Fibrous hamartoma of infancy associated to hyperhidrosis: A case report

Fibrous hamartoma of infancy (FHI) is a rare benign soft tissue tumor, and its association with local hyperhidrosis has only been reported anecdotally. A 1-year-old healthy girl presented with a mass localized in the sacrococcygeal region associated to hypertrichosis and skin discoloration, non-tender on palpation. Ultrasound (U/S) revealed a predominantly hypoechogenic 42 x 14 mm lesion with hyperechogenic tissue. A magnetic resonance imaging (MRI) revealed a 7.4 x 4.4 cm superficial soft tissue lesion with heterogeneous contrast enhancement involving the subcutaneous and cutaneous layers, extending to the underlying muscular fascia. The patient first underwent an incisional biopsy. Microscopic examination revealed the characteristic triphasic lesion, consistent with the morphological and immunophenotypic features of FHI. We followed the lesion clinically and with interval U/S and MRI. The lesion gradually increased in size, being approximately 8.6 x 10 cm by MRI one year after the diagnosis. At that time, it was accompanied by profuse hyperhidrosis of the overlying skin, which caused distress on the parents and caretakers. A complete surgical excision was then performed. She recovered well from the operation and at 11 months of follow up has no signs of recurrence. Although rare, FHI can be associated with localized profuse hyperhidrosis. Complete surgical excision, if possible, should be considered in cases of debilitating hyperhidrosis.