Acta Dermato-Venereologica 97-10CompleteContent | Seite 30

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SHORT COMMUNICATION
Coincident Metastatic Melanoma and Merkel Cell Carcinoma with Complete Remission on Treatment
with Pembrolizumab
Alexander THIEM 1,2 , Hermann KNEITZ 1 , Patrick SCHUMMER 1 , Stefan HERZ 3 , David SCHRAMA 1 , Roland HOUBEN 1 , Matthias
GOEBELER 1 , Bastian SCHILLING 1 and Anja GESIERICH 1
Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, DE-97080 Würzburg,
Comprehensive Cancer Center Mainfranken, and 3 Department of Diagnostic and Interventional Radiology, University Hospital Würzburg,
Würzburg, Germany. E-mail: [e-mail]
1
2
Accepted Jul 31, 2017; Epub ahead of print Aug 1, 2017
Patients with metastatic melanoma or Merkel cell carci-
noma (MCC) share a poor prognosis (1, 2). In recent years,
immune checkpoint inhibitors have significantly advanced
the treatment of immunogenic tumours (3).
The anti-programmed cell death protein 1
(PD-1) antibodies pembrolizumab and nivo-
lumab have been approved for the treatment
of advanced melanoma. Clinical trials have
provided evidence that pembrolizumab (4)
as well as the anti-programmed death-ligand
1 (PD-L1) antibody avelumab (5) are ef-
fective in the treatment of advanced MCC,
with avelumab approved by the US Food
and Drug Administration. We report here
on a patient presenting with both metasta-
tic melanoma and MCC who experienced
complete remission of both on treatment
with pembrolizumab.
endocrine primary. However, a suspicious pancreatic lesion (Fig.
1J) was biopsied and a melanoma metastasis diagnosed based on
morphology and IHC (MART-1- and HMB45-positive; nuclear
CASE REPORT
In July 2012, a 70-year-old man was diagnosed
with a metastatic melanoma. A swelling of the
right axilla was removed by surgery. Based on
morphology and immunohistochemistry (IHC),
an amelanotic lymph node metastasis, 5 cm in
diameter, with occult primary was diagnosed (Fig.
1 A–C). Level I/II lymph node dissection (0/23
nodes positive) was conducted, and he received
adjuvant radiotherapy of 50 Gy. Computed tomo-
graphy (CT) scans performed initially showed no
additional metastases. Follow-up was carried out
in accordance with national guidelines. In April
2016 CT revealed newly enlarged right inguinal
and iliac lymph nodes.
A systematic lymphadenectomy was conducted.
To our surprise, initial pathological review of the
dissected tissue detected infiltrates of neuroen-
docrine carcinoma in 7 of 20 inguinal and 8 of
20 iliac lymph nodes (Fig. 1D). IHC revealed
“dot-like” positivity for pan-cytokeratin (AE1/3)
and CK20, while TTF1, MITF, MART1 and
HMB45 were negative (Fig. 1E). Finally, diag-
nosis of MCC was made and further sustained by
strong positive immunolabelling for Merkel cell
polyomavirus (MCPyV) Large T antigen (clone
CM2B4; Fig. 1F). No primary MCC was recor-
ded in the patient’s medical history or found on
clinical examination. Endoscopy of the upper and
lower intestine did not reveal an internal neuro-
doi: 10.2340/00015555-2757
Acta Derm Venereol 2017; 97: 1252–1254
Fig. 1. (Immuno-)histological and radiological findings. (A–C) Amelanotic lymph node
melanoma metastasis from the right axilla. (A) Haematoxylin and eosin (H&E) staining
with atypical melanocytes positive for (B) MART-1 and (C) S100. (D–F) Iliac MCC lymph
node metastasis with round oval tumor cells containing (D) sparse cytoplasm and granular
chromatin on H&E staining with (E) „dot-like“-positivity for CK20 and (F) expression of Merkel
cell polyomavirus Large T antigen (MCPyV LT, stained with antibody clone CM2B4). (G-I) Both
the axillary lymph node metastasis (G) as well as the iliac MCC metastasis (H) are negative
for PD-L1 (immunolabelled with antibody clone E1L3N, tonsillar tissue served as positive
control for PD-L1 (I)). Magnification H&E 200x (A, D), all others 400x). (J–L) CT scans
demonstrating pancreatic melanoma metastasis (J) as well as an parailiac MCC metastasis
before (K) and after 7 applications of pembrolizumab (L). Arrow heads indicate metastases.
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Journal Compilation © 2017 Acta Dermato-Venereologica.