Supernumerary digits are soft tissue growths that lack a skeletal component.1 They can appear as fleshy or verrucous-like papules, or present as larger, pedunculated nodules. Supernumerary digits are present at birth and often found bilaterally, with the most common location being the lateral aspect of the fifth finger.
Acral fibrokeratomas, also known as acquired digital fibrokeratomas, are relatively rare, benign skin growths.1,9 They present as skin-colored to pink, faintly keratotic papulonodules. Acral fibrokeratomas are typically solitary and tend to occur on the fingers and toes of middle-aged adults. They also can be seen on the palms and soles.9
Currently, there is no agreed-upon treatment approach for IDFs. Surgical excision is a viable option; however, recurrence is common with an estimated recurrence rate between 61% to 74%.3 Therefore, surgical excision is typically reserved for symptomatic cases causing pain or functional impairment.
Nonsurgical options include topical steroids, intralesional triamcinolone, or intralesional 5-fluorouracil (5-FU).3 However, these nonsurgical approaches have not been studied extensively, given the rarity of this condition. Eypper and colleagues recently proposed a management algorithm for IDFs: If symptomatic, proceed to surgical excision; if asymptomatic but greater than 1 cm, treat with intralesional triamcinolone or intralesional 5-FU; if asymptomatic and less than 1 cm, continue to monitor.
A shave biopsy confirmed the diagnosis of IDF in this infant girl. The growth continued to rapidly enlarge, causing slight distortion of the distal interphalangeal joint. Surgical excision was performed at the age of 14 months without complication. However, at age 3 years the patient returned to the clinic for evaluation of a new growth on the dorsolateral aspect of her distal left fourth finger, clinically consistent with IDF. There also was evidence of recurrence of the previously excised IDF on her left fifth finger.
Given the small size of these growths (both less than 1 cm), clinicians opted to closely monitor the patient and prescribed clobetasol 0.05% cream to be used 2 times daily on the affected areas.
1. Bolognia JL, Jorizzo JL, Schaffer JV, et al. Dermatology, 3rd ed. London: Elsevier Ltd; 2012:1009, 1144, 1964-1965, 1969-1970.
2. Heymann WR. Infantile digital fibromatosis. J Am Acad Dermatol. 2008;59(1):122-123.
3. Eypper EH, Lee JC, Tarasen AJ, Weinberg MH, Adetayo OA. An algorithmic approach to the management of infantile digital fibromatosis: review of literature and a case report. Eplasty. 2018;18:e19.
4. Plusjé LG, Bastiaens M, Chang A, Hogendoorn PC. Infantile-type digital fibromatosis tumour in an adult. Br J Dermatol. 2000;143(5):1107-1108.
5. Laskin WB, Miettinen M, Fetsch JF. Infantile digital fibroma/fibromatosis: a clinicopathologic and immunohistochemical study of 69 tumors from 57 patients with long-term follow-up. Am J Surg Pathol. 2009;33(1):1-13.
6. Niamba P, Léauté-Labrèze C, Boralevi F, et al. Further documentation of spontaneous regression of infantile digital fibromatosis. Pediatr Dermatol. 2007;24(3):280-284.
7. Marks E, Ewart M. Infantile digital fibroma: a rare fibromatosis. Arch Pathol Lab Med. 2016;140(10):1153-1156.
8. Ward PE, McCarthy DJ. Periungual fibroma. Cutis. 1990;46(2):118-124.
9. Boffeli TJ, Abben KW. Acral fibrokeratoma of the foot treated with excision and trap door flap closure: a case report. J Foot Ankle Surg. 2014;53(4):449-452.