Dermoscopy of Mucosal Angiokeratomas: Diagnostic Pitfalls

Dear Editor,

Multiple angiokeratomas involving skin and mucosae are a feature of Fabry’s disease, which is a lipid storage disorder associated with deficiency of the enzyme alpha galactosidase A.[1] This genodermatosis, described in 1898 by Johannes Fabry and William Anderson, is characterized by an early childhood onset of extensive angiokeratomas, lenticular and corneal opacities, acroparaesthesia with acute exacerbation secondary to fever or stress, hypohidrosis, and gastrointestinal disturbances.[1] These lesions result from capillary obstruction, small nerve fiber damage, and autonomic neuropathy. The dermoscopic diagnosis of cutaneous angiokeratoma is well described,[2] facilitating early intervention. However, dermoscopic features of mucosal angiokeratomas have been sparsely described.[3,4] We describe the dermoscopic features of angiokeratomas on the labial mucosa in a young male with Fabry’s disease, highlighting diagnostic pitfalls to be avoided in this location.

A 17-year-old male presented with multiple, red-to-dark-blue, raised lesions predominantly involving the trunk. He reported recurrent episodes of fever associated with shooting acral pain, recurrent abdominal pain, and decreased sweating. On examination, numerous pink to dark-red to bluish, discrete, as well as grouped papules were identified over the trunk [Figures 1a and 1b]. The lesions were of variable size, and few were keratotic. Multiple, hyperpigmented, maculopapular, but shiny lesions were present on the dorsal aspect of anterior two-thirds of the tongue, with few discrete lesions present over the lateral edges as well [Figure 2]. Erythematous papules were present on the labial mucosa as well as on the hard palate and buccal mucosa. All lesions were mobile, firm, and did not bleed on manipulation [Figure 2].

Figure 1.

(a and b): Multiple dark-red and bluish, discrete, as well as grouped papules present over the trunk and genitalia

Figure 2.

Multiple, hyperpigmented shiny maculopapular lesions on the dorsal aspect of anterior two-thirds of the tongue, with few discrete lesions present over the lateral edges. Erythematous maculopapular lesions also present over the everted labial mucosa

Dermoscopic examination of the cutaneous lesions revealed well-demarcated reddish-blue lacunae with a whitish veil seen in multiple lesions [Figure 3]. Mucoscopy revealed multiple red lacunae, along with milky-red areas visualized on the labial mucosa [Figure 4]. However, lesions on the tongue showed hyperchromic, brown projections with pigmented borders and dichotomized vessels originating at their base. This was reminiscent of a “rose-petal pattern,” which is not suggestive of angiokeratomas but of pigmented fungiform papillae of the tongue.[5]

Figure 3.

Dermoscopy of cutaneous lesions revealed well-demarcated red and blue lacunae (yellow stars) with a whitish veil (white arrowheads) and keratotic surface in multiple lesions (Polarized 10×)

Figure 4.

Mucoscopy revealed multiple red lacunae over the labial mucosa (lower half of image) (yellow stars). The lesions on the tongue (upper half of the image) show hyperchromic, brown projections with pigmented borders suggestive of “rose-petal” appearance (red arrows). Dichotomized vessels seen in the papillae, originating near the base (black arrowheads) (Polarized 10×)

A skin biopsy and histopathology revealed the presence of hyperkeratosis, acanthosis, and proliferation of dilated blood vessels encroaching into the upper dermis. The findings were consistent with angiokeratoma. However, the patient did not agree for mucosal biopsy. Enzyme evaluation could not be done due to resource constraints. Based on the clinical, dermoscopic, and histopathological findings, a diagnosis of angiokeratoma corporis diffusum with Fabry’s disease with pigmented fungiform papillae of tongue (PFPT) was made.

Angiokeratomas are benign vascular lesions arising in the papillary dermis,[1,2] characterized by vascular ectasia with overlying epidermal hyperkeratosis. Clinically, the lesions present as aggregates of hyperkeratotic, erythematous, to violaceous papules, which may later become verrucous. Depending on their location and distribution, there are five clinical forms described; however, multiple lesions are a characteristic cutaneous marker of Fabry’s disease. They can be seen in 66% of male and 36% of female patients and appear between 5 and 13 years of age.[1] Lesions involve the lower limbs, trunk, tongue, scrotum, penile shaft, or labia majora.

To the best of our knowledge, mucoscopy of oral angiokeratomas has been sparsely described before.[3,4] Eskiizmir et al. described dermoscopic features of tongue angiokeratomas as sharply demarcated reddish-blue lacunae (corresponding to dilated and congested vessels), with whitish veil (corresponding to epidermal hyperkeratosis) along with milky-red areas.[4] Our case showed typical dermoscopic features for the cutaneous lesions; however, the labial mucosal lesions showed only red lacunae, with minimal to absent whitish veil. This could be because of the non-keratinizing stratified squamous epithelium lining the oral cavity.[4] Interestingly, the lesions over the tongue revealed a distinctive “rose-petal pattern” characterized by brown projections with pigmented borders and dichotomized vessels originating at the base. These features were suggestive of PFPT, as detailed by Robles-Méndez et al.[5] This is a benign condition, more commonly seen in children and young adults with darker skin phototypes.[5] Histopathology shows an increased basal layer pigmentation, melanophages in the lamina propria and dilated capillaries within the fungiform papillae.[5] Although the diagnosis of PFPT is clinical, dermoscopic evaluation reveals distinctive features. A knowledge of these mucoscopic findings is important to avoid confusion with mucoscopic features of other conditions presenting in this location including angiokeratomas.

To conclude, mucoscopy aids in non-invasive diagnosis of oral angiokeratomas, helping to differentiate it from confounding lesions such as PFPT, which is an incidental finding. These distinctive findings can help establish an early diagnosis and aid in early intervention.

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Patient consent was obtained for photography and publication of images, ensuring anonymity.

Author contributions

Both authors have equally contributed to the design of the manuscript and writing of the manuscript and are accountable for all aspects of the work along with ensuring accuracy or integrity of the manuscript.

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Nil.

Conflicts of interest

There are no conflicts of interest.