Firm digital papulonodules in a young boy

Abstract

A 3-year-old boy presented with firm, non-tender papulonodules over the left middle finger. They were initially thought to be insect bites then became firm over 2 weeks then gradually increased in size over 6 months. On examination there was a 1.2 9 0.9 cm firm nodule on the radial aspect and another 0.5 9 0.5 cm firm papule on the ulnar aspect of the left middle finger middle phalanx ( Fig. 1). Radiographic examination showed soft tissue swelling without bony abnormalities. Biopsy of the lesion showed spindled cells containing round to ovoid cytoplasmic inclusion bodies, consistent with the diagnosis of infantile digital fibromatosis (Fig. 2). The lesions were excised with full-thickness skin grafting. However, 2 months postoperatively, a new fleshy nodule developed on the ulnar aspect of the left index finger over the distal interphalangeal joint ( Fig. 3). DiscussionInfantile digital fibromatosis (IDF) is a rare benign myofibrocytic tumor. A third of cases are present at birth, and the majority become clinically evident within the first year of life. However, there have been cases described in adolescents and adults.Although the exact etiology is unknown, trauma has been considered a triggering factor. IDF can present singly or as multiple smooth, round, indurated, pinkish papules localized to the lateral and dorsal aspects of digits, sparing the thumb and great toe. Most lesions are painless and non-pruritic. These lesions exhibit an indolent progression initially, followed by a rapid growth phase over the ensuing months that could result in functional impairment and contractures. Malignant transformation or metastasis has never been reported. 1 Diagnosis of IDF is essentially clinical, and the main differential diagnoses encompass the group of fibromatoses including pachydermodactyly, terminal osseous dysplasia and pigmentary defects, keloids, and juvenile aponeurotic fibroma. 2 Figure 1 1.2 9 0.9 cm firm nodule on the radial aspect and 0.5 9 0.5 cm firm papule on the ulnar aspect of the left middle finger middle phalanx ª

Firm Digital Papulonodules in an Infant

“…Although there is a recurrence rate of up to 50% after excision, most lesions eventually will spontaneously regress and will leave no scar. [8][9][10] The clinical and histopathologic differential diagnoses of IDF include other cutaneous diseases that occur in the digits. A dermatofibroma is a round, firm, fibrohistiocytic nodule that mainly occurs on the extensor limbs.…”