Transcript Melanocytic Slide Club Case 201

Melanocytic Slide Club
Case 202
Dr Richard A. Carr
M73. Pigmented lesion L cheek
?melanoma. Nov 2009
Results (N=28)
• BENIGN
• MALIGNANT
– LMM
– SSMM
– Nodular
– Min. Dev.
– Spitzoid
– Unclass.
0
28
19
1
1
1
1
2
• Clark
–I
– II
– III
– IV
–V
0
3
10
5
1
Results (N=28)
• Breslow
– Median (range): 0.8 (0.3 to 1.7)
• Growth Phase:
• Regression:
• Mitoses:
R = 1; V = 21
Y = 0; N = 20
Absent = 8; Low = 11
Expert Comments
“Difficult definite LMM, ?deep dermal component”
“Melanoma arising in LM mitoses 2/mm²
“Favour LMM over unclassifiable”
“Pigment synthesising melanoma / animal type - cell type
similar to that described in pigmented epithelioid
melanocytoma.”
“Atypical proliferation of epithelioid cells in the epidermis
with similar cells in the dermis. “
Other Section (not circulated)
At 2 months: Wider local excision.
Sampled in 2 TS. No Tumour
At 6 Months: Revision of Scar (keloidal)
At 18 Months: Local Recurrences x 3
Dermal Pigmented Epithelioid Cell
Component (Dermal Nodule)
Ball and Gorlitz 1994 Jam Acad Dermatol: 73 cases
• Clinical: 6.2mm mean dia. with central 1-5mm dark brown
or black macule or papule of recent onset
• Ordinary acquired or congenital naevus
• Central focus or foci of large epithelioid melanocytes in
variably sized nodular aggregates
• Heavily pigmented
• Cytologically bland or atypical
• Occupying 5 to 80% of naevus
• Associated melanophages
• Often transition of surrounding naevus
• Differential Diagnosis: Melanoma, Combined naevus
Melanocytic naevus with phenotypic
heterogeneity (Atypical Dermal Nodule)
v’s Melanoma
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Symmetrical v’s asymmetrical
Size: often <6mm v’s often >1cm
Lateral borders: Sharply v’s poorly defined
Focus: present well demarcated v’s variable
Atypia: absent or mild v’s moderate to severe
Mitoses: Absent or minimal v’s frequent
Lymphcytic reaction: Uncommon v’s frequent
Learning Points
• Beware of the epithelioid / pigmented
clone in sun-damaged skin of the elderly!!
• Not all malignant lesions have a prominent
host inflammatory reaction
• Mitotic figures may be sparse!