The Rare Occurrence of a Solitary Collagenous Fibroma in the Gingiva of a 2‐Year‐Old Child: A Case Report

Background Desmoplastic fibroblastoma (DF), or collagenous fibroma (CF), is a distinct and rare benign soft tissue tumor, clinically presenting as a slow‐growing firm mass originating from fibroblastic and myofibroblast cells. The exact cause of CF remains unknown, and it is considered a sporadic lesion without any known genetic or environmental risk factors; hence, it is considered a true neoplasm. Case Report The occurrence of CF in the general pediatric population is inherently rare, and this case report describes the very rare occurrence of a CF in the gingiva of a 2‐year‐old child and its management. This case report includes the clinical, radiographical, and histological findings and management of a child having a solitary, well‐circumscribed, oval, firm, lobulated, sessile overgrowth in the gingiva of the labial aspect of the mandibular primary central incisors, causing displacement of the teeth and difficulties in closing the mouth and chewing food. The lesion was excised using a diode laser and examined histopathologically. Hematoxylin and eosin‐stained sections exhibited dense fibrous connective tissue randomly distributed in long and circular collagen bundles with spindle‐shaped to stellate‐shaped fibroblasts. The superficial part of the connective tissue shows inflammatory cell infiltration, adipocytes, and proliferating blood vessels in between the rete ridges. Masson’s trichrome stain revealed positive for collagen and a few areas positive for muscle. Immunohistochemically, the lesional areas were negative for alpha‐smooth muscle actin (SMA) and positive in the areas surrounding blood vessels. This case highlights the importance of considering CF in the differential diagnosis of soft tissue masses and emphasizes the role of histopathology in establishing a definitive diagnosis. Conclusion Laser surgical excision and timely management help achieve favorable outcomes, considering the functional and esthetic aspects. Incomplete removal may lead to recurrence, emphasizing the importance of achieving clear surgical margins. This case contributes to the limited literature on CF and aims to improve clinical awareness of this uncommon entity.