Dermoid sinus (DS) is a rare congenital cutaneous malformation resulting from incomplete separation of the ectoderm from the neural tube during embryogenesis and is most commonly encountered in dogs along the dorsal midline. Atypical regional occurrences, including cranial localizations, are rare and may pose diagnostic and surgical challenges. This report describes a four-month-old male Pomeranian dog presenting with multiple progressive swellings within the parieto-occipital region of the head. Physical examination revealed firm, poorly demarcated masses without active drainage. Routine hematological and biochemical parameters were unremarkable. Surgical management consisted of complete excision of the lesions followed by reconstructive closure using a random-pattern advancement skin flap due to the extensive skin defect. Histopathological evaluation demonstrated a closed epithelial-lined lesion lacking communication with the epidermal surface, consistent with Type V DS, considering its localization within the parieto-occipital region of the head, the lesion was classified as subtype “b” (Type Vb DS). The postoperative course was uneventful, and no recurrence or wound healing issues were detected during the 12-month follow-up period. To the best of the authors’ knowledge, this represents the first documented report of Type Vb DS in a Pomeranian dog with detailed long-term postoperative follow-up. These findings emphasize the importance of thorough surgical excision and appropriate reconstructive planning when managing extensive DS lesions in atypical cranial regions.
Saylak et al. (Mon,) studied this question.