Pyogenic granuloma under nail: A rare localization

Abstract

Pyogenic granuloma (PG) – also known as lobular capillary hemangioma – is a benign vascular tumour that occurs on the skin and mucous membranes, it’s can arise spontaneously, in sites of injury, or within capillary malformations [1]. Because malignant tumors, such as amelanotic melanoma, can be misdiagnosed as PG, histopathology is mandatory for the correct diagnosis, even though dermoscopy can play a primary role in the prompt recognition of PG, showing highly repetitive patterns that can support the diagnosis [2]. In particular, the presence of reddish homogeneous area, white rail lines are strongly suggestive of PG; even more so when associated together. On the other hand, with dermoscopy, it is not uncommon to detect ulceration and vascular structures that do not rule out malignancies [3]. Vascular structures are observed in 45% of cases, they can be linear-irregular or polymorphic and atypical [2]. Despite its benign nature, GP can have a significant negative impact on patients’ quality of life, and therefore appropriate therapy is needed. This is a 35-year-old patient with a history of trauma to his left hand dating back 3 months before his admission. He presents with a nodule under his left thumb, which has been evolving for 2 months, fixed in depth and sometimes-bleeding (Fig. 1). The nodule was slightly painful. X-rays of the thumb were normal. On dermoscopy (Fig. 2), we noted the presence of vascular lagoons with fibrous septal and linear vessels. We suspected a botryomyoma or achromic melanoma. Surgical excision was performed (Fig. 3) with an anatomopathological study in favour of a pyogenic granuloma.