| Abstract|| |
Background: Acquired fibrokeratoma (AFK) is an uncommon, sporadic, benign, acquired, slow-growing dermo-epidermal tumour. Aims and Objectives: The purpose of this study was to summarize the demographic, clinical characteristics and treatment outcomes of patients with AFK in a tertiary care centre in South India. Methods: We evaluated the records of 26 patients with AFK who were diagnosed and treated in our centre between January 2017 and December 2021. The retrospective data related to age, sex, occupation, consistency, duration of lesions, history of trauma, anatomical site, morphological appearance, histopathological type, treatment provided and recurrence were taken into account and analysed. Results: Of the 26 patients, there were 21 males and 5 females. Fingers (n = 23) were the most common site involved, followed by toes (n = 2) and palm (n = 1). A total of 18 patients had finger-like projected lesions and eight patients had dome-shaped lesions. In histopathology, Type I AFK type was observed in 16 cases and Type II in 10 cases. Conclusion: We believe that our study would contribute by providing the clinical, histopathology and treatment outcomes of this uncommon dermo-epidermal tumour. The frequency of this condition is often underestimated as it is misdiagnosed for many other dermatological conditions.
Keywords: Acquired digital fibrokeratoma, acquired fibrokeratoma, acral fibrokeratoma
|How to cite this article:|
Palaniappan V, Sadhasivamohan A, Sankarapandian J, Karthikeyan K. Acquired fibrokeratoma: A retrospective study in a tertiary centre in South India. Indian J Dermatol 2022;67:312
|How to cite this URL:|
Palaniappan V, Sadhasivamohan A, Sankarapandian J, Karthikeyan K. Acquired fibrokeratoma: A retrospective study in a tertiary centre in South India. Indian J Dermatol [serial online] 2022 [cited 2022 Sep 30];67:312. Available from: https://www.e-ijd.org/text.asp?2022/67/3/312/356729
| Introduction|| |
Acquired digital fibrokeratoma (ADFK) is a dermo-epidermal tumour initially described in 1968 by Bart et al. As it can also occur in extradigital sites, a more appropriate nomenclature would be 'acquired fibrokeratoma' (AFK) or 'acral fibrokeratoma'. This condition has been reported among patients of various ethnicities and racial backgrounds, as mentioned in German, Polish, French, Japanese and Indian literature. AFK is uncommon and there are only a few large case series of this condition in the literature.,,, Hence in this retrospective study, we aim to describe the demography, clinical features, histopathological features and treatment outcomes of 26 clinicopathologically confirmed cases of AFK.
| Methods|| |
A retrospective analysis of the record of patients who attended the dermatology outpatient department in a tertiary care hospital with a clinicopathologically confirmed diagnosis of AFK between January 2017 and December 2021 was included in this study. The retrospective data related to age, sex, occupation, consistency, duration of lesions, history of trauma, anatomical site, morphological appearance, histopathological type, treatment provided and recurrence were taken into account and analysed. The patient's records with demographic data, complete clinical history, examination findings and treatment outcomes were included. Out of 34 cases of AFK, eight were excluded due to inadequate demographic data, clinical information or inconclusive histopathology. A total of 26 clinicopathologically confirmed cases of AFK were included in this study. The lesions were clinically and histologically categorized based on the variants described by Kint et al. Approval from the SMVMCH Ethics committee has been obtained on 05.10.2021.
| Results|| |
In the past 5 years, we have encountered 26 clinicopathologically confirmed cases of AFK. There were 21 males and 5 females (M:F = 4.2:1). The mean age of the patients was 39.42 ± 9.34 years (range = 17–58 years). Occupation-wise, the majority of the patients (16) were involved in agricultural activities, and six patients were in the construction industry.
The average duration before seeking medical advice was 21.03 ± 13.3 months (range = 6–72). Three of our patients remembered prior trauma at the AFK site. The pain was experienced in four patients. Twenty-three lesions were firm in consistency, and three were soft-to-firm in nature. Fingers (n = 23) were the most common site involved, followed by toes (n = 2) and palm (n = 1) [Figure 1],[Figure 2],[Figure 3]. In fingers, lesions were observed more commonly in the dorsum (15/23), followed by the volar aspect (8/23). In fingers, 18/23 patients had lesions over the right hand, their dominant side.
|Figure 1: A solitary shiny dome-shaped papule with a surrounding collarette rim seen over the volar aspect of the left thumb|
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|Figure 2: A solitary skin-coloured comma-shaped raised finger-like lesion seen over the dorsal aspect of the right fourth finger|
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|Figure 3: (a) A solitary, skin-coloured, non-tender, firm, raised finger-like protruding lesion over the dorsal aspect of the right fourth toe; (b) A single comma-shaped skin-coloured finger-like projecting lesion seen over the dorsal aspect of the left foot|
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Finger-like projected lesions (18/26) were the most common presentation clinically followed by dome-shaped lesions (8/26). Giant fibrokeratoma (>1 cm) was observed in one of our cases [Figure 4]. In histopathology, Type I AFK type was observed in 16 cases and Type II in 10 cases. Complete tumour excision was performed in 16 patients, and shave excision and excision with electrocautery in five patients each [Figure 5]. The patients were followed up for a duration of 6 months after the treatment. Recurrence was noted in two of our patients who underwent shave excision.
|Figure 4: A solitary, well-defined, tender, firm, raised hyperpigmented finger-like lesion over the centre of the left palm with a surrounding rim at the base, measuring 10 × 7 × 18 mm|
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| Discussion|| |
AFK is an uncommon, sporadic, benign, acquired, slow-growing, fibrous tumour that commonly affects the fingers, especially in areas adjacent to interphalangeal joints.,,, It can also occur on palms, dorsum of hands, nail bed, periungual region, wrist, elbows, knees, toe, ankle, sole, calf, prepatellar area, lower lips and nose.,, AFK has a slight preponderance among males and occurs more commonly in middle-aged adults. In a case series, Baykal et al. reported that all their 13 cases of AFK occurred in men. The mean age of onset in our study is similar to previous reports.,
The pathophysiology of ADFK is unknown. It is presumed to occur after trauma or repetitive irritation though there is no concrete evidence for this hypothesis. Three of our patients remembered prior trauma at the AFK site. AFK is a consequence of the neoformation of dense collagen fibres by fibroblasts with more capillaries and coarser elastic fibres than the normal surrounding dermis. Suh et al. suggested that factor XIIIa positive dermal dendrocyte plays a significant role in collagen synthesis of AFK.
It usually presents as an asymptomatic, single, smooth, flesh-coloured, dome-shaped or finger-like papule or nodule of size <1 cm in diameter. It may be sessile or pedunculated, and occasionally hyperkeratotic or verruciform in nature., At the base of the lesion, a characteristic collarette of slightly raised skin is seen in AFK. Larger lesions of size >1 cm which often cause significant pain are known as giant acquired digital fibrokeratoma. Fibrokeratoma of the plantar region tends to have a larger diameter (≥3 cm) at the time of diagnosis.
AFK has been associated with Staphylococcal aureus infections which trigger fibroblast proliferation, oral cyclosporine use, hypoesthesia and hemiplegia. Lee et al. reported a case of pyogenic granuloma arising from AFK. Shiiya et al. reported a case of AFK arising from pityriasis amiantacea of the scalp. The rare clinical presentations reported include multibranched periungual fibrokeratoma and multiple plantar nodules. In nails, it more commonly arises from the proximal matrix or nail bed. The other nail changes include trachyonychia, longitudinal grooves, subungual hyperkeratosis and onycholysis. In nails, the Koenen tumour is differentiated from acquired periungual fibrokeratoma by multiple lesions, clove-shaped gross appearance, association with tuberous sclerosis and stellate-shaped fibroblasts with occasional giant cells on histopathology.
The differential diagnoses of AFK are broad and enlisted with differentiating clinical and histopathological features in [Table 1].,,,,,,, The diagnosis needs to be confirmed with an excisional biopsy. Histopathologically, AFKs are fibroepithelial tumours characterized by epidermal hyperkeratosis, and acanthosis with predominant thick, compact, vertically oriented collagen fibres in the dermis [Figure 6],[Figure 7],[Figure 8]. Based on clinical and histopathological features, Kint et al. reported three different variants of AFK. Type I variant is characterized by dome-shaped lesion with a hyperkeratotic epidermis, and densely packed, thick collagen bundles with fine elastic fibres. Type II is usually tall with hyperkeratotic epidermis with increased and regularly arranged fibroblasts than Type I with decreased elastic fibres. Type III is clinically characterized by flat to dome-shaped lesions with poor cellular structure and absent elastic fibres.
|Figure 6: (a) Histopathology of finger-like fibrokeratoma showing polypoidal lesion with the acanthotic epidermis and orthokeratotic hyperkeratosis. The subepidermal proliferation of dense collagen fibres which are vertically oriented. Dermal adnexal structures are absent [haematoxylin and eosin (H&E) stain, 10× magnification]; (b) Vertically arranged collagen bundles (H&E stain, 40× magnification)|
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|Figure 7: Histopathology of dome-shaped fibrokeratoma showing hyperplastic acanthotic epidermis over a dermal proliferation composed of dense collagen fibers oriented in a vertical direction (H and E stain, 10× magnification)|
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|Figure 8: (a) Masson-Trichrome stain shows increased collagen bundles (blue); (b) Von-Gieson stain shows increased collagen (red) (40× magnification)|
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The dermoscopic features of AFK vary among different cases due to diverse degree of vessel formations and collagen fibre accumulation [Figure 9]. Rubegni et al. reported a central homogenous pale-yellow core fringed by a hyperkeratotic white scaly collarette which reflects the epidermal acanthosis, hyperkeratosis and the presence of dense collagen fibres. A whitish-yellow area with dotted, globular vessels was seen more peripherally. Hayashi et al. reported clumps of homogenous red lacunae divided by a white meshwork-like septal wall. The AFK usually do not self-resolve and recurrence is rare once treated.
|Figure 9: (a) Dermoscopy of dome-shaped papule showing collarette scaly fringe surrounding a central homogenous yellow region (black arrow) and dotted vessels (red arrow); (b) Dermoscopy of finger-shaped lesion showing lacunae separated by white hyperkeratotic septi (yellow arrow) and a hyperkeratotic white basal fringe (blue arrow) (image taken with Dermlite D4 dermoscope, 10× magnification, polarized image)|
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The treatment of choice is complete surgical excision to the basal attachment of the tumour to prevent a recurrence., Shave excision should be considered in cases of early diagnosis. Two of our patients who underwent shave excision had a recurrence of the tumour. Conventional surgery with primary closure or with flaps is considered in larger lesions. Lesions beneath the nail need partial or total removal of the nail. Surgical excision under banner flap has been suggested for periungual lesions to lower the recurrence risk and for better cosmetic outcomes. The other alternate therapies for AFK include electrodesiccation, CO2 laser ablation and cryotherapy. A major limitation of this study is its retrospective nature and dermoscopy was performed only in four cases.
| Conclusion|| |
The frequency of this tumour is often underestimated as it is misdiagnosed for many other dermatological conditions. Also, many patients do not seek treatment for this relatively asymptomatic benign tumour. It is an easily manageable entity in which a simple excision is curative.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]