Giant Subcutaneous Solitary Gardner Fibroma of the Head of a Bulgarian Child
We present the case of an 8-year-old white male patient who was seen by a dermatologist for a tumor-like formation located in the occipital region. The lesion had been present since birth and was initially misdiagnosed as a lymphangioma or hemangioma, based on its small size (1 cm in diameter), soft texture on palpation, and the ultrasonography findings. No further therapeutic interventions had been initiated at that time and the patient was being monitored. According to the mother's history, instead of decreasing, the formation has increased in size over the years, most obviously during the last year and a half, and the structure had become firmer on palpation. No accompanying symptoms were noticed. No family history was reported, nor were there comorbidities or medications. On clinical examination, there was a poorly circumscribed, firm, rubbery, plaque-like tumor on the left occipital region, measuring approximately 4–5 cm in greatest dimension (Fig. 1A). The conducted laboratory blood tests did not revealed any abnormalities. Computerized tomography and angiography revealed a solid tumor formation, with homogeneous density, sharp and smooth margins, well vascularized, which did not affect the underlying bone structure (Figs. 2A–C). No intracranial involvement was established (Figs. 2A–C). The patient was sent to neurosurgery, where total excision of the tumor was performed under general anesthesia. The wound edges were closed with single sutures (Fig. 1B). Histopathologic examination of the tumor revealed a hypocellular lesion which comprised thick, haphazardly arranged collagen bundles, bland-appearing fibroblasts, and small blood vessels in a plaque-like growth pattern with infiltration of adjacent structures (Figs. 3A–C). Positive nuclear staining for beta-catenin was observed by immunohistochemistry. All of these findings supported the diagnosis of Gardner fibroma (GAF). The postoperative period proceeded without complications, and no other evidence of fibroma was seen in other internal organs or structures. The parents refused genetic analysis. An every 6-month monitoring schedule was instituted.
GAF is a rare benign soft tissue tumor, usually presenting in children and young adults.1 Its typical histological presentation includes haphazardly arranged coarse and hyalinized collagen bundles combined with loosely arranged, bland spindle cells.2 A predilection for childhood is reported and an association with familial adenomatous polyposis (FAP) in 90% of the cases.2,3 Forty-five percentage of the patients develop desmoid-type fibromatosis.1,2 Furthermore, this fibroma can serve as an initial clue to the diagnosis of Gardner syndrome, characterized by polyposis coli, osteomas, and various soft-tissue tumors and caused by mutations in the adenomatous polyposis coli gene.3 The disease is an autosomal dominant trait and may present at any age from 2 to 70 years.4 Although the frequency and clinical characteristics of sporadic Gardner-type fibromas versus FAP-associated GAFs have not been clearly established, some authors have postulated that FAP-associated GAFs are actually less common than sporadic GAFs and can demonstrate clinically distinct features.4 In the present case, a solitary subcutaneous GAF in the occipital area was diagnosed in an 8-year-old patient, with no family history or comorbidities. To the best of our knowledge, this is the first such case reported in the literature. No significant data are currently available regarding the benefits of genetic analysis in these cases. Furthermore, the therapeutic behavior and the mandatory screening regimen are the same in cases of sporadic and familial GAF. Since no comparative data regarding the relative prognosis of this tumor are available, we recommend the performance of mandatory screening on an every 6 months basis. The performance of genetic analysis in all cases of sporadic GAF (exemplified by the patient presented here) may falsely reassure the physician and the patient's parents.