Difference between revisions of "Melanocytic lesions"

Jump to navigation Jump to search

Melanocytic lesions (view source)

Revision as of 18:47, 11 February 2021

4,886 bytes removed ,  18:47, 11 February 2021
→‎Desmoplastic melanocytic nevus: +nodal nevus
 
(11 intermediate revisions by the same user not shown)
Line 1: Line 1:
[[Image:Blue nevus - intermed mag.jpg|thumb|right|A melanocytic lesion ([[blue nevus]]). [[H&E stain]]. (WC/Nephron)]]
'''Melanocytic lesions''' are commonly encountered in [[dermatopathology]] and an area which causes some difficulty, i.e. it is hard to decide in some cases whether a lesion is benign (e.g. [[Spitz nevus]]) or malignant ([[malignant melanoma]]).
'''Melanocytic lesions''' are commonly encountered in [[dermatopathology]] and an area which causes some difficulty, i.e. it is hard to decide in some cases whether a lesion is benign (e.g. [[Spitz nevus]]) or malignant ([[malignant melanoma]]).


Line 110: Line 111:
=Lentiginous melanocytic lesions=
=Lentiginous melanocytic lesions=
==Lentigo simplex==
==Lentigo simplex==
*[[AKA]] ''simple lentigo''.<ref>URL: [http://www.dermnetnz.org/lesions/lentigo-simplex.html http://www.dermnetnz.org/lesions/lentigo-simplex.html]. Accessed on: 27 March 2013.</ref>
{{Main|Lentigo simplex}}
===General===
*Benign.
*Usually <40 years old.
 
Fits into the larger category of ''lentiginous melanocytic proliferations'' - these include:<ref name=Ref_Derm438>{{Ref Derm|438}}</ref>
*[[Solar lentigo]].
*Lentigo simplex.
*[[Lentiginous nevus]].
*Lentiginous [[melanoma in situ]].
 
Associated syndromes:<ref name=dermamin_ls>URL: [http://dermaamin.com/site/histopathology-of-the-skin/64-l/1852-lentigo-simplex-.html http://dermaamin.com/site/histopathology-of-the-skin/64-l/1852-lentigo-simplex-.html]. Accessed on: 17 December 2012.</ref>
*[[Peutz-Jeghers syndrome]].
*[[LEOPARD syndrome]].
*[[LAMB syndrome]].
 
===Gross===
*Small flat pigmented lesion.<ref name=Ref_WMSP498>{{Ref WMSP|498}}</ref>
 
DDx - clinical:
*[[Melanocytic nevus]].<ref name=pmid19536147>{{Cite journal  | last1 = Hafner | first1 = C. | last2 = Stoehr | first2 = R. | last3 = van Oers | first3 = JM. | last4 = Zwarthoff | first4 = EC. | last5 = Hofstaedter | first5 = F. | last6 = Klein | first6 = C. | last7 = Landthaler | first7 = M. | last8 = Hartmann | first8 = A. | last9 = Vogt | first9 = T. | title = The absence of BRAF, FGFR3, and PIK3CA mutations differentiates lentigo simplex from melanocytic nevus and solar lentigo. | journal = J Invest Dermatol | volume = 129 | issue = 11 | pages = 2730-5 | month = Nov | year = 2009 | doi = 10.1038/jid.2009.146 | PMID = 19536147 }}</ref>
 
===Microscopic===
Features:<ref name=Ref_WMSP498>{{Ref WMSP|498}}</ref>
*Melanocytes in epidermis only.
**Melanocytes basally located (normal location) with hyperpigmentation.
*No melanocytic nests.
*+/-Mild/moderate elongation of the rete ridges.<ref name=pmid19536147/>
 
DDx:<ref name=humpath_ls/>
*[[Solar lentigo]] - solar elastosis, usu. in sun exposed areas.
*[[Ephelis]] (freckle) - change with UV light exposure.
*Melanotic macule.
*[[Lentiginous nevus]] - has melanocytic nests.
 
====Images====
*[http://dermaamin.com/site/histopathology-of-the-skin/64-l/1852-lentigo-simplex-.html Lentigo simplex - several images (dermamin.com)].<ref name=dermamin_ls/>
*[http://www.humpath.com/IMG/jpg/lentigo_simplex_20x.jpg Lentigo simplex (humpath.com)].<ref name=humpath_ls>URL: [http://www.humpath.com/?lentigo-simplex http://www.humpath.com/?lentigo-simplex]. Accessed on: 17 December 2012.</ref>
<gallery>
Image:Skin_Tumors-171.jpg | Simple lentigo. (WC)
</gallery>
 
===Sign out===
<pre>
SKIN LESION, LEFT ABDOMEN, BIOPSY:
- SIMPLE LENTIGO, COMPLETELY EXCISED IN THE PLANE OF SECTION.
</pre>
 
<pre>
SKIN LESION, LEFT ABDOMEN, BIOPSY:
- BENIGN SIMPLE LENTIGO.
</pre>
 
====Micro====
The sections show skin with increased numbers of small pigmented melanocytes at the dermal-epidermal junction. The rete ridges are mildly elongated. No solar damage is apparent. No dermal melanocytes are identified. No melanocytic nests are identified. No nuclear atypia is apparent.


==Solar lentigo==
==Solar lentigo==
Line 191: Line 138:
**Classically at the tips of the rete ridges.
**Classically at the tips of the rete ridges.
*No (melanocyte) nuclear atypia.
*No (melanocyte) nuclear atypia.
*Solar damage ([[solar elastosis]]).<ref name=pmid19536147/>
*Solar damage ([[solar elastosis]]).<ref name=pmid19536147>{{Cite journal  | last1 = Hafner | first1 = C. | last2 = Stoehr | first2 = R. | last3 = van Oers | first3 = JM. | last4 = Zwarthoff | first4 = EC. | last5 = Hofstaedter | first5 = F. | last6 = Klein | first6 = C. | last7 = Landthaler | first7 = M. | last8 = Hartmann | first8 = A. | last9 = Vogt | first9 = T. | title = The absence of BRAF, FGFR3, and PIK3CA mutations differentiates lentigo simplex from melanocytic nevus and solar lentigo. | journal = J Invest Dermatol | volume = 129 | issue = 11 | pages = 2730-5 | month = Nov | year = 2009 | doi = 10.1038/jid.2009.146 | PMID = 19536147 }}</ref>


Notes:
Notes:
Line 297: Line 244:
*[[AKA]] ''intradermal melanocytic nevus''.
*[[AKA]] ''intradermal melanocytic nevus''.
*[[AKA]] ''intradermal nevus'', abbreviated ''IDN''.<ref name=pmid11493376>{{Cite journal  | last1 = Fullen | first1 = DR. | last2 = Reed | first2 = JA. | last3 = Finnerty | first3 = B. | last4 = McNutt | first4 = NS. | title = S100A6 preferentially labels type C nevus cells and nevic corpuscles: additional support for Schwannian differentiation of intradermal nevi. | journal = J Cutan Pathol | volume = 28 | issue = 8 | pages = 393-9 | month = Sep | year = 2001 | doi =  | PMID = 11493376 }}</ref>
*[[AKA]] ''intradermal nevus'', abbreviated ''IDN''.<ref name=pmid11493376>{{Cite journal  | last1 = Fullen | first1 = DR. | last2 = Reed | first2 = JA. | last3 = Finnerty | first3 = B. | last4 = McNutt | first4 = NS. | title = S100A6 preferentially labels type C nevus cells and nevic corpuscles: additional support for Schwannian differentiation of intradermal nevi. | journal = J Cutan Pathol | volume = 28 | issue = 8 | pages = 393-9 | month = Sep | year = 2001 | doi =  | PMID = 11493376 }}</ref>
 
{{Main|Intradermal nevus}}
*Only in the dermis - '''key feature'''.
*+/-Adipocytes - uncommon.<ref name=pmid9810886>{{Cite journal  | last1 = Eng | first1 = W. | last2 = Cohen | first2 = PR. | title = Nevus with fat: clinical characteristics of 100 nevi containing mature adipose cells. | journal = J Am Acad Dermatol | volume = 39 | issue = 5 Pt 1 | pages = 704-11 | month = Nov | year = 1998 | doi =  | PMID = 9810886 }}</ref>
 
Note:
*In the oral cavity these are known as ''[[intramucosal melanocytic nevus|intramucosal nevi]]''.


===Sign out===
===Sign out===
Line 321: Line 263:


====Intradermal melanocytic nevus====
====Intradermal melanocytic nevus====
<pre>
{{Main|Intradermal nevus}}
SKIN LESION, BACK, PUNCH BIOPSY:
- BENIGN INTRADERMAL NEVUS.
</pre>
 
=====Adipocytes present=====
<pre>
SKIN LESION, BACK, PUNCH BIOPSY:
- BENIGN INTRADERMAL NEVUS WITH MATURE ADIPOCYTES.
</pre>
 
=====Clinically suspicious=====
<pre>
SKIN LESION, LEFT UPPER ARM, PUNCH BIOPSY:
- BENIGN INTRADERMAL NEVUS, INCOMPLETELY EXCISED.
 
COMMENT:
HMB-45 marks very rare superficial cells. Ki-67 staining does not show apparent melanocyte
staining. MITF marks the melanocytes and demonstrates maturation of the melanocytes with depth.
</pre>
 
=====Micro=====
The sections show melanocytes in the dermis separated from the epidermis by a Grenz zone.  The lesion is symmetrical in its architecture and pigment distribution.  Superficially, melanocytes are in nests.  Melanocytes mature with depth. No mitotic activity is appreciated.
 
The lesion is completely excised in the plane of section.


==Congenital-pattern nevus==
==Congenital-pattern nevus==
Line 433: Line 351:


==Acral nevus==
==Acral nevus==
*[[AKA]] ''melanocytic nevus with intraepidermal ascent of cells'' (MANIAC).
*[[AKA]] ''melanocytic nevus with intraepidermal ascent of cells'' ([[MANIAC]]).
*[[AKA]] ''volar nevus''.
*[[AKA]] ''volar nevus''.
===General===
{{Main|Acral nevus}}
*Palms ''or'' soles.
 
Note:
*''Volar'' refers to the palmar aspect ''or'' plantar aspect.<ref>URL: [http://www.medterms.com/script/main/art.asp?articlekey=9907 http://www.medterms.com/script/main/art.asp?articlekey=9907]. Accessed on: 14 January 2013.</ref>
 
===Gross===
*Pigmented lesion.
 
Note:
*Should be bisected perpendicular to the dermatoglyphs (ridges).<ref name=pmid22703907/>
**Lesions sectioned parallel to the ridges (on microscopy) may appear to have confluent junctional nests (leading to the diagnosis of melanoma).
===Microscopic===
Features:
*Acral skin:
**Thick stratum corneum (hyperkeratotic).
**Thick stratum spinosum (acanthotic).
*Nevus with intraepidermal ascent of cells.
**May be referred to as ''Pagetoid scatter''.
**Should '''not''' be present at the edge of the lesion - '''key feature'''.<ref name=pmid22703907/>
 
Notes:
*Intraepidermal ascent of cells is usually suggestive of melanoma.
**In acral sites (esp. at the centre of a lesion) the criteria are relaxed, i.e. this is considered benign for this site.
*Nests in the ridges raise the suspicion of melanoma.
**Memory device "ridges are risky, furrows are fine".<ref name=pmid22703907>{{Cite journal  | last1 = Elston | first1 = D. | title = Practical advice regarding problematic pigmented lesions. | journal = J Am Acad Dermatol | volume = 67 | issue = 1 | pages = 148-55 | month = Jul | year = 2012 | doi = 10.1016/j.jaad.2012.04.006 | PMID = 22703907 }}</ref>
 
DDx:
*Acral lentiginous [[melanoma]].


==Dysplastic melanocytic nevus==
==Dysplastic melanocytic nevus==
Line 502: Line 392:
**Should stain approximally the same number of cells as Melan A.
**Should stain approximally the same number of cells as Melan A.
*Ki-67 -- only rare cells.
*Ki-67 -- only rare cells.
==Nodal nevus==
*AKA ''nevus in lymph node'' and ''benign nevus cells in lymph node''.
{{Main|Nodal nevus}}


=Miscellaneous=
=Miscellaneous=
Line 629: Line 523:
*[[Cytopathology]].
*[[Cytopathology]].
*[[Non-malignant skin disease]].
*[[Non-malignant skin disease]].
*[[Pigmented lesions of the oral cavity]].
*[[Melanosis coli]].
*[[Small bowel pseudomelanosis]].


=References=
=References=
Michael
48,466

edits

Retrieved from "https://librepathology.org/wiki/Special:MobileDiff/28323...51106"

Navigation menu