BCC

From dermoscopedia

Introduction[edit]

Basal cell carcinoma (BCC) is the most common type of skin cancer in the world. Although mortality related to BCC is negligible, BCCs can be associated with significant morbidity, especially if left untreated and/or if discovered when they have attained relatively large diameters. Clinically, BCC can present with a variety of morphologies ranging from erythematous patches to ulcerated nodules. There are multiple histopathologic subtypes of BCC including superficial, nodular, morpheaform/sclerosing/infiltrative, fibroepithelioma of Pinkus, microcytic adnexal and baso-squamous cell BCC. Each subtype can be pigmented or non-pigmented [1].

Dermoscopic features[edit]

Both the negative and the positive dermoscopic features associated with pigmented BCCs have been well characterized [2][3][4]. The negative feature of pigmented BCCs is that they cannot display any structures seen in melanocytic lesions including pigment network, streaks, negative network, aggregated or peripheral brown globules. The positive features of pigmented BCC include the presence of any one of the following structures:

2step4.jpg

Classical criteria[edit]

Arborizing vessels[edit]

These consist of multiple branching blood vessels in a tree-like pattern. The base of the vessel is larger and the branches of the vessel become smaller in diameter. The vessels tend to be bright red and sharply in focus. Arborizing vessels surround dermal basal cell tumor islands and thus are associated with nodular BCC.

BCC (polarized dermoscopy) displaying multiple arborizing vessels..
Superficial fine teleangiectasia[edit]

Superficial fine teleangiectasia are defined as short, fine, focused linear vessels with very few branches and they usually characterize superficial BCC[5].

Blue gray ovoid nests[edit]

The nests are defined as confluent or nearly confluent, well-circumscribed, pigmented ovoid areas. The difference between an ovoid nest and a blue-gray globule is the relative size of the structure. An ovoid nest encompasses at least 10% of the surface area of the lesion and blue-gray globules are smaller. The presence of an ovoid nest corresponds to basal cell tumor islands in the dermis and these lesions will prove to be nodular BCC on histopathology.

Blue gray ovoid nests and globules BCC schematic.jpg
Pigmented BCC (polarized light dermoscopy) displaying a large blue-gray ovoid nest, multiple non-aggregated blue-gray dots and globules, shiny white strands and an arborizing vessel.
Blue gray dots/ globules[edit]

Blue-gray dots are pinpoint blue-gray structures that are often distributed in a buckshot scatter like pattern (Figure ). This structure can be seen in early nodular BCC or in superficial BCC. Blue-gray globules are well-defined round or oval structures, larger than dots, but smaller than large ovoid nests. They are not aggregated as would be seen in melanocytic lesions. They usually have a blue-gray color; however, depending on the location within the dermis (Tyndall effect) and degree of melanin within the pigmented basaloid tumor islands, the globules can appear brown or pink in color. This structure corresponds to small basal cell tumor islands in the dermis and thus they will prove to be nodular BCC on histopathology.

Blue-gray globules &dots.jpg
Maple leaf like areas[edit]

These areas are defined as discrete, linear to bulbous extensions connected at an off-center base area, forming a leaf-like pattern. They are usually brown or gray-blue in color and they are quite specific for superficial BCC. The bulbous to linear extensions forming the leaf can sometimes be mistaken for the streaks seen in melanoma. However, the streaks in melanoma tend to be discrete, well-delineated, narrow, relatively in-focus linear extensions that are located at the border of the lesion and are directly connected to the main pigmented tumor mass. Streaks in melanoma always radiate in a direction pointing away from the main pigmented tumor mass and they radiate toward normal skin. In addition, streaks in a melanoma appear to converge towards the geometric center of the lesion, which is often hyperpigmented and has a blue-white veil. In contrast, extensions seen in leaf-like structures in BCC tend to be broader and often appear “fuzzy” or out of focus. They do not have to be located at the lesion’s border and they do not always have to radiate away from the main tumor mass toward normal skin. In addition, the extensions seen in BCC tend to converge at an off center pigmented base. This base, together with its “extensions”, is present focally and most often located towards the periphery of the tumor and it is this configuration that creates the leaf-like structure. In addition, the geometric center of BCCs manifesting “fuzzy streaks” (leaf-like areas) is often hypopigmented and relatively structureless.

Pigmented superficial BCC with multiple light brown leaf like areas.
Spoke wheel like structures/ concentric structures[edit]

These are radial projections that surround a central darker point. This is similar to leaf-like structures described above but instead of having the radial projections converging at an off-center base they radiate around a central base. The projections have a tan, blue, or gray color, and the central point or hub is usually dark brown, blue, or black. At times, the radial projections are not well defined and the spoke-wheel-like structure appears as a brownish round ill marginated globule that has a central darker hub; this particular patterned structure is called the ‘’’concentric structure’’’ or ‘’’concentric globule’’’. (Figure ). The spoke-wheel-like structure (including the concentric structure) is highly specific for superficial BCCs.

BCC Pigmented Multiple Abdomen Derm 2.JPG
Ulceration[edit]

These structures consist of shallow erosions that may be covered with congealed blood. They can also appear to have an orange hue if covered with a serous crust. Ulcers covering at least 10% of the surface area of the BCC correspond with nodular BCC. The presence of multiple smaller ulcers, termed erosions, is a feature seen in superficial BCC.

BCC with central ulcer surrounded by multiple arborizing and serpentine vessels.
Multiple small erosions[edit]

Multiple small erosions are usually seen as small brown–red to brown–yellow crusts and have usually been described in superficial BCC [5].

Shiny white/red structureless areas[edit]

Shiny white/red structureless areas may represent diffuse dermal fibrosis or fibrotic tumoral stroma and they have been described in superficial BCC[5].

Short white streaks (chrysalis)[edit]

Short white streaks (chrysalis) can be seen only with polarized dermoscopy as orthogonal short and thick crossing lines[5].

Superficial BCC (polarized dermoscopy) with shiny white blotches and strands. Both arborizing and serpentine vessels are also present.
Multiple aggregated yellow-white (MAY) globules[edit]

Some BCCs display multiple aggregated yellow-white (MAY) globules, typified by multiple, aggregated, white-to-yellowish globules arranged in clusters. MAY globules were seen in 21.0% nonpigmented BCCs, frequency similar to other BCC-specific criteria [6],[4]. Unlike milia-like cysts that are typically visible under nonpolarized light, MAY globules can be seen both in polarized and nonpolarized light [7].

BCC (polarized dermoscopy) displaying MAY globules.

Additional criteria[edit]

Superficial Basal Cell Carcinoma[edit]

The basaloid tumor islands in superficial basal cell carcinoma (sBCC) extend from the epidermis into the papillary dermis [8][9][10]. Dermoscopy can predict the diagnosis of sBCC with a sensitivity of 81.9% and specificity of 81.8% [11]. The features predictive of superficial BCC with odds ratios ranging between 2.7 and 7.7 include [12][13][11][14][15][16][17][18][19][20][21]:

  1. Leaf-like structures
  2. Spoke wheel-like structures
  3. Concentric structures/globules (variant of spoke wheel like structures)
  4. Brown dots – correspond to small pigmented BCC tumor islands located at the dermal-epidermal junction. Similar size pigmented BCC tumor islands in the papillary dermis appear as blue-gray dots/globules.
  5. Short fine superficial telangiectasia
  6. Multiple small erosions
  7. Shiny white blotches and strands. It is not uncommon for sBCC to only reveal shiny white blotches and strands with or without short fine superficial telangiectasia.

Features predictive against the diagnosis of sBCC include [11]:

  1. Arborizing vessels (negative odds ratio 2.1)
  2. Blue-gray ovoid nest/s (negative odds ratio 3.2)
  3. Ulceration (negative odds ratio 2.1)

Features that may be seen in sBCC but that are not predictive for or against the diagnosis of sBCC include multiple non-aggregated blue-gray globules and multiple in-focus blue-gray dots, which often present in a buckshot scatter distribution [11]. Heavily pigmented sBCC can sometimes mimic melanoma [4]. In such lesions the leaf-like or spoke wheel-like structures can resemble streaks (i.e., radial streaming and pseudopods) and the blue-gray globules can take on brown to black colors making it virtually impossible to differentiate these sBCC from melanoma [4][22]

Nodular Basal Cell Carcinoma[edit]

Nodular basal cell carcinoma (nBCC) is the most common sub-type and accounts for approximately 50-80% of BCCs. Clinically is manifests as an elevated tumor (papule or nodule) with a pearly and translucent margin and telangiectasia [23]. Some features are more common in nodular BCC compared to other BCC sub-types [11][24][16]. These include:

  • Arborizing vessels
  • Blue-gray ovoid nests
  • Ulceration

Features that are less likely to be seen in nodular BCC compared to other BCC subtypes include:

  • Leaf-like structures
  • Spoke wheel-like structures
  • Multiple small erosions
Infundibulocystic basal cell carcinoma[edit]

They are usually found on the head and neck of the elderly and clinically present as well-circumscribed pearly papules [25]. Dermoscopically, maple leaf-like areas at the periphery of the tumor, blue-gray dots and globules, short, fine telangiectasia and chrysalis have been described [26]

Morpheaform/ sclerosing/ desmoplastic basal cell carcinoma[edit]

It is clinically typified by an infiltrated plaque with poorly defined borders and shiny surface [25]. Dermoscopy showed structureless hypopigmentation (porcelain white areas), arborizing vessels, ulceration and, rarely, pigmentation was present (average of 0-13% of lesions), most commonly large blue-grey ovoid nests [27].

Fibroepithelioma of Pinkus[edit]

is an uncommon, indolent BCC subtype and can be described as skin-colored/ erythematous sessile plaque or pedunculated papulonodule with a predilection for the trunk [25]. Dermoscopy revealed red to light brown–yellow lesions, associated with irregularly shaped, linearly distributed, in focus telangiectasias, white septal lines (white streaks) in 90% of lesions and sometimes partial pigmentation characterized by an irregularly distributed, structureless gray-brown area of pigmentation associated with gray-blue dots, dotted vessels (70%), milia-like cysts (60%), and ulceration (50%) [28].

Basosquamous/ metatypical basal cell carcinoma[edit]

is a primarily histopathologic term as it refers to neoplasms that exhibit histologic features of both BCC and SCC [25]. Dermoscopy showed unfocused (peripheral) arborizing vessels (72.7%), keratin masses (72.7%), white structureless areas (72.7%), superficial scale (68.2%), ulceration or blood crusts (68.2%), white structures (63.6%), blue-grey blotches (59.1%), and blood spots in keratin masses (54.6%) [29].

False negative diagnosis[edit]

Of the 3 main skin cancers, BCC is less frequently mimicking a benign tumor. This is because the dermoscopic characteristics of BCC are quite peculiar and are rarely confused with structures suggestive of benign tumors.[30] Therefore, most BCCs are dermoscopically evident from a very early stage. Exceptions, however, do exist:

Non-pigmented BCC. Main false negative diagnosis: Dermal nevus The dermoscopic hallmark of BCC is its vascular pattern, which consists of the so-called “arborizing” vessels. These are ideally stem vessels of large caliber, projecting sharply in focus, branching in thinner vessels and finally terminal capillaries and typically cross the centre of the tumor.[30] However, deviations of this “ideal” pattern are frequent. Occasionally, the branches might be not very evident and the vessels might project as multiple short linear curved structures, somehow mimicking the so-called “comma vessels” of dermal nevi. Often, this is just an optical illusion caused by pressure applied during dermoscopic examination. Thus, dermoscopic examination of nodular lesions should be either non-contact (polarized) or at least with the use of an immersion fluid or gel to minimize the applied pressure.

Pigmented BCC. Main false negative diagnosis: Blue nevus As compared to non-pigmented BCC, pigmented variants are even easier to recognize, based on the unique morphology of BCC-specific pigmented structures (leaf-like structures, spoke-wheel, areas, concentric structures, blue dots/globules/nests).[30] However, when the pigmented basaloid nests are very large and heavily pigmented, they might result in diffuse blue pigmentation, which could mimic the pattern of blue nevi.[4] To address this problem, it has been suggested that the diagnosis of a blue nevus should always be confirmed by the history of a long-standing stable lesion.

Basal cell carcinoma with a homogeneous blue color and mimicking a blue nevus

False positive diagnosis[edit]

Clonal SK. Main false positive diagnosis: BCC, melanoma This peculiar SK variant dermoscopically displays globular structures of brown or blue-gray color, which might be misinterpreted as irregular globules of a melanoma or blue-gray ovoid nests of a basal cell carcinoma (4-6). The sharp demarcation of the lesion at the periphery or the co-existence of SK-specific structures (ex. milia-like cysts) might help to recognize SK.

This is a clonal linear epidermal nevus / seborrheic keratosis
Clonal seborrheic keratosis that could be mistaken for a BCC
This clonal seborrheic keratosis has features overlapping with melanoma and basal cell carcinoma

Angiokeratoma. Main false positive diagnosis: Melanoma, BCC Dark lacunae, red lacunae and whitish veil are the most frequent dermoscopic criteria of angiokeratomas. Dark lacunae represent the most useful feature, having a sensitivity of 93.8% and a specificity of 99.1% for the diagnosis of angiokeratoma when compared with several other benign and malignant tumors.

Angiokeratoma can sometimes mimic a melanoma or basal cell carcinoma

Follicular tumors. Main false positive diagnosis: BCC In general, the dermoscopic pattern of follicular tumours displays features overlapping with BCC, namely linear branching vessels and blue-grey dots or globules. The common presence of ‘white structures’ has been suggested as a dermoscopic clue, suggestive of the diagnosis of a follicular tumour. Specific dermoscopic criteria have are associated with some tumours, such as the unique ivory-white background colour that typifies desmoplastic trichoepithelioma.

Sebaceous tumors. Main false positive diagnosis: BCC Sebaceous hyperplasia is dermoscopically typified by a whitish umbilicated, polylobular or structureless centre, surrounded by elongated, scarcely branching vessels (crown vessels). A similar pattern consisting of central whitish/yellowish structures and crown vessels characterizes sebaceous cysts. The remaining sebaceous tumors are much more difficult to recognize. A possible clue is the combination of yellowish structures with unfocused arborising vessels.

Sweat gland tumors. Main false positive diagnosis: BCC, melanoma, SCC Eccrine poroma is the most well-studied sweat gland tumor and has been suggested to display a great dermoscopic variability, potentially mimicking all known malignant tumors.

Dermatopathological correlation[edit]

Arborizing vessels correspond to dilated vessels in the dermis and are the dermoscopic hallmark of nodular BCC.

Superficial fine teleangiectasia correlate with telangiectatic vessels located in the papillary dermis and they usually characterize superficial BCC.

Blue-gray ovoid nests correspond to large, well-defined tumor nests with pigment aggregates invading the dermis and they can be found in all BCC subtypes except of superficial BCC.

Blue-gray dots and globules are small, roundish tumor nests with central pigmentation, localized in the papillary and/or reticular dermis. They can be seen in all BCC subtypes.

Maple leaf-like areas correlate to multifocal tumor nests containing pigment aggregates which are interconnected by lobular extensions. They are generally localized in the epidermis and less frequently in the papillary dermis. They can be seen in all subtypes, but more frequently in superficial BCC.

Spoke wheel areas correspond to tumor nests arising and connected to the epidermis and are characterized by finger-like projections from a centrally located pigmentation. They can be seen in all subtypes, but more frequently in superficial BCC. Concentric structures, considered variations, or ‘precursors’ of the spoke wheel areas, can also be seen in all subtypes, but more frequently in superficial BCC.

Ulceration corresponds to loss of the epidermis, usually covered by hematogenous crusts. And typically characterizes nodular tumors.

Multiple small erosions correspond to thin crusts overlying a superficial loss of the epidermis. They are usually associated with superficial BCC and non-pigmented BCC[31].

Shiny white/red structureless areas may represent diffuse dermal fibrosis or fibrotic tumoral stroma and they have been described in superficial BCC.

Short white streaks (chrysalis) may be attributed to the presence of collagenous stroma and fibrosis in the dermis[5].

Multiple aggregated yellow-white (MAY) globules correlate with round, isolated areas of dystrophic calcification situated either within or near tumour nodules and with calcified keratocysts [32].

This chapter is based on the previous basal cell carcinoma chapter which can be found here: https://dermoscopedia.org/Basal_cell_carcinoma

Podcasts, Videos[edit]









References[edit]

  1. Lallas et al.: Dermoscopy uncovers clinically undetectable pigmentation in basal cell carcinoma. Br. J. Dermatol. 2014;170:192-5. PMID: 24117444. DOI.
  2. Menzies: Dermoscopy of pigmented basal cell carcinoma. Clin. Dermatol. 2002;20:268-9. PMID: 12074864.
  3. Menzies et al.: Surface microscopy of pigmented basal cell carcinoma. Arch Dermatol 2000;136:1012-6. PMID: 10926737.
  4. 4.04.14.24.34.4 Altamura et al.: Dermatoscopy of basal cell carcinoma: morphologic variability of global and local features and accuracy of diagnosis. J. Am. Acad. Dermatol. 2010;62:67-75. PMID: 19828209. DOI.
  5. 5.05.15.25.35.4 Lallas et al.: Dermoscopy in the diagnosis and management of basal cell carcinoma. Future Oncol 2015;11:2975-84. PMID: 26450622. DOI.
  6. Crotty & Menzies: Dermoscopy and its role in diagnosing melanocytic lesions: a guide for pathologists. Pathology 2004;36:470-7. PMID: 15370118. DOI.
  7. Jaimes et al.: White globules correlate with balloon cell nevi nests. J. Am. Acad. Dermatol. 2011;65:e119-e120. PMID: 21920229. DOI.
  8. Tabanlıoğlu Onan et al.: Correlation between the dermatoscopic and histopathological features of pigmented basal cell carcinoma. J Eur Acad Dermatol Venereol 2010;24:1317-25. PMID: 20337825. DOI.
  9. Stephens et al.: Spoke wheel-like structures in superficial basal cell carcinoma: a correlation between dermoscopy, histopathology, and reflective confocal microscopy. J. Am. Acad. Dermatol. 2013;69:e219-21. PMID: 24124839. DOI.
  10. Hirofuji et al.: Superficial type of multiple Basal cell carcinomas: detailed comparative study of its dermoscopic and histopathological findings. J Skin Cancer 2011;2011:385465. PMID: 21151508. DOI.
  11. 11.011.111.211.311.4 Lallas et al.: Accuracy of dermoscopic criteria for discriminating superficial from other subtypes of basal cell carcinoma. J. Am. Acad. Dermatol. 2014;70:303-11. PMID: 24268311. DOI.
  12. Khokhar: Growling, flushing, and a 30-pound weight loss. Hosp. Pract. (Off. Ed.) 1985;20:64-5. PMID: 2411744.
  13. Suppa et al.: Dermoscopic variability of basal cell carcinoma according to clinical type and anatomic location. J Eur Acad Dermatol Venereol 2015;29:1732-41. PMID: 25627865. DOI.
  14. Emiroglu et al.: The relation between dermoscopy and histopathology of basal cell carcinoma. An Bras Dermatol 2015;90:351-6. PMID: 26131865. DOI.
  15. Giacomel & Zalaudek: Dermoscopy of superficial basal cell carcinoma. Dermatol Surg 2005;31:1710-3. PMID: 16336893.
  16. 16.016.1 Popadić: Dermoscopic features in different morphologic types of basal cell carcinoma. Dermatol Surg 2014;40:725-32. PMID: 25111343. DOI.
  17. Trigoni et al.: Dermoscopic features in the diagnosis of different types of basal cell carcinoma: a prospective analysis. Hippokratia 2012;16:29-34. PMID: 23930054.
  18. Pan et al.: Dermatoscopy aids in the diagnosis of the solitary red scaly patch or plaque-features distinguishing superficial basal cell carcinoma, intraepidermal carcinoma, and psoriasis. J. Am. Acad. Dermatol. 2008;59:268-74. PMID: 18550207. DOI.
  19. Ahnlide et al.: Preoperative prediction of histopathological outcome in basal cell carcinoma: flat surface and multiple small erosions predict superficial basal cell carcinoma in lighter skin types. Br. J. Dermatol. 2016;175:751-61. PMID: 26921200. DOI.
  20. Micantonio et al.: Vascular patterns in basal cell carcinoma. J Eur Acad Dermatol Venereol 2011;25:358-61. PMID: 20561131. DOI.
  21. Puig et al.: Dermoscopic criteria and basal cell carcinoma. G Ital Dermatol Venereol 2012;147:135-40. PMID: 22481576.
  22. Bakos et al.: Radial streaking: unusual dermoscopic pattern in pigmented superficial basal cell carcinoma. J Eur Acad Dermatol Venereol 2007;21:1263-5. PMID: 17894724. DOI.
  23. Chung: Basal cell carcinoma. Arch Plast Surg 2012;39:166-70. PMID: 22783519. DOI.
  24. Longo et al.: Classifying distinct basal cell carcinoma subtype by means of dermatoscopy and reflectance confocal microscopy. J. Am. Acad. Dermatol. 2014;71:716-724.e1. PMID: 24928707. DOI.
  25. 25.025.125.225.3 Cameron et al.: Basal cell carcinoma: Epidemiology; pathophysiology; clinical and histological subtypes; and disease associations. J Am Acad Dermatol 2019;80:303-317. PMID: 29782900. DOI.
  26. Roldán-Marín et al.: Infundibulocystic basal cell carcinoma: dermoscopic findings and histologic correlation. Dermatol Pract Concept 2014;4:51-4. PMID: 25126459. DOI.
  27. Reiter et al.: Dermoscopic features of basal cell carcinoma and its subtypes: A systematic review. J Am Acad Dermatol 2021;85:653-664. PMID: 31706938. DOI.
  28. Zalaudek et al.: Dermoscopy patterns of fibroepithelioma of pinkus. Arch Dermatol 2006;142:1318-22. PMID: 17043187. DOI.
  29. Giacomel et al.: Dermoscopy of basosquamous carcinoma. Br J Dermatol 2013;169:358-64. PMID: 23607676. DOI.
  30. 30.030.130.2 Lallas et al.: The dermatoscopic universe of basal cell carcinoma. Dermatol Pract Concept 2014;4:11-24. PMID: 25126452. DOI.
  31. Neagu et al.: Minimizing the dermatoscopic morphologic overlap between basal and squamous cell carcinoma: a retrospective analysis of initially misclassified tumours. J Eur Acad Dermatol Venereol 2020;34:1999-2003. PMID: 31955467. DOI.
  32. Navarrete-Dechent et al.: Association of Multiple Aggregated Yellow-White Globules With Nonpigmented Basal Cell Carcinoma. JAMA Dermatol 2020;156:882-890. PMID: 32459294. DOI.