Difference between revisions of "An introduction to head and neck pathology"

Jump to navigation Jump to search
 
(21 intermediate revisions by the same user not shown)
Line 1: Line 1:
'''Head and neck pathology''' is squamous cell carcinoma and weird stuff.   
This article is '''an introduction to head and neck pathology'''. Most of head and neck pathology is squamous cell carcinoma and its variants.   


The [[thyroid gland]] is dealt with in its own article, as is pathology of the [[salivary gland]].
The [[thyroid gland]] is dealt with in its own article, as is pathology of the [[salivary gland]].


Cytopathology of the head and neck is dealt with in a separate article called ''[[head and neck cytopathology]]''.
Cytopathology of the head and neck is dealt with in a separate article called ''[[head and neck cytopathology]]''.
=Anatomy=
[[Image:Blausen_0872_UpperRespiratorySystem.png|thumb|Head and neck anatomy (BruceBlaus/WC).]]
*Oropharynx - includes: tonsil, tonsillar pillar, base of tongue, soft palate.<ref>URL: [https://www.cancer.org/cancer/oral-cavity-and-oropharyngeal-cancer/about/what-is-oral-cavity-cancer.html https://www.cancer.org/cancer/oral-cavity-and-oropharyngeal-cancer/about/what-is-oral-cavity-cancer.html]. Accessed on: 1 April 2021.</ref><ref>URL: [http://www.headandneckcancerguide.org/teens/cancer-basics/explore-cancer-types/throat-cancer/oropharyngeal-cancer/soft-palate-cancer/ http://www.headandneckcancerguide.org/teens/cancer-basics/explore-cancer-types/throat-cancer/oropharyngeal-cancer/soft-palate-cancer/]. Accessed on: 15 November 2016.</ref>
*Oral cavity - includes floor of mouth, bucca, anterior 2/3 of tongue,<ref>URL: [http://www.headandneckcancerguide.org/teens/cancer-basics/explore-cancer-types/oral-cancers/tongue-cancer/ http://www.headandneckcancerguide.org/teens/cancer-basics/explore-cancer-types/oral-cancers/tongue-cancer/]. Accessed on: 15 November 2016.</ref> lips, [[hard palate]], upper & lower alveolar ridge, retromolar trigone.<ref>URL: [http://www.headandneckcancerguide.org/teens/cancer-basics/explore-cancer-types/oral-cancers/oromandibular-cancer/ http://www.headandneckcancerguide.org/teens/cancer-basics/explore-cancer-types/oral-cancers/oromandibular-cancer/]. Accessed on: 15 November 2016.</ref>
*Laryngopharynx.
*Nasopharynx.


=Clinical=
=Clinical=
Common lesions:<ref name=Ref_PBoD780>{{Ref PBoD|780}}</ref>
Common lesions:<ref name=Ref_PBoD780>{{Ref PBoD|780}}</ref>
*Leukoplakia.
*[[Leukoplakia]].
**Homogeneous.
**Homogeneous.
**Non-homogeneous.
**Non-homogeneous.
Line 15: Line 22:
:''[[Hairy leukoplakia]] is dealt with in a separate section''.
:''[[Hairy leukoplakia]] is dealt with in a separate section''.
:''The typical [[benign leukoplakia]] is dealt with in a separate section''.
:''The typical [[benign leukoplakia]] is dealt with in a separate section''.
 
{{Main|Leukoplakia}}
===General===
*Non-specific clinical finding - may be benign ''or'' malignant.
*Associated with tobacco use.<ref name=pmid11336117>{{Cite journal  | last1 = Bánóczy | first1 = J. | last2 = Gintner | first2 = Z. | last3 = Dombi | first3 = C. | title = Tobacco use and oral leukoplakia. | journal = J Dent Educ | volume = 65 | issue = 4 | pages = 322-7 | month = Apr | year = 2001 | doi =  | PMID = 11336117 }}</ref>
 
Risk of malignancy:
*In twos series ~13% were associated with an invasive lesion.<ref name=pmid19953947>{{Cite journal  | last1 = Lan | first1 = AX. | last2 = Guan | first2 = XB. | last3 = Sun | first3 = Z. | title = [Analysis of risk factors for carcinogenesis of oral leukoplakia]. | journal = Zhonghua Kou Qiang Yi Xue Za Zhi | volume = 44 | issue = 6 | pages = 327-31 | month = Jun | year = 2009 | doi =  | PMID = 19953947 }}</ref><ref name=pmid16545712>{{Cite journal  | last1 = Lee | first1 = JJ. | last2 = Hung | first2 = HC. | last3 = Cheng | first3 = SJ. | last4 = Chen | first4 = YJ. | last5 = Chiang | first5 = CP. | last6 = Liu | first6 = BY. | last7 = Jeng | first7 = JH. | last8 = Chang | first8 = HH. | last9 = Kuo | first9 = YS. | title = Carcinoma and dysplasia in oral leukoplakias in Taiwan: prevalence and risk factors. | journal = Oral Surg Oral Med Oral Pathol Oral Radiol Endod | volume = 101 | issue = 4 | pages = 472-80 | month = Apr | year = 2006 | doi = 10.1016/j.tripleo.2005.07.024 | PMID = 16545712 }}</ref>
*Non-homogenous leukoplakia has a greater risk of malignancy than homogenous.<ref name=pmid16545712/>
*Location matters - floor of mouth and ventral tongue lesions higher risk for malignancy.<ref name=pmid7548621>{{Cite journal  | last1 = Sciubba | first1 = JJ. | title = Oral leukoplakia. | journal = Crit Rev Oral Biol Med | volume = 6 | issue = 2 | pages = 147-60 | month =  | year = 1995 | doi =  | PMID = 7548621 | URL = http://cro.sagepub.com/content/6/2/147.long }}</ref>
 
===Gross===
*White lesion - may be subdivided:
**Non-homogenous.
**Homogenous.
 
===Microscopic===
Features:<ref name=Ref_PBoD780>{{Ref PBoD|780}}</ref>
*Often associated with epithelial thickening ([[hyperkeratosis]], [[acanthosis]]).
 
DDx:
*Food debris.
*[[Oral candidiasis]].
*[[Lichen planus]].
*[[Benign alveolar ridge keratosis]] (oral [[lichen simplex chronicus]]).<ref name=pmid18158926>{{Cite journal  | last1 = Natarajan | first1 = E. | last2 = Woo | first2 = SB. | title = Benign alveolar ridge keratosis (oral lichen simplex chronicus): A distinct clinicopathologic entity. | journal = J Am Acad Dermatol | volume = 58 | issue = 1 | pages = 151-7 | month = Jan | year = 2008 | doi = 10.1016/j.jaad.2007.07.011 | PMID = 18158926 }}</ref>
*[[Squamous cell carcinoma of the head and neck]].
*Others - see ''[[Dermatopathology#Leukoplakia]]''.


==Erythroplakia==
==Erythroplakia==
===General===
===General===
*Non-specific clinical finding - may be benign or malignant.
*Non-specific clinical finding - may be benign or [[malignant]].
*Strong association with non-keratinizing squamous lesions (invasive and dysplastic).
*Strong association with non-keratinizing squamous lesions (invasive and dysplastic).


Line 94: Line 76:
===Cystic lesions - overview===
===Cystic lesions - overview===
Lateral cystic lesions:
Lateral cystic lesions:
*[[Brachial cleft cyst]].
*[[Branchial cleft cyst]].
*[[Cystic hygroma]].
*[[Cystic hygroma]].


Line 119: Line 101:
==Benign lymphoepithelial lesion==
==Benign lymphoepithelial lesion==
*[[AKA]] ''benign lymphoepithelial cyst''
*[[AKA]] ''benign lymphoepithelial cyst''
 
{{Main|Benign lymphoepithelial lesion}}
===General===
*Usually parotid gland.
*Associated with autoimmune disease, e.g. [[Sjoegren disease]], may not remain benign.<ref name=pmid12058269>{{Cite journal  | last1 = Goto | first1 = TK. | last2 = Shimizu | first2 = M. | last3 = Kobayashi | first3 = I. | last4 = Chikui | first4 = T. | last5 = Kanda | first5 = S. | last6 = Toshitani | first6 = K. | last7 = Shiratsuchi | first7 = Y. | last8 = Yoshida | first8 = K. | title = Lymphoepithelial lesion of the parotid gland. | journal = Dentomaxillofac Radiol | volume = 31 | issue = 3 | pages = 198-203 | month = May | year = 2002 | doi = 10.1038/sj/dmfr/4600690 | PMID = 12058269 }}</ref>
 
===Microscopic===
Features:
*Lymphocytes.
*Ductal epithelial cells.<ref name=pmid12761623>{{Cite journal  | last1 = Metwaly | first1 = H. | last2 = Cheng | first2 = J. | last3 = Ida-Yonemochi | first3 = H. | last4 = Ohshiro | first4 = K. | last5 = Jen | first5 = KY. | last6 = Liu | first6 = AR. | last7 = Saku | first7 = T. | title = Vascular endothelial cell participation in formation of lymphoepithelial lesions (epi-myoepithelial islands) in lymphoepithelial sialadenitis (benign lymphoepithelial lesion). | journal = Virchows Arch | volume = 443 | issue = 1 | pages = 17-27 | month = Jul | year = 2003 | doi = 10.1007/s00428-003-0824-0 | PMID = 12761623 }}</ref>
 
Note:
*'''Must''' rule-out (MALT) [[MALT lymphoma|lymphoma]].
 
===IHC===
*CD20, CD3 -- mixed population.
*Kappa ~ lambda.


=Other benign=
=Other benign=
Line 151: Line 118:
*[[AKA]] ''pemphigus''.
*[[AKA]] ''pemphigus''.
**Should not be confused with ''[[bullous pemphigoid]]'' (which is less serious).
**Should not be confused with ''[[bullous pemphigoid]]'' (which is less serious).
===General===
*May lead to blindness.
*Oral lesion is classically: ''first to show & last to go''.
**Oral lesions usually precede the skin lesions.
Etiology:
*Autoimmune disease.
**Antibodies against: desmoglein 1, desmoglein 3.
===Microscopic===
Features:<ref>{{Ref PBoD8|1193}}</ref>
*Suprabasilar blistering.
DDx: [[Hailey-Hailey disease]].


==Pyogenic granuloma==
==Pyogenic granuloma==
Line 204: Line 156:


Work-up of negative H&E Bx differs by site:
Work-up of negative H&E Bx differs by site:
*Sunnybrook:<ref>S. Raphael. December 2008.</ref>
*One large hospital:
**[[LMWK]] ([[CAM5.2]]).  
**LMWK (CAM5.2).  
**[[pankeratin]] ([[AE1/AE3]]).
**Pankeratin ([[AE1/AE3]]).
*UHN.
*Another large hospital:
**Nothing.
**Nothing.


Line 252: Line 204:
==Granular cell tumour==
==Granular cell tumour==
{{Main|Granular cell tumour}}
{{Main|Granular cell tumour}}
===General===
*May mimic (well-differentiated) squamous cell carcinoma - histopathologically.
**There is a well-described phenomenon called ''[[pseudoepitheliomatous hyperplasia]]''.<ref name=pmid16487362>{{cite journal |author=Abu-Eid R, Landini G |title=Morphometrical differences between pseudo-epitheliomatous hyperplasia in granular cell tumours and squamous cell carcinomas |journal=Histopathology |volume=48 |issue=4 |pages=407–16 |year=2006 |month=March |pmid=16487362 |doi=10.1111/j.1365-2559.2006.02350.x |url=}}</ref>
*Usually a benign tumour.
===Microscopic===
Features:
*Large polygonal cells with abundant (eosinophilic) granular cytoplasm.
Image:
*[http://commons.wikimedia.org/wiki/File:Granular_cell_tumor_%283%29_skin.jpg Granular cell tumour (WC)].


==Olfactory neuroblastoma==
==Olfactory neuroblastoma==
:See also: ''[[neuroblastoma]]''.
:See also: ''[[neuroblastoma]]''.
*[[AKA]] ''esthesioneuroblastoma''.
*[[AKA]] ''esthesioneuroblastoma''.
===General===
{{Main|Olfactory neuroblastoma}}
Epidemiology:<ref name=pmid20596981/>
*Prognosis: poor.
*Wide age range with bimodal distribution - teens and 60s.
*No sex predilection.
 
Clinical presentation:<ref name=pmid20596981>{{Cite journal  | last1 = Thompson | first1 = LD. | title = Olfactory neuroblastoma. | journal = Head Neck Pathol | volume = 3 | issue = 3 | pages = 252-9 | month = Sep | year = 2009 | doi = 10.1007/s12105-009-0125-2 | PMID = 20596981 | PMC = 2811627 | URL = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2811627/?tool=pubmed }}</ref>
*Nasal obstruction ~ 70%.
*Epistaxis ~ 50%.
*Anosmia.
*Headache.
 
===Gross===
*Arises from olfactory mucosa - upper nasal cavity.<ref name=Ref_WMSP41>{{Ref WMSP|41}}</ref>
 
===Microscopic===
Features:<ref name=pmid20596981/>
*[[Small round cell tumour|Small round (blue) cell tumour]] with:
**Stippled chromatin.
**High NC ratio.
*+/-Flexner-Wintersteiner [[rosette]] - rosette with empty centre (donut hole).
*+/-Fibrillary, eosinophilic material (neuropil-like).<ref name=Ref_WMSP41>{{Ref WMSP|41}}</ref>
 
DDx:
*[[Lymphoma]].
*[[Small cell carcinoma]].
*Other [[small round cell tumours]].
*Basaloid squamous carcinoma.{{fact}}
 
Images:
*[http://path.upmc.edu/cases/case467/images/fig02.jpg Olfactory neuroblastoma - crappy image (upmc.edu)].<ref>URL: [http://path.upmc.edu/cases/case467.html http://path.upmc.edu/cases/case467.html]. Accessed on: 21 January 2012.</ref>
*[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2811627/figure/Fig6/ Olfactory neuroblastoma (nih.gov)].<ref name=pmid20596981/>
 
===IHC===
*S100:
**Sustentacular cells +ve.
**Small round cells -ve.
*Neuroendocrine markers +ve (CD56, synaptophysin).
 
Others:
*CD45 -ve (r/o [[lymphoma]]).
*AE1/AE3 usu. -ve (r/o carcinoma).
*CAM5.2 usu. -ve -- up to 35% +ve.<ref name=Ref_WMSP41>{{Ref WMSP|41}}</ref>


==Craniopharyngioma==
==Craniopharyngioma==
Line 319: Line 218:
:See also: ''[[Angiofibroma]]''.
:See also: ''[[Angiofibroma]]''.
*[[AKA]] ''juvenile nasopharyngeal angiofibroma''.
*[[AKA]] ''juvenile nasopharyngeal angiofibroma''.
===General===
{{Main|Nasopharyngeal angiofibroma}}
*Classically adolescent males with recurrent nose bleeds.


===Microscopic===
==Biphenotypic sinonasal sarcoma==
Features:<ref name=Ref_Klatt144>{{Ref Klatt|144}}</ref>
*[[AKA]] ''low grade sinonasal sarcoma with neural and myogenic features''.
*Fibroblastic cells with plump (near cuboidal) nuclei.
{{Main|Biphenotypic sinonasal sarcoma}}
*Fibrous stroma.
*Abundant capillaries.
 
Images:
*[http://commons.wikimedia.org/wiki/File:Nasopharyngeal_angiofibroma_-_intermed_mag.jpg Nasopharyngeal angiofibroma - intermed. mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Nasopharyngeal_angiofibroma_-_2_-_high_mag.jpg Nasopharyngeal angiofibroma - high mag. (WC)].


=Nasal polyps=
=Nasal polyps=
==Overview==
{{Main|Nasal polyps}}
DDx (benign - multiple):<ref name=emedicine994274>URL: [http://emedicine.medscape.com/article/994274-overview http://emedicine.medscape.com/article/994274-overview]. Accessed on: 16 March 2011.</ref>
*Autoimmune/idiopathic:
**Asthma.
**Allergic rhinitis.
**[[Churg-Strauss syndrome]] (AKA ''allergic granulomatous angiitis'').
***Features: [[asthma]], eosinophilia, granulomatous inflammation, necrotizing systemic [[vasculitis]], and necrotizing glomerulonephritis.<ref name=emedicine333492>[http://emedicine.medscape.com/article/333492-overview http://emedicine.medscape.com/article/333492-overview]</ref>
**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 carcinoma]]s.
**[[Sarcoma]]s.
**[[Hemangioma]].
**[[Schneiderian papilloma]].
**Other.
 
Memory devices:
*''GAIT'' = '''G'''enetic, '''A'''llergic/idiopathic, '''I'''nfectious, '''T'''umours.
*Allergic causes '''A'''s - '''a'''llergic, '''a'''sthma, '''a'''llergic granulomatous angiitis (Churg-Strauss syndrome), non'''a'''llergic rhinitis with eosinophilia.
 
===Epidemiology===
*More commonly assoc. with nonallergic conditions.<ref name=emedicine994274/>
 
===Treatment===
*Recurrent polyps: functional endoscopic sinus surgery (FESS).
 
==Inflammatory polyps with neutrophils==
===General===
*Histologic findings are non-specific; DDx includes:<ref name=emedicine994274dx>URL: [http://emedicine.medscape.com/article/994274-diagnosis http://emedicine.medscape.com/article/994274-diagnosis]. Accessed on: 16 March 2011.</ref>
**[[Cystic fibrosis]].
**Primary ciliary dyskinesia syndrome.
**Young syndrome
 
===Microscopic===
Features:
*Neutrophil predominant.
*Edema.
*+/-Mucus-impaction (dilated glands with mucus).
**Suggestive of cystic fibrosis.<ref name=pmid15554502>{{cite journal |author=Beju D, Meek WD, Kramer JC |title=The ultrastructure of the nasal polyps in patients with and without cystic fibrosis |journal=J. Submicrosc. Cytol. Pathol. |volume=36 |issue=2 |pages=155–65 |year=2004 |month=April |pmid=15554502 |doi= |url=}}</ref>
 
===Sign out===
<pre>
A. Nasal sinus tissue, right, excision:
- Inflamed edematous sinonasal mucosa with abundant neutrophils.
- Negative for malignancy.
 
B. Nasal sinus tissue, left, excision:
- Inflamed edematous sinonasal mucosa with abundant neutrophils and fragments of bone.
- Negative for malignancy.
</pre>
 
==Allergic nasal polyp==
===General===
*People with allergies.
**Same type of polyps seen in those without allergies.<ref name=pmid8441521>{{Cite journal  | last1 = Davidsson | first1 = A. | last2 = Hellquist | first2 = HB. | title = The so-called 'allergic' nasal polyp. | journal = ORL J Otorhinolaryngol Relat Spec | volume = 55 | issue = 1 | pages = 30-5 | month =  | year = 1993 | doi =  | PMID = 8441521 }}</ref>
 
===Gross===
*Polypoid mass - several millimetres to centimetres in size.
**Translucent.{{fact}}
 
===Microscopic===
Features:<ref>{{Ref Klatt|144}}</ref>
*Normal respiratory epithelium.
*Stroma with:
**Edema.
**Eosinophils.
**+/-Other inflammatory cells (plasma cells, lymphocytes, neutrophils).
 
DDx:
*Inflammatory nasal polyp with abundant neutrophils.
*[[Vasculitis]].
**[[Wegener's granulomatosis]].
**[[Churg-Strauss syndrome]].
 
===Sign out===
<pre>
A. Nasal sinus tissue, right, excision:
- Inflamed edematous sinonasal mucosa with abundant eosinophils.
- Negative for malignancy.
 
B. Nasal sinus tissue, left, excision:
- Inflamed edematous sinonasal mucosa with abundant eosinophils and fragments of bone.
- Negative for malignancy.
</pre>
 
 
<pre>
A. NASAL SINUS TISSUE, RIGHT, EXCISION:
- INFLAMED EDEMATOUS SINONASAL MUCOSA WITH ABUNDANT EOSINOPHILS.
- NEGATIVE FOR MALIGNANCY.
 
B. NASAL SINUS TISSUE, LEFT, EXCISION:
- INFLAMED EDEMATOUS SINONASAL MUCOSA WITH ABUNDANT EOSINOPHILS AND FRAGMENTS OF BONE.
- NEGATIVE FOR MALIGNANCY.
</pre>
 
==Tonsillar lymphangiomatous polyp==
===Microscopic===
Features:<ref>http://www.nature.com/modpathol/journal/v13/n10/full/3880208a.html</ref>
*Polyp with lymph channels.
 
==Schneiderian papilloma==
*[[AKA]] ''Schneiderian polyp''.
*[[AKA]] ''sinonasal papilloma''.<ref>URL: [http://emedicine.medscape.com/article/862677-overview http://emedicine.medscape.com/article/862677-overview]. Accessed on: 19 November 2011.</ref>
===General===
*Lumpers vs. splitters debate about whether it is one entity or three.<ref name=pmid11904343>{{cite journal |author=Barnes L |title=Schneiderian papillomas and nonsalivary glandular neoplasms of the head and neck |journal=Mod. Pathol. |volume=15 |issue=3 |pages=279–97 |year=2002 |month=March |pmid=11904343 |doi=10.1038/modpathol.3880524 |url=http://www.nature.com/modpathol/journal/v15/n3/full/3880524a.html}}</ref>
 
[http://www.nature.com/modpathol/journal/v15/n3/fig_tab/3880524t1.html#figure-title Subclassification]:<ref name=pmid11904343/>
*Inverted (Schneiderian) - most common ~60-65%.
*Fungiform (Schneiderian) - less common ~30-35%.
*Oncocytic (Schneiderian) - least common ~5%.
====Inverted====
*[[AKA]] ''[[inverted papilloma]]''.<ref name=pmid8189990>{{Cite journal  | last1 = Vrabec | first1 = DP. | title = The inverted Schneiderian papilloma: a 25-year study. | journal = Laryngoscope | volume = 104 | issue = 5 Pt 1 | pages = 582-605 | month = May | year = 1994 | doi =  | PMID = 8189990 }}</ref>
*Usually lateral wall (as the septum as little soft tissue to grow into).<ref name=pmid11904343/>
*May transform to carcinoma.
 
====Fungiform====
*[[AKA]] exophytic papilloma, [[AKA]] septal papilloma.<ref name=pmid11904343/>
*Low risk of malignant transformation.
 
====Oncocytic====
*[[AKA]] ''cylindrical cell papilloma''.<ref>{{Cite journal  | last1 = Bravo Domínguez | first1 = O. | last2 = Vela Cortina | first2 = M. | last3 = Ramírez Ruiz | first3 = RD. | last4 = Ros Vergara | first4 = A. | last5 = Dinarés Jaumeandreu | first5 = D. | last6 = Encina Ruiz | first6 = L. | last7 = Arias Cuchí | first7 = G. | last8 = Ardíaca Bosch | first8 = MC. | last9 = Cánovas Robles | first9 = E. | title = [Oncocytic schneiderian papilloma. A case report]. | journal = An Otorrinolaringol Ibero Am | volume = 32 | issue = 2 | pages = 115-23 | month =  | year = 2005 | doi =  | PMID = 15929584 }}</ref>
*Lateral nasal wall.<ref name=pmid11904343/>
 
===Microscopic===
====Inverted Schneiderian papilloma====
Features:<ref name=pmid11904343/>
*Well-demarcated epithelial islands in the stroma.
*Squamous +/-surface keratinization ''or'' respiratory type epithelium (with cilia).
*+/-Neutrophils.
*+/-Goblet cells.
 
Notes:
*May mimic invasive SCC.
 
Images:
*[http://path.upmc.edu/cases/case32.html Inverted papilloma & verrucous carcinoma (upmc.edu)].
*[http://commons.wikimedia.org/wiki/File:Sinonasal_papilloma_-_very_low_mag.jpg Schneiderian papilloma - very low mag. (WC)].
*[http://commons.wikimedia.org/wiki/File:Sinonasal_papilloma_-_cropped_-_very_high_mag.jpg Schneiderian papilloma - very high mag. (WC)].
 
====Fungiform Schneiderian papilloma====
Features:
*Exophytic growth pattern - '''key feature'''.
 
====Oncocytic Schneiderian papilloma====
Features:
*Oncocytes - '''key feature'''.
*Exophytic or endophytic growth pattern.


=See also=
=See also=
48,474

edits

Navigation menu