HEAD AND NECK PATHOLOGY

CHAPTER 3 HEAD AND NECK PATHOLOGY





Malignant peripheral nerve sheath tumor

Olfactory neuroblastoma (esthesioneuroblastoma)

Melanotic neuroectodermal tumor of infancy

Ectomesenchymoma

Nasal glial heterotopia

Nasopharyngeal carcinoma

Nasal / choanal polyps

Hairy polyp of the nasopharynx

Salivary gland anlage tumor (congenital pleomorphic adenoma)

Chondromesenchymal hamartoma

(Juvenile) nasopharyngeal angiofibroma

Juvenile laryngeal papillomatosis

Laryngeal hemangioma

Laryngeal granular cell tumour

Cholesteatoma

Thyroid disorders
Thyroid carcinoma (excluding medullary carcinoma)

Papillary carcinoma of thyroid

Follicular carcinoma of thyroid

Medullary thyroid carcinoma

Thyroid c-cell hyperplasia

Spindle cell tumor with thymus-like differentiation (SETTLE)

Oral lesions

Ectomesenchymal chondromyxoid tumor of the anterior tongue

Focal oral mucinosis

Congenital granular cell epulis (granular cell tumor)

Salivary gland tumors
Pleomorphic adenoma

Acinic cell carcinoma

Mucoepidermoid carcinoma

Adenoid cystic carcinoma

Sialoblastoma

Salivary gland hemangioma

Odontogenic tumors

Other lesions

Ossifying fibroma

Central giant cell lesion

Dermoid cyst

Branchial cleft remnants

Thyroglossal duct remnants



INTRODUCTION



• Many head and neck lesions are covered elsewhere in other sections, such as soft tissue tumors

• Detailed here are only entities either specific to, or much more common in, this area, or in which there are specific issues when such entities occur in the head and neck


MALIGNANT PERIPHERAL NERVE SHEATH TUMOR



Epidemiology



• Usually NF1 associated when occurs in childhood

• In patients with NF-1
image MPNST diagnosed in childhood at average age 12 years
– can rarely occur in infancy (Friedrich et al 2007)


Clinical features



• Solid infiltrative lesion

• Presentation according to site

• MPNST arising from enlarging plexiform neurofibromas
image present with pain / neurological impairment


Histopathological features (Figs 3.1–3.3)



• Spindle (majority) and/or epithelioid variants

• Plump fusiform cells

• Variably cellular

• <5% MPNST may show perineurial differentiation
image long slender processes
– EMA+, S100−

image better prognosis, less associated with NF-1 (Hirose et al 1998)

image

Fig 3.1 Photograph of a case of malignant peripheral nerve sheath tumor in an adolescent with known neurofibromatosis.


image

Fig. 3.2


image

Figs 3.2–3.3 Photomicrographs of a case of malignant peripheral nerve sheath tumor in an adolescent with known neurofibromatosis, demonstrating an infiltrative spindle cell lesion, which focally expressed neural markers.



Immunohistochemical staining



• Focal S100+

• Focal GFAP / PGP+


Differential diagnoses and pitfalls



• Cellular Schwannoma may look similar but:
image diffuse S100+

image encapsulated


OLFACTORY NEUROBLASTOMA (ESTHESIONEUROBLASTOMA)



Epidemiology



• Peak in 2nd decade in childhood but all ages


Clinical features



• Nasal obstruction and/or epistaxis


Histopathological features (Figs 3.4, 3.5)



• Lobules and nests of tumor cells within a vascular stroma

• Nests of uniform round to ovoid cells
image neurofibrillary matrix

image neural rosettes

• Grade I (well differentiated) – grade IV (undifferentiated / anaplastic)

image

Fig. 3.4


image

Figs 3.4–3.5 Photomicrographs of a case of olfactory neuroblastoma, showing monotonous nests and sheets of uniform ovoid cells in a subepithelial location.



Immunohistochemical staining



• NSE+ tumor cells (± chromogranin, synaptophysin etc)

• S100+ peripheral sustentacular cells

• CK, CD99−


Electron microscopy



• Dense core neurosecretory granules


Differential diagnoses and pitfalls



• Olfactory neuroblastomas lack the EWS/FLI1 fusion and are genetically unrelated to PNET

• However, PNET may also rarely occur as primary sinonasal tumor (Kumar et al 1999)


MELANOTIC NEUROECTODERMAL TUMOR OF INFANCY



Epidemiology



• Infants


Clinical features



• Majority (90%) in craniofacial region
image especially maxilla

• Pigmented enlarging mass

• VMA elevated in a minority

• 5% metastases

• Local recurrence in one-third (Fowler et al 2006)


Histopathological features (Figs 3.6–3.11)



• Poorly circumscribed infiltrative and unencapsulated lesion

• Dual population of cell types
image large epithelioid pigmented cells
– CK, HMB45+

image small neuroblast like cells
– NSE, CD56+

image variably collagenous fibrous stroma

• No reliable histopathological or molecular features to predict the biological behavior in individual cases (Fowler et al 2006)

image

Fig 3.6 Photograph of a case of melanotic neuroectodermal tumor of infancy, demonstrating an intraosseous lesion with areas of black (melanin) pigmentation seen on macroscopic examination.


image

Fig. 3.7


image

Fig. 3.8


image

Fig. 3.9


image

Figs 3.7–3.10 Photomicrographs of cases of melanotic neuroectodermal tumor of infancy, demonstrating an infiltrative lesion composed of a dual population of cells within a fibrous stroma; large, epithelioid pigmented melanocyte-like cells and smaller nests of neuroblastoma-like cells.


image

Fig 3.11 Photomicrograph of a case of melanotic neuroectodermal tumor of infancy, demonstrating the larger cells to immunostain with HMB45.



Differential diagnoses and pitfalls



• Core needle biopsy may demonstrate only the small cell component!
image clinicopathological correlation required in this setting


ECTOMESENCHYMOMA



• Tumor derived from pluripotent primitive neural crest cells with mixed pathways of differentiation


Epidemiology



• Usually young children, including infants


Clinical features



• Local mass lesion, usually head and neck or pelvis or perineum

• Behavior essentially as RMS


Histopathological features



• Admixed neural and other mesenchymal tissues:
image mesenchymal elements usually eRMS (Mouton et al 1996)

image admixed neural elements
– neuroblasts

– ganglion cells

– melanocytes

• Neural tissue usually neuroblastic differentiation with ganglion cells in an otherwise classic embryonal rhabdomyosarcoma


Immunohistochemical staining



• Focal expression of neural and other mesenchymal markers


Differential diagnoses and pitfalls



• May histologically appear as rhabdomyosarcoma with focal neural areas

• May only show neural elements in recurrence or metastasis of ‘RMS’ (Sebire et al 2003, Floris et al 2007)

• Microarray analyses shows clustering most closely with MPNST (Kleinschmidt-DeMasters et al 2007)


NASAL GLIAL HETEROTOPIA



Epidemiology



• Birth or first few years of life


Clinical features



• Nasal / paranasal mass
image nasal cavity – majority

image nasal bridge (Penner & Thompson 2003)

• Rarely sinuses or parapharyngeal sites

• No intracranial component or bony defect

• May also occur in nasopharynx and may rarely be associated with facial clefts


Histopathological features (Figs 3.12–3.14)



• Unencapsulated lesion composed of:
image islands of astrocytes and neuroglial fibers

image admixed with variable amounts of fibrovascular connective tissue stroma

• Glial component may be subtle in some cases on initial H&E staining
image glial fibrillary acidic protein (GFAP) staining diagnostic

image

Fig. 3.12


image

Figs 3.12–3.13 Photomicrographs of a case of nasal glial heterotopia, demonstrating an unencapsulated lesion composed of islands of astrocytes and neuroglial fibers admixed with variable amounts of fibrovascular connective tissue stroma.


image

Fig 3.14 Photomicrograph of a case of nasal glial heterotopia, demonstrating strong glial positivity on immunostaining for GFAP.



Immunohistochemical staining



• GFAP+


Differential diagnoses and pitfalls



• Encephalocele
image communicates with an intracranial component via a bony defect


NASOPHARYNGEAL CARCINOMA



Epidemiology



• Usually males 40–60 years of East Asian origin
image occurs rarely but is well-reported in childhood

• Most are EBV-related


Clinical features



• Local disease
image nasal obstruction / discharge

image Eustachian tube blockage

• Metastatic disease

• >80% overall survival in this age group (Cannon et al 2006)


Histopathological features



• Several histological subtypes
image nonkeratinizing
– nests and syncytial like sheets of squamoid / epithelioid cells in lymphoid-rich stroma

– undifferentiated subtype
· large cells with vesicular nuclei and prominent nucleoli

image keratinizing
– nests of cells with morphology of invasive squamous cell carcinoma


Immunohistochemical staining



• MNF116 and p63 uniform positivity

• EBER + ISH
image almost all EBER+ in non-keratinizing subtype

image focal EBER+ in keratinizing subtype

• c-Kit (CD117)+ in 90% (Bar-Sela et al 2005)

• Heparanase expression inversely associated with survival (Bar-Sela et al 2005)

• Stromal CD10 expression
image associated with adverse prognosis (Braham et al 2006)


Differential diagnoses and pitfalls



• Amount of lymphoid stroma may vary from almost none to extensive
image can mimic lymphoma

• Most childhood cases are nonkeratinizing type


NASAL / CHOANAL POLYPS



• May occur but generally rare in childhood
image if present, consider underlying conditions:
– Kartagener’s syndrome

– cystic fibrosis (CF)

• Polypoid lesions (Fig 3.15)
image covered by respiratory epithelium

image underlying edematous stroma

image thickened basement membrane

image mixed inflammatory cell infiltrate, including eosinophils

• Polyps in CF
image may be complicated by fungal infection

image show dilated glands containing eosinophilic inspissated material

image less eosinophils and basement membrane thickening than allergic type

image

Fig 3.15 Photomicrograph of a case of an inflammatory / allergic nasal polyp in a child with cystic fibrosis. The polyp is covered by respiratory epithelium with underlying edematous stroma containing a mixed inflammatory infiltrate, and there is a dilated gland containing eosinophilic inspissated material.



HAIRY POLYP OF THE NASOPHARYNX



• Infants

• F > M

• Mass affecting nasopharynx, palate or middle ear (Kieff et al 1998, Chang et al 2007)
image also rarely reported in association with facial cleft

• Polypoid lesion covered with skin (Fig 3.16)
image contains pilosebaceous units

• Fibrofatty core
image may contain cartilage, bone or muscle

• No elements from other germ cell layers cf true teratoma

image

Fig 3.16 Photomicrograph of a hairy polyp of the nasopharynx, demonstrating a fibrofatty core, in this case also containing cartilage, covered by skin with end-all structures.



SALIVARY GLAND ANLAGE TUMOR (CONGENITAL PLEOMORPHIC ADENOMA)



• Infants, usually present at birth

• M > F

• Benign
image curative excision

• Midline polypoid lesion
image nonkeratinizing squamous epithelium

image stroma with nodules of fusiform cells

image tubule formation

image ducts

• Bland nuclei

• Vimentin, CK and SMA+


CHONDROMESENCHYMAL HAMARTOMA



• Intranasal mass in an infant

• Two histological elements:
image myxoid to spindle cell stroma

image nodules of mature cartilage


(JUVENILE) NASOPHARYNGEAL ANGIOFIBROMA



Epidemiology



• Males

• First three decades
image peak in second decade

• Exclude testicular feminization syndrome if occurs in a phenotypically female patient

• Most are sporadic
image increased frequency in patients with familial adenomatous polyposis


Clinical features



• Nasopharyngeal mass with local infiltration
image extensive involvement in one-third

• Nasal obstruction

• Epistaxis

• Other local symptoms

• 20% local recurrence


Histopathological features (Figs 3.17–3.21)



• Numerous predominantly thin-walled vessels
image bland endothelium

• Variably fibrous stroma
image plump spindle to stellate cells

• Lesions become increasingly fibrotic and less vascular with maturity

• Therapeutic embolization may be associated with secondary changes

image

Fig. 3.17


image

Fig. 3.18


image

Figs 3.17–3.19

Related posts:

  1. METABOLIC DISEASE PATHOLOGY
  2. BONE PATHOLOGY
  3. RENAL PATHOLOGY
  4. TUMORS AND TUMOR-LIKE LESIONS

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Jun 18, 2016 | Posted by in PEDIATRICS | Comments Off on HEAD AND NECK PATHOLOGY

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