
- 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 referred 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
- Demay R.M.
The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.
- Faquin W.C., Powers C.N.
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 G.T.
Diagnostic Cytopathology. 2nd Edition. Elsevier Science Limited 2003; 311, 884-896.
You answered: Schwannoma
Correct!!
- 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
- 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 referred 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
- Demay R.M.
The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.
- Faquin W.C., Powers C.N.
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 G.T.
Diagnostic Cytopathology. 2nd Edition. Elsevier Science Limited 2003; 311, 884-896.
You answered: Nodular fasciitis
Sorry, that is Incorrect
The correct answer is: Schwannoma
- 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
- 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 referred 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
- Demay R.M.
The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.
- Faquin W.C., Powers C.N.
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 G.T.
Diagnostic Cytopathology. 2nd Edition. Elsevier Science Limited 2003; 311, 884-896.
You answered: Myoepithelioma
Sorry, that is Incorrect
The correct answer is: Schwannoma
- 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
- 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 referred 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
- Demay R.M.
The Art & Science of Cytopathology: Chicago: ASCP Press, 1996; 585-587, 669-673.
- Faquin W.C., Powers C.N.
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 G.T.
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.
