Surgical Management of Difficult Nail Glomus Tumors Free

Nail glomus tumors (NGTs) arise from the glomus bodies, located in the subcutaneous, and are considered benign mesenchymal neoplasms (2% of the soft tissue tumors/hand tumors) [1]. The first publication refers from the 1800s, describing the tumor as a painful subcutaneous tubercle [2]. Although not frequent, and probably misdiagnosed, it is one of the best-known nail tumors since its symptoms are very characteristics.

It usually affects the nail matrix and the proximal nail bed area of women’s fingers and is capsulated. The clinical aspects are variables and may include not only a bluish area/papule/nodule affecting the nail bed/matrix area but also a longitudinal erythronychia, split of the nail plate, over curvature of the of the nail, and even nail dystrophy (Fig. 1). Pain is typical for this tumor; it is intense, pulsating, and can be triggered by minor trauma, cold, or even spontaneously. The classical triad is represented by severe pain, pinpoint tenderness, and cold sensitivity [3‒5].

Love’s pin test [6] is characterized by triggering a severe tenderness pain after punctual compression above the tumor, which can get the patient withdraw the hand. On the other hand, Hildreth’s test [7] is described as a pain improvement observed after the compression at the base of the painful digit (tourniquet) [8, 9]. Many diagnostic tools are described in the literature to identify, localize, and characterize these tumors, such as dermoscopy, transillumination, X-ray/computerized tomography, ultrasound, magnetic resonance imaging, thermography, dynamic thermography, dynamic optical coherence tomography, arteriography, and angio-MRI [10‒17], but Love’s pin test is simple, cheap, precise, and rarely fails.

NGT is treated with complete surgical excision. The traditional approach is described as the tumor exposure after partial or total nail avulsion and the nail matrix/bed transection. Usually, it is an easy and not demanding procedure since the tumors are mostly encapsulated and well delimited. Mishaps can occur and are generally related with recurrence (up to 35%) and nail dystrophy [18‒20].

During our daily personal and academic surgical practice, we noticed that some of the NGTs could be considered “difficult” ones. As dermatological surgeons, we should be aware of these challenging cases, in order to get a complete removal of the tumor and low rates of nail dystrophy after the procedure.

NGT may be a pitfall, especially by two main reasons: tumor’s feature and surgeon’s skills/expertise (Table 1). The tumor’s features that can make an NGT be considered as a difficult one are location, small and multiple tumors, and non-capsulated lesions. On the other hand, some choices can put the surgeon in a difficult situation, compromising the tumor’s removal and/or increase the risk of nail dystrophy, such as the blanching area produced by the distal block anesthesia, “tiny” surgical approach, wrong or not delicate surgical tools, and Mohs surgery.

Mostly, subungual glomus tumors are in the submatricial area, followed by the area beneath the nail bed [21], but in some cases, it can be found nearby the lateral horn of the nail matrix (Fig. 2), digital pulp (Fig. 3), or even deeply attached to the periosteum of the distal phalanx (Fig. 4). For these cases, preoperative image tests are required for a better and precise localization of the lesion, in order to determine the best surgical approach.

Small NGTs can be observed in early stages, or recurrence lesions, and result in situations where the image tools sometimes cannot identify the lesion. Surgical removal is very difficult due to the approach, incision, and localization of the tumor (Fig. 5). In these cases, Love’s pin test and marking the lesion before anesthesia are practical and useful tools that can really help us, even for this case where the symptoms are less intensive than the usual tumors. Sometimes, microscopic tools [22], bigger incisions, or en block excisions are required for the complete removal of the tumor (Fig. 6).

Multiple tumors can be found in two situations: associated with neurofibromatosis [23‒29] or synchronously [30]. For multiple excisions in different digits, many conditions and steps must be respected in order to ensure a safe and effective procedure occurs, such as preoperative preparation, anesthesia considerations, intraoperative logistic (tourniquets/tools/dressing), and postoperative daily restrictions (Fig. 7). Rarely, two tumors can be found in the same nail unit, and the exact location must be identified by image tools to ensure a complete removal of the lesions (Fig. 8). Although almost all NGT are capsulated, just a few and particular cases can be non-capsulated (Fig. 9), making dissection of the tumor impossible, demanding a wider incision and/or an en block excision.

Clinically, NGT can appear in many ways, but the reddish-bluish coloration also helps us to determine the correct spot of the surgical incision, just after the partial or total nail avulsion. Distal block anesthesia can produce a blanch area in the nail unit and efface the reddish-bluish area produced by the tumor. For that, proximal block anesthesia or even some guidance points are recommended prior to the anesthetic infiltration, in order to keep the surgeon aware of the perfect spot for the incision (Fig. 10). Transillumination can also be used prior to or even during the procedure to help “finding” the tumor (Fig. 11).

Many papers have been published reporting different surgical approaches to remove NGT. Usually, the techniques describe methods that involve tiny partial removal of the nail plate prior to the tumor removal [21, 22, 31, 32]. Those are quite charming since it can guarantee a painless and more comfortable postoperative period, with less risk of a nail dystrophy, and challenges the surgeon skills. Back to the aim, of the removal of the tumor, those techniques should be chosen based on the surgeon skills, to prevent incomplete removal of the lesion.

The removal of NGT is considered a delicate surgery and requires some skills/expertise of the surgeon. But even a well-trained surgeon can face some difficulties when wrong instruments are provided and more than increase the chance of postoperative nail dystrophy, where high rates of recurrence can be observed. Preparing yourself with delicate and useful surgical instruments will ensure a smooth and safety procedure, and do not forget that a tourniquet is necessary since a bloodless surgical field is mandatory (Fig. 12, 13).

Mohs micrographic surgery is an important technique that has become more and more popular among dermatologists and other specialties. Recent publications report the technique as an option to treat not only malignance of the nail unit but also benign lesions, and the glomus tumor is not out of that. The Mohs technique was reported as a treatment option for subungual glomus tumor [19, 20], with high cure rates, but some considerations must be taken in account before choosing the technique. First, the costs are quite higher than a conventional surgery. Second, technically, it is considered difficult and more than 2 stages are necessary since the rupture of the capsule is frequent during the debulking, and finally, there are no reports supporting that the Mohs technique has higher cure rates when compared with conventional surgery. Mohs surgery may be considered as an option for recurrent lesions.

NGTs are a well-known lesions that usually are easily removed, but paying attention to some situations prior to surgery, and avoiding putting ourselves in tough situations, will ensure a complete removal of the tumor, with less chance of nail dystrophy and recurrence.

The authors have received a written informed consent for the publication of all the images attached into this manuscript.

The authors have no conflicts of interest to declare.

This study was not supported by any sponsor or funder.

Nilton Di Chiacchio and Nilton Gioia Di Chiacchio contributed to all aspects of the productions of this manuscript.