Nodular hidradenocarcinoma of the forehead presenting as a lipoma: A case report with a review of literature

INTRODUCTION: Hidradenocarcinoma is an uncommon slow-growing malignant tumor that originates from sweat glands, it is most seen in the head and neck, and present typically as hard asymptomatic nodule. Diagnosis is confirmed by histopathology and immunohistochemistry, and wide local excision is the mainstay of the treatment. In our study, we discuss the approach and management of this rare disease, with focusing on the importance of histopathology in diagnosing such cases. PRESENTATION OF CASE: We present a very rare case of a 58-year-old female who presented with painless slow growing forehead swelling for 2 years, with clinical feature suggestive of lipoma. The patient underwent surgical excision, and post-operative histopathological examination of the specimen was consistent with nodular hidradenocarcinoma. DISCUSSION: Hidradenocarcinoma is a very rare malignant tumor that was first reported in 1954. This tumor was reported to be more common in males, and the incidence increases with age. The origin of hidradenocarcinoma is mostly de novo. The definitive diagnosis requires histopathological examination, and wide local excision is the mainstay of the treatment. CONCLUSION: Hidradenocarcinoma is a very rare sweat gland malignancy, and the diagnosis can be challenging. In our study, we emphasize the importance of raising the awareness among the surgical oncology society regarding this rare tumor, and we discuss the approach and management of such an uncommon disease, with focusing on the importance of histopathology in diagnosing such cases.