An introduction to head and neck pathology

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Head and neck pathology is squamous cell carcinoma and weird stuff. The thyroid is dealt with in its own article, as is pathology of the salivary gland.

Oral lesions

Clinical:[1]

  • Leukoplakia.
    • Unidentified white lesion.
    • More worrisome than erythroplakia.
    • Often assoc. with epithelial thickening (hyperkeratosis, acanthosis).
  • Erythroplakia.
    • Unidentified red lesion.
    • Often erosion.

Pyogenic granuloma

  • Sometimes pregnancy tumour.
  • Seen in children, young adults, pregnant women.

Histology[2]

  • Vascular.
  • Peduncular lesion.

Gross[3]

  • Erythematous.
  • Hemorrhagic.

DDx:

  • Capillary hemangioma.


Hairy leukoplakia

Features:[4]

  • Oral lesion.
  • Often on tongue.
  • Thought to be caused by EBV.

Gross:

  • White confluent patches (icing sugar).

Microscopic: Features:[5]

  • Hyperkeratosis (thicker stratum corneum).[6]
  • Acanthosis (thicker stratum spinosum).[7]
  • "Balloon cells" in upper stratum spinosum - perinuclear clearing.


Plummer-Vinson syndrome

Triad:[8]

  • Iron-deficiency anemia.
  • Glossitis.
  • Esophageal dysphagia (usually related to webs).


Oral candidiasis

  • Fungus.
  • May be assoc. with immunodeficiency, e.g. AIDS.

Forms:[9]

  • Pseudomembranous (thrush).
  • Erythematous.
  • Hyperplastic.

Tonsillar lymphangiomatous polyps

Features:[10]

  • Polyp with lymph channels.


Pharyngeal carcinoma/nasopharyngeal carcinoma

  • Specimens may be challenging to interpret as there is normally an abundance of lymphoid cells.
  • Malignant tissue can look benign.[11].
  • May be difficult to differentiate from other malignancies.

Histology

  • Upper airway distant from areas with friction: respiratory type epithelium.

Work-up of negative H&E Bx differs by site:

Classification

SCC is subdivided by the WHO into:[13]

  • Keratinizing type (KT).
    • Worst prognosis.
  • Undifferentiated type (UT).
    • Intermediate prognosis.
    • EBV association.
  • Nonkeratinizing type (NT).
    • Good prognosis.
    • EBV association.

Histology of SCC

Features:[14]

  • KT subtype:
    • Keratinization & intercellular bridges through-out most of the malignant lesion.
  • UT:
    • Non-distinct borders/syncytial pattern.
    • Nucleoli.
  • NT:
    • Well-defined cell borders.

Squamous lesions

  • Premalignant lesions
    • Mild dysplasia.
      • Low risk of progression to invasive lesions.
    • Moderate dysplasia.
    • Severe dysplasia/carcinoma in situ (CIS).
      • Histologically severe dysplasia and CIS cannot be differentiated reliably; ergo, there can be considered the same thing.
      • Severe dysplasia is not a necessary intermediate for cancer, i.e. invasive squamous cell carcinoma may be present with moderate dysplasia.
  • Invasive squamous cell carcinoma (SCC).
    • "Microinvasive" squamous cell carcinoma - term should be avoided as there is no concenus on what it means.
    • There are several subtypes of SCC.

Squamous cell carcinoma

Microscopy

Invasive cancer look for:

  • Eosinophilia.
  • Extra large nuclei/bizarre nuclei.
  • Inflammation (lymphocytes, plasma cells).
  • Long rete ridges.
  • Numerous beeds/blobs of epithelial cells that seem unlikely to be rete ridges.

Pitfalls:

  • Tangential cuts.
    • If you can trace the squamous cells from a gland to the surface it is less likely to be invasive cancer.

Notes on invasion:

Overview of subtypes

There are several subtypes:[16]

  • Basaloid - poor prognosis, usu. diagnosed by recognition of typical SCC.
  • Warty (Condylomatous).
  • Verrucous - good prognosis, rare.
  • Papillary.
  • Lymphoepithelial, rare.
  • Spindle cell, a common spindle cell lesion of the H&N.


Verrucous squamous cell carcinoma

Features:

  • Exophytic growth.
  • Well-differentiated.
  • "Glassy" appearance.
  • Pushing border.

DDx: papilloma.

Spindle cell squamous carcinoma

  • Key to diagnosis is finding a component of conventional squamous cell carcinoma.

IHC:

  • Typically keratin -ve.
  • p63 +ve.

DDx:

  • Spindle cell melanoma.
  • Mesenchymal neoplasm.

Basaloid squamous cell carcinoma

  • May mimic adenoid cystic carcinoma.
  • Classically base of tongue.[17]
  • Typically poor prognosis.

Features:

  • Need keratinization. (???)

DDx:

  • Neuroendocrine tumour.

Lymphoepithelial (squamous cell) carcinoma

  • Rare.
  • +/-EBV.

Small cell anaplastic carcinoma

  • Rare.

DDx:

  • Metastatic small cell carcinoma of the lung.

Granular cell tumour

  • May mimic (well-differentiated) squamous cell carcinoma - histopathologically.
  • Usually a benign tumour.

Features:

  • Large polygonal cells with abundant (eosinophilic) granular cytoplasm.

Image:

Ameloblastoma

  • Osteous lesion.

Features:[18]

  • Stellate reticulum - star-shaped cells, found in a developing tooth.[19]
  • Tall columnar cells.
    • Nuclei distant from the basement membrane (reverse polarization of the nuclei).
  • +/-Giant cells.

Images:

Nasal polyps

DDx (benign - multiple):[20]

  • Autoimmune/idiopathic:
    • Asthma.
    • Allergic rhinitis.
    • Churg-Strauss syndrome (AKA allergic granulomatous angiitis) - considered a type of Polyarteritis nodosa (PAN).
      • Features: asthma, eosinophilia, granulomatous inflammation, necrotizing systemic vasculitis, and necrotizing glomerulonephritis.[21]
    • Nonallergic rhinitis with eosinophilia syndrome (NARES).
  • Infectious:
    • Fungal infection (with allergic component - AFS = allergic fungal sinusitis).
    • Chronic rhinosinusitis.
  • Genetic
    • Primary ciliary dyskinesia.
    • Cystic fibrosis.
  • Associations:
    • Alcohol intolerance ~ 50%.
    • Aspirin intolerance - upto ~ 25%.

Tumours:

  • Juvenile nasopharyngeal angiofibroma (young males).
  • Nasopharyngeal carcinomas.
  • Sarcomas.
  • Hemangioma.
  • Papilloma.
  • Other.

Epidemiology

  • More commonly assoc. with nonallergic conditions.[20]

Treatment

  • Recurrent polyps: Functional endoscopic sinus surgery (FESS).

See also

References

External links