10.5826/dpc.1302a68
text/xml
2160-9381
2542
en
Simona Sola
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
basomelanocytic tumor
Amelanotic Basomelanocytic Tumor
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Research Letter
2023-04-29
2022-04-17
2023-04-29
2023-06-05
e2023068
Dermatol Pract Concept
Simona Sola
2023/04/29
10.5826/dpc.1302a68
e2023068
Surgical Pathology, E.O. "Ospedali Galliera" Genoa-Italy
2160-9381
basomelanocytic tumor
en
e2023068
Bostanci S, Akay BN, Kirmizi A, Okcu Heper A, Farabi B. Basosquamous carcinoma and melanoma collision tumor in a child with xeroderma pigmentosum. Pediatr Dermatol. 2020;37(2):390-392. DOI: 10.1111/pde.14097. PMID: 31957124.
Amelanotic Basomelanocytic Tumor
https://dpcj.org/index.php/dpc/article/download/2542/2093
                 Hypomelanotyc Basomelanocytic Tumor
                       Cesare Massone1, Sanja Javor1, Stefano Chiodi2, Simona Sola3


1 Dermatology Unit, E.O. “Ospedali Galliera”, Genoa, Italy
2 Plastic Surgery, E.O. “Ospedali Galliera”, Genoa, Italy
3 Surgical Pathology, E.O. “Ospedali Galliera”, Genoa, Italy



Key words: basal cell carcinoma, melanoma, collision tumor, basomelanocytic tumor
Citation: Massone C, Javor S, Chiodi S, Sola S. Hypomelanotyc Basomelanocytic Tumor. Dermatol Pract Concept. 2023;13(2):e2023068.
DOI: https://doi.org/10.5826/dpc.1302a68
Accepted: July 14, 2023; Published: April 2023
Copyright: ©2023 Massone 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: Cesare Massone, MD, Dermatology Unit - Ospedali Galliera. Via Volta 6, 16128, Genova (IT). Phone: 0039 010
5632 4271. E-mail: cesare.massone@galliera.it




Introduction                                                             red areas, atypical vessels, ulceration and crusts (Figure 1, A
                                                                         and B). She denied previous history of skin cancer.
Dermoscopic diagnosis of collision tumor (CT) is a challenge.                 Histopathological examination showed an irregular
Zaballos et al recently found that the most frequent CTs are:            hyperplastic epidermis and, in the dermis, BerEp4-positive
basal cell carcinoma (BCC)-seborrheic keratosis (37.9%),                 large nests (Figure 1F) composed by basaloid keratinocytes
BCC-melanocytic nevus (19.9%), and melanoma-seborrheic                   with palisading of cells at the periphery and clefts with the
keratosis (6.8%).1 The collision BCC-melanoma is very rare               surrounding stroma (Figure 1, C-E and I). Inside some nests
(reported under the terms “basomelanocytic tumor (BMT)”)                 and in the dermis was present a second cell population of
and its dermoscopic features have been described in only few             spindle cells and also dentritic cells that stained positive for
cases [1,3-6].                                                           Melan-A, S100 and HMB-45 (Figure 1, G and H). An in-
                                                                         creased number of single atypical melanocytes at the der-

Case Presentation                                                        moepidermal junction was also observed.
                                                                              A BMT (BCC and pT2b melanoma of 1mm Breslow
A 58-year-old woman presented with an enlarging ulcerated                thickness; BRAF WT) was diagnosed. Wide surgical excision
erythematous-brown plaque of 16 x 8 mm on her left leg ap-               and lymph node biopsy were performed with no evidence
peared almost six months before. The clinical diagnosis was              of metastatic cells, also at staging investigations (pT2b N0
ulcerated BCC. Dermoscopy showed an asymmetric poly-                     M0). After 24-months follow-up the patient is still without
chromatic multicomponent pattern with shiny white struc-                 evidence of secondary disease.
tures, structureless blue-grey areas, grayish peppering, milky




Research Letter | Dermatol Pract Concept. 2023;13(2):e2023068                                                                          1
Figure 1. (A) Erythematous violaceous plaque of 16 x 8 mm with erosive surface on the lower limb of atypical morphology and multicolor
appearance. (B) Asymmetric polychromatic multicomponent pattern with shiny white structures, structureless blue-gray areas, milky red
areas, atypical vessels, ulceration and crusts without clearly pigment network at the periphery. (C) Irregular hyperplastic epidermis and, in
the dermis, large nests composed by basaloid keratinocytes with palisading of cells at the periphery, clefts with the surrounding stroma and
inflammatory infiltrate of the perilesional area (H&E; original magnification 5x). (D) Irregular hyperplastic epidermis and, in the dermis,
large nests of basaloid cells with a second cell population of spindle cells and dentritic cells. Heavy inflammatory infiltrate of the perilesional
area (H&E; original magnification 5x). (E). Higher magnification of the basaloid cells, atypical spindle and dentritic cells with mitotic figures
(H&E; original magnification 20x). (F) Strong immunoreactivity for BerEp4 evidenced the basal cell carcinoma component (original magnifi-
cation 5x). (G) Melan-A stained the atypical melanocytes of the melanoma component. An increased number of single atypical melanocytes at
the dermoepidermal junction and in the dermis was also observed (original magnification 5x). (H) HMB-45 stained the atypical melanocytes
of the melanoma component. An increased number of single atypical melanocytes at the dermoepidermal junction and in the dermis was also
observed (original magnification 5x).(I) Large nest of basaloid cells with palisading at the periphery (original magnification 5x).




Conclusions                                                                tumors is usually recognized upon dermoscopy when one of
                                                                           the two component is prevalent, but usually the exact diag-
Histologically, BMT may result by a variety of modality of                 nosis of BMT is difficult. Reflectance confocal microscope
“collisions” like colonization, combined, biphasic, bipheno-               (RCM) can be highly useful in the diagnosis [4]. Moreover,
typic, or intermingled neoplasms [2].                                      BMT can occur in patient with basal cell nevus syndrome or
    Pathogenetic explanations are different and refer to:                  xeroderma pigmentosum, therefore an accurate examination
the field cancerization theory (proliferation of two distinct              of the patients is needed [6]. Our patient presented an ulcer-
clones resulting in the development of two intermingled neo-               ated hypomelanotic BMT, representing a further pitfall.
plasms); the tumor divergent theory (biphasic neoplasm with                     The biologic behavior of BMT is still not clearly un-
two neoplastic populations); tumor convergent theory (two                  derstood. According to Amin et al distant metastases are
phenotypically different cell populations derive from a com-               uncommon and combined cutaneous tumors may have a
mon progenitor stem cell). BMT has also been considered                    better prognosis when compared to similarly staged conven-
a low-grade malignancy with a dual phenotype; in fact, the                 tional melanomas [2]. In contrast, Erickson et al, reported
histologic merging between two malignant cell types argues                 a 56-year-old man with BMT of the scalp who developed a
against a simple collision [2,3].                                          subsequent metastasis [2].
    To our knowledge, about 50 cases of BMT have been                           In conclusion, BMT represent a clinical diagnostic chal-
reported in the literature [1,3-6]; dermoscopy has been de-                lenge and suspicious lesions should be observed accurately
scribed in details in only 9 cases (Table 1). One of the two               with dermoscopy and also with RCM, when available.




2                                                                               Research Letter | Dermatol Pract Concept. 2023;13(2):e2023068
      Table 1. Dermoscopic features of the basomelanocytic tumors reported in the literature [1,3-6].
                                      Clinical
  Age/sex          Location          diagnosis         Collision                               Dermoscopy
 70-year-old    face               lentigo          BCC – lentigo      Annular granular pattern with rhomboid structures and
 man                               maligna          maligna            a dark blotch; large blue-gray ovoid nests with leaf-like
                                   melanoma         melanoma           structures
 69-year-old    postauricular      BCC              metastatic         Multilobulated bluish nodule with a shiny surface, fine
 man            region                              melanoma           blood vessels and large gray-blue ovoid structures.
                                                    colliding with
                                                    BCC
 70-year-old    frontoparietal Lentigo              BCC- lentigo       A flat brownish asymmetric lesion with an irregular
 man            region         maligna              maligna            pigmented network, whitish areas, vessels with linear or
                                                                       arciform shapes and a well-defined, darker area showing
                                                                       four colors (blue, black, white ⁄ grey, red) and black, bluish
                                                                       rounded structures; scales and an erosive site, as well as
                                                                       numerous vessels with arboriform shape; projections of
                                                                       bulbous shape reminiscent of leaf-like structures.
 74-year-old    head/neck          BCC- lentigo     BCC- lentigo       Pink-white area with arborizing vessels and a pseudo
 man                               malignaa         maligna            network with asymmetrically pigmented follicular
                                                                       openings.
 na             na                 lentigo          BCC – lentigo      Pigmented follicles and destroyed follicle with patchy
                                   maligna          maligna            pigmentation; arborizing vessels and pigmented blue-
                                                                       grayish globules
 60-year-old    Frontal            Melanoma         BCC – lentigo      Multi-component pattern with multiple blue-gray spots,
 man            region                              maligna            hypochromic area, shiny white streaks and amorphous
                                                    melanoma           areas, in addition to an atypical vascular pattern
 60-year-old    Left lumbar        Melanoma         BCC –              Asymmetric lesion with multicomponent pattern, atypical
 man            region             and BCCa         melanoma in        pigment network irregular globules in the periphery,
                                                    situ               multiple colors, particularly a blue coloration in the center-
                                                                       right of the lesion
 13-year-old    right jawline      Melanoma         BCC –              Ulcerated lesion showed chaos of colors including pink,
 boy with a                                         nodular            white, black, gray, and blue structureless areas, gray
 history of                                         melanoma           dots, linear, looped, and serpentine vessels, ulceration,
 XP-C                                                                  hemorrhage, keratin, scale, and fiber sign
 48-year-old    Back               BCC?             BCC –              Pink structureless area in the center with short, fine
 man with                          Melanoma?        melanoma in        telangiectasias and an atypical network at the periphery
 with basal                                         situ
 cell nevus
 syndrome

BCC = Basal cell carcinoma; na = not available; XP = xeroderma pigmentosum.
a
 diagnosed with the aid of reflectance confocal microscopy.



References                                                              4. Moscarella E, Rabinovitz H, Oliviero MC, et al. The role of
                                                                           reflectance confocal microscopy as an aid in the diagnosis of
 1. Zaballos P, Álvarez Salafranca M, Medina C, et al. The Use-            collision tumors. Dermatology. 2013;227(2):109-117. DOI:
    fulness of Dermoscopy for the Recognition of Malignant Col-            10.1159/000351771. PMID: 24080548.
    lision Tumors. Dermatology. 2022;238(1):132-139. DOI:               5. Blum A, Siggs G, Marghoob AA, et al. Collision skin lesions-­
    10.1159/000514583. PMID: 33789291.                                     results of a multicenter study of the International D
                                                                                                                               ­ ermoscopy
 2. Cota C, Saggini A, Lora V, et al. Uncommon Histopathological           Society (IDS). Dermatol Pract Concept. 2017;7(4):51-62.
    Variants of Malignant Melanoma: Part 1. Am J Dermatopathol.            DOI: 10.5826/dpc.0704a12. PMID: 29230351. PMCID:
    2019;41(4):243-263. DOI: 10.1097/DAD.0000000000001218.                 PMC5720595.
    PMID: 30024414.                                                     6. Bostanci S, Akay BN, Kirmizi A, Okcu Heper A, Farabi B.
 3. Busam KJ, Halpern A, Marghoob AA. Malignant melanoma                   Basosquamous carcinoma and melanoma collision tumor
    metastatic to a basal cell carcinoma simulating the pattern of a       in a child with xeroderma pigmentosum. Pediatr Derma-
    basomelanocytic tumor. Am J Surg Pathol. 2006;30(1):133-136.           tol. 2020;37(2):390-392. DOI: 10.1111/pde.14097. PMID:
    DOI: 10.1097/01.pas.0000179118.76904.02. PMID: 16330954.               31957124.




Research Letter | Dermatol Pract Concept. 2023;13(2):e2023068                                                                           3
