Vertical Ex Vivo Dermoscopy in Assessment of Malignant Skin Lesions

Abstract

The role of vertical ex vivo dermoscopy relevant to clinical diagnosis has not been investigated yet. Study objectives were defining, describing, and determining the importance of the structures visible using vertical ex vivo dermoscopy in the diagnosis of malignant skin lesions, as well as determining their accuracy in the assessment of tumor margins. A prospective, descriptive study was conducted in two University centers. Digital images of completely excised skin lesions, fixed in formalin, before histopathological diagnosis were used for analysis. BCCs had the most diverse dermoscopic presentation on the vertical section, while SCCs showed a similar presentation in most cases. Vertical dermoscopy of thin melanomas was almost identical, unlike nodular melanomas. Thickness accuracy assessed by dermatologist was 0.753 for BCC, 0.810 for SCC, and 0.800 for melanomas, whereas assessment by pathologist was 0.654, 0.752, and 0.833, respectively. The accuracy of tumor width assessment was 0.819 for BCCs, 0.867 for SCCs and 1.000 for melanoma as estimated by a Dermatologist. Interobserver agreement was 0.71 for BCC, 0.799 for SCC and 0.832 for melanomas. Vertical ex vivo dermoscopy may contribute to the distinction between BCCs, SCCs, and melanomas. Moreover, regardless of the doctor's specialty, it enables a good assessment of the tumor's margins.

Keywords: dermoscopy; ex vivo; histopathology; malignant skin lesions; vertical view.

Figure 1

Basal cell carcinomas (a) superficial, (c) nodular, (e) adenoid-superficial, (g) nodulo-cystic. ex vivo dermoscopy and histopathology. Horizontal plane, insets: non-specific dermoscopic finding; (a) vertical plane: a clearly visible tumor bud invading the papillary dermis; (b) Histopathology HEx20: multifocal tumor nests of basaloid cells originating from the epidermis. (c) vertical plane: two whitish, deeper tumor islands confluent in the central part; (d) Histopathology HEx15: tumor islands start from the epidermis and invade the dermis. (e) vertical plane: translucent tumor tissue that reaches the hypodermis; (f) Histopathology HEx7, inset ×40: reticulated pseudoglandular structures of basaloid cells. (g) vertical plane: raised whitish tumor island, interspersed with hemorrhage in the central part; (h) Histopathology HEx20: BCC with hemorrhage in the intratumoral stroma.

Figure 2

Basal cell carcinomas (a) nodulo-adenoid, (c) superficial, ex vivo dermoscopy and histopathology. (a) horizontal plane, inset: on horizontal ex vivo dermoscopy, we clearly see blue-gray ovoid nests, a few arborizing blood vessels, as well as whitish areas and lines; (a) vertical plane: on a vertical section, we could see the exact size, shape, pigmentation, and configuration of the tumor islands; (b) Histopathology HEx7, inset ×100: solid tumor islands with pseudoglandular formationes in the dermis. (c) horizontal plane, inset: this aspect allows us to see multiple brown dots and numerous whitish areas; (c) vertical plane: a thin pigmented line could be seen on the surface of the tumor bud; (d) Histopathology HEx20: superficial BCC with slight pigmentation in multifocal tumor nests.

Figure 3

Basal cell carcinomas (a) nodular, (c) adenoid-cystic, (e) nodular, (g) nodular-adenoid, ex vivo dermoscopy and histopathology. (a) horizontal plane, inset: intense brown pigmentation dominates the findings; (a) vertical plane: homogeneously pigmented and whitish tumor island that invades the dermis; (b) Histopathology HEx20: focally eroded BCC nodules. (c) horizontal plane, inset: central dominance of whitish area with peripheral indigo blue pigmentation; (c) vertical plane: translucent whitish tumor island that invades the subcutaneous fat tissue; (d) Histopathology HEx7: reticulated pseudoglandular structures of basaloid cells with central cystic formation. (e) horizontal plane, inset: translucent, pale pigmented homogenous area as a dominant feature, with a few linear blood vessels; (e) vertical plane: a whitish, thick, linear-shaped tumor island that invades the dermis; (f) Histopathology HEx10: BCC nodules in superficial part of dermis. (g) horizontal plane, inset: non-specific dermoscopic finding with pronounced whitish areas. (g) vertical plane: homogenous, thick whitish tumor island, irregularly linear in shape that invades the dermis; (h) Histopathology HEx7: solid tumor islands with pseudoglandular formations.

Figure 4

Basal cell carcinomas (a) micronodular, (c,e) infiltrative, ex vivo dermoscopy and histopathology. Horizontal plane, insets: dominance of whitish areas. (a) vertical plane: clearly limited tumor tissue that invades the hypoderm; (b) Histopathology HEx10: Micronodular BCC, with small tumor nests (inset ×100) invading deeper central parts of the subcutaneous fat tissue. (c,e) vertical plane: (c) flattened and (e) raised whitish tumor island that invades the entire thickness of the dermis, with unclear boundaries; (d) Histopathology HEx10: Infiltrative BCC, with irregular tumor islands (inset ×100), reaching junction of the reticular dermis with the subcutaneous fat. (f) Histopathology HEx10: infiltrative BCC invading superficial parts of the subcutaneous fat tissue.

Figure 5

Morbus Bowen, ex vivo dermoscopy and histopathology. (a) horizontal plane: dominance of whitish keratin deposits; (b) vertical plane: whitish tumor tissue present within the epidermis with numerous polymorphic linear blood vessels; (c) Histopathology HEx20: widened epidermis, with full thickness atypia.

Figure 6

Invasive squamous cell carcinomas, ex vivo dermoscopy and histopathology. (a,c,e,g) horizontal plane, insets: eroded whitish and partially pigmented areas. (a,c,e,g) vertical plane: similar presentations in the form of thick, whitish tumor nodules with variable levels of penetration. (b) Histopathology HEx7: tumor tissue of well-differentiated carcinoma penetrates the reticular dermis into subcutaneous fat. (d,f) Histopathology HEx7: tumor tissue of well-differentiated carcinoma penetrates the reticular dermis. (h) Histopathology HEx10: moderately differentiated SCC (follicular/infundibular type).

Figure 7

Melanomas, ex vivo dermoscopy and histopathology. (a) in situ, horizontal plane: asymmetry of structures and colors; (b) vertical plane: thick, superficial pigmented line; (c) Histopathology: lentiginous melanoma with PRAME ×200-positive basal and scattered suprabasal melanocytes. (d) in situ, horizontal plane: striking radial lines partially present on the tumor periphery; (e) vertical plane: thick pigmented line, within the epidermis; (f) Histopathology HEx40: shows in situ melanoma and band-like lymphocytic infiltrate in superficial dermis with scattered melanophages. (g) superficial spreading melanoma, horizontal plane: characteristic brown pigmentation with whitish fields and vertical growth phase; (h) vertical plane: typical melanin color homogeneously present in tumor tissue; (i) Histopathology HEx10: showing prominent vertical growth phase and the peripheral radial growth phase.

Figure 8

Nodular melanomas, ex vivo dermoscopy and histopathology. Horizontal plane: (a) Breslow 3 mm, and (d) Breslow 4mm: chaos in colors and structure; (b) vertical plane: thick, pale pigmented tumor tissue, linear in shape with whitish central depigmentation; (c) Histopathology HEx7: nodular dermal proliferation of atypical melanocytes with ulceration and vascular invasion, without radial growth phase and pigmentation. (e) vertical plane: intense melanin pigmentation, non-pigmented islands, and pronounced fibrosis in the form of bright white areas; (f) Histopathology HEx7: nodular dermal proliferation of atypical melanocytes with ulceration, without vascular invasion and pigmentation.

Figure 9

Vertical ex vivo dermoscopy and histopathology, comparative view. (a,c,e) horizontal plane insets: nonspecific dermoscopic presentations (a) basal cell carcinoma, adenoid-cystic type: tumor tissue that invades dermis, without thickening of the epidermis; (b) Histopathology HEx15: reticulated pseudoglandular structures of basaloid cells with central cystic formation. (c) squamous cell carcinoma: tumor that rises with thickening of the epidermis and invasion of the dermis; (d) Histopathology HEx7: tumor tissue of well-differentiated carcinoma penetrates the reticular dermis. (e) superficial spreading melanoma, Breslow 6mm: a linear-shaped, heavily pigmented tumor that extends to the hypodermis; (f) Histopathology HEx7: asymmetric proliferation of atypical melanocytes, with ulceration, focal low-grade pigmentation and vascular invasion.

Figure 10

Accuracy of basal cell carcinomas thickness measured by (a) dermatologist, and (b) pathologist using vertical ex vivo dermoscopy [15,16], and (c) interobserver agreement (* Weighted Kappa).

Figure 11

Accuracy of squamous cell carcinomas thickness measured by (a) dermatologist, and (b) pathologist using vertical ex vivo dermoscopy [15,16], and (c) interobserver agreement (^# ICC—Intraclass Correlation Coefficient).

Figure 12

Accuracy of melanoma thickness measured by (a) dermatologist, and (b) pathologist using vertical ex vivo dermoscopy [15,16], and (c) interobserver agreement (^# ICC—Intraclass Correlation Coefficient).

Figure 13

Accuracy of width using vertical ex vivo dermoscopy measured by dermatologist in (a) basal cell carcinomas, (b) squamous cell carcinomas, and (c) melanomas [15,16].