10.5826/dpc.1303a185
text/xml
2160-9381
2992
en
Jesus  Borbujo 
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
dermoscopy
Atypical Presentation of BAP-1 Inactivated Melanocytic Tumor
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2023-07-31
2022-11-22
2023-07-31
2023-08-24
e2023185
Dermatol Pract Concept
Jesus  Borbujo 
2023/07/31
10.5826/dpc.1303a185
e2023185
Department of Dermatology, Hospital Universitario de Fuenlabrada, Madrid, Spain
2160-9381
dermoscopy
en
e2023185
Zhang AJ, Rush PS, Tsao H, Duncan LM. BRCA1-associated protein (BAP1)-inactivated melanocytic tumors. J Cutan Pathol. 2019;46(12):965-972. DOI: 10.1111/cup.13530. PMID: 31233225.
Atypical Presentation of BAP-1 Inactivated Melanocytic Tumor
https://dpcj.org/index.php/dpc/article/download/2992/2231
        An Atypical Presentation of BAP1-Inactivated
                     Melanocytic Tumor
    Sara Pilar Herrero-Ruiz1, Helena Álvarez-Garrido1, Anastasia Alejandra Garrido-Ríos1,
               Laura Fernández de la Fuente1, Radia Khedaoui2, Jesus Borbujo1


1 Department of Dermatology, Hospital Universitario de Fuenlabrada, Madrid, Spain
2 Department of Pathology, Hospital Universitario de Fuenlabrada, Madrid, Spain



Key words: BAP1-inactivated melanocytic tumor, scalp, dermoscopy
Citation: Herrero-Ruiz SP, Álvarez-Garrido H, Garrido-Ríos AA, Fernández de la Fuente L, Khedaoui R, Borbujo J. An Atypical
Presentation of BAP1-Inactivated Melanocytic Tumor. Dermatol Pract Concept. 2023;13(3):e2023185.
DOI: https://doi.org/10.5826/dpc.1303a185
Accepted: February 8, 2023; Published: July 2023
Copyright: ©2023 Herrero-Ruiz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use,
distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing interests: None.
Authorship: All authors have contributed significantly to this publication.
Corresponding author: Sara Pilar Herrero-Ruiz (MD), 2 Molino Street, Fuenlabrada, Madrid, 28942 Spain. E-mail: sarahr-6@hotmail.com




Introduction                                                                  Physical examination showed a 2-cm pink pedunculated
                                                                         hyperkeratotic lesion located in the interparietal region, with
BAP1-inactivated melanocytic tumor (BIMT) is considered                  multiple surrounding smaller erythematous papules (Figure 1,
a type of intermediate melanocytic tumor [1]. Clinically                 A and D). Dermoscopy showed multiple telangiectasias and
BIMTs are described as a unique papule from 2 to 10 mm in                whitish scales on a pink background (Figure 1, B and C).
diameter. The size and number of BIMTs in our patient are                     The largest lesion was excised, and histopathology revealed
not consistent with these previous descriptions.                         that the dermis was expanded by a cellular substitution ar-
                                                                         ranged in nests and streams (Figure 2A). Some cells had a nevic
                                                                         appearance and were epithelioid in morphology (Figure 2B),
Case Presentation
                                                                         occasionally pigmented, and extended deep surrounding the
A 47-year-old woman presented with a lesion on the scalp                 adnexal structures, with no tendency to maturation. They
that had been stable since childhood, however during the                 presented well-defined limits, a wide eosinophilic cytoplasm,
last 6 months it had experienced a progressive enlargement.              prominent nucleoli and pseudoinclusions. It also showed a
The patient had family history of different malignancies.                focus with nests of a conventional nevus (Figure 2C).
Her mother and aunt had had non-melanoma skin cancer,                         Immunohistochemistry obtained a positive result for
father had had leukemia, several uncles had had lung and                 melan-A in the entire sample (Figure 2D). BAP1 expression
breast cancer, and her grandparents had had pancreatic and               was lost except in the conventional-appearing nevus compo-
lung cancer.                                                             nent (Figure 2E), so the final diagnosis was a BIMT.




Research Letter | Dermatol Pract Concept. 2023;13(3):e2023185                                                                          1
Figure 1. (A) Erythematous pedunculated papule with yellow and whitish scales on its surface and multiple small similar lesions on the base.
(B) Dermoscopy of the biggest lesion showed thick central telangiectasia with several thinner vessels in the rest of the lesion, on a pink back-
ground with whitish scales. (C) The smaller papules had similar dermoscopic findings, with short fine telangiectasias. (D) After the excision
of the largest tumor, hair in the area was shaved and up to 10 similar lesions of smaller size were observed.




    After these histopathological findings, all the smaller               melanocytes [1]. BAP1 is a tumor suppressor gene, and mu-
papules that surrounded the biggest lesion were extirpated                tations of this gene result in some human cancers. Germline
revealing the same histopathologic features. Because of the               mutations have been described in families with a hereditary
multiple lesions and the familiar history of malignancies, ge-            increased risk of certain cancers like cutaneous and uveal mel-
netic counseling was given for the BAP1 tumor predisposi-                 anoma, malignant mesothelioma, renal cell carcinoma and
tion syndrome with a negative result.                                     other internal malignancies like lung or breast cancer [2,4].
                                                                              Usually the proliferation index is low (<5%) so it is con-

Conclusions                                                               sidered a low-grade dysplasia BIMT and the recommenda-
                                                                          tion is to remove it completely with a 2 mm margin. If the
BIMT is considered a type of intermediate melanocytic tu-                 proliferation is higher, it is considered a high-grade dyspla-
mor, that has been recently described [1]. Clinically BIMTs               sia BIMT and the suggested resection margins are from 5 to
are described as a unique skin-colored to reddish-brown,                  10 mm [1]. Genetic counseling should be given according to
dome-shaped to pedunculated well-circumscribed papule,                    personal and familial history of malignancies and in cases of
from 2 to 10 mm in diameter [2]. Dermoscopically BIMTs                    multiples BIMTs [2,5].
are characterized by homogenous pink or milky red back-                       BIMTs are considered a type of intermediate melanocytic
ground with sparse linear or arborising vessels [3]. Most                 tumor, typically described as a single erythematous papule.
commonly occur in the second and third decades of life [4].               The presentation of multiple smaller-sized BIMTs surround-
    The diagnosis is best confirmed by BAP1 immu-                         ing a larger, more typical BIMT in the scalp is different to
nochemistry with loss of nuclear expression in the altered                previously described cases.




2                                                                             Research Letter | Dermatol Pract Concept. 2023;13(3):e2023185
Figure 2. Histopathological findings. (A) The dermis was expanded by a cellular substitution arranged in nests and cords. (H&E, x 2).
(B) Cells showed nevic appearance and epithelioid morphology (H&E, x 40). (C) It showed on the base a focus with nests of a conventional
nevus (H&E, x 20). (D) Positive result for melan-A in the entire sample (IHC melan-A, x 10). (E) BAP1 expression was lost except in the
conventional-appearing nevus component (IHC BAP1, x 2).


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Research Letter | Dermatol Pract Concept. 2023;13(3):e2023185                                                                           3
