Glomus tumor is an uncommon benign neoplasm that develops in the glomus, a component of the dermis responsible for regulating temperature in the cutaneous microvasculature (1–3). This type of tumor typically manifests in the extremities, primarily in the fingers of the hands and feet (4), although it can also occur in other areas of the body (5–8). Normally, its size ranges around 1 cm in diameter, although cases of smaller size have also been reported (4, 9), which can be challenging to detect, especially in the early stages (3, 10). Consequently, delays in diagnosis are common (11). It is important to note that malignant transformation of glomus tumor is extremely rare, occurring in only 1% of cases (12, 13). However, careful clinical differentiation from subungual melanoma remains essential due to their potentially similar presentations (14, 15). Generally, glomus tumor affects approximately 75% of cases in the subungual region of the hands (16) and is more frequent in middle-aged women, aged between 30 and 70 years (3, 4, 17–19). The symptoms of glomus tumor include sensations of cold or heat in the affected finger (20, 21), accompanied by intense paroxysmal pain (17). Suspecting the presence of a glomus tumor is warranted if the patient experiences the characteristic triad of intense pain, extreme sensitivity especially against the change of environment temperature, and color changes of nail plate, particularly in the fingertips (11, 20, 21). The pain often becomes so intense that it affects the patient’s quality of life (9, 22), even impairing sleep (13). Additionally, as the tumor grows in size, it can deform the nail or bone (16). Additional diagnostic techniques comprise the Love test, Hildreth test (19), assessment of cold sensitivity, and employment of transillumination (4, 9, 16, 20). The Love test entails the utilization of a precise instrument to elicit pain in the affected area while observing the absence of pain in the surrounding unaffected regions. This method exhibits a sensitivity of 100% but low specificity. Conversely, the Hildreth test involves the application of a tourniquet to the affected limb and inflation to 250 mmHg. In a positive test, a reduction in pain over the lesion is expected upon tourniquet inflation, followed by a sudden rebound of pain in the lesion upon release of the tourniquet valve. The Hildreth test is estimated to possess a sensitivity of 92% and a specificity of 91% (13, 18). Imaging diagnosis comprises ultrasound, computed tomography, and magnetic resonance imaging (3, 23), although additional tests such as X-rays, angiography, and ultrasound can be performed to obtain a more detailed diagnosis (3). At present, surgical removal is the sole treatment option for glomus tumor (6, 13). However, its management is challenging due to the small surgical field, and attempts are often made to perform conservative excision in order to preserve the nail matrix (21). Nevertheless, current surgical approaches have inherent limitations (3, 16). In this study, we introduce the microscopic transungual surgical approach, which aims to mitigate these limitations and improve the treatment outcomes.

A total of 61 patients with glomus tumors were included in the study, comprising 49 females (80.3%) and 12 males (19.7%). The median age of the overall sample was 39 years. Median age was 37 years for males and 39 years for females. The median disease duration was 5 years, with an interquartile range (Q1–Q3) of 3 to 10 years (Table 2). Regarding the location of the glomus tumor, we found that 24 (39.3%) were located in the thumb, 9 (14.8%) in the index finger, 9 (14.8%) in the middle finger, 14 (23.0%) in the ring finger, and 5 (8.2%) in the little finger. In terms of the clinical characteristics of glomus tumors, we found that 60 (98.4%) of the patients experienced inadvertently severe pain, 58 (95.1%) of the patients tested positive on the Love test, 31 (50.8%) tested positive on the Hildreth test, 54 (88.5%) tested positive on cold stimulation experiments, and 5 (8.2%) tested positive for heat sensitivity. Furthermore, regarding comorbidities associated with glomus tumors, it was found that 31 (50.8%) presented nail deformities, 24 (39.3%) showed bone changes, and 11 (18.0%) had skin changes. Follow-up was conducted for all patients, 49 (80.2%) of them reported a satisfying recovery of the nail plate. And 3 (4.9%) of them experienced recurrences. More detailed data are included in Tables 1, 2.

The glomus tumor typically presents as a solitary entity (3) and is commonly located in the central proximal region (19). The transungual method provides a wide surgical field of vision and the benefit of accurate exposure to the tumor situated in the central area. However, on account of the limited accommodation of the subungual tissue, general surgical procedure can lead to postoperative nail deformities due to damage to the nail bed, resulting in a high incidence of nail deformities following the procedure (2). Inadequate surgical technique can cause nail deformities and increase the risk of tumor recurrence (4). The transungual approach improves tumor exposure and facilitates complete removal, thus reducing the risk of local recurrence (4, 18). However, this procedure entails complete nail extraction to access the glomus tumor, which can have negative cosmetic repercussions and severely damage the nail bed. Furthermore, if nail bed sutures are not performed carefully, they may cause nail deformities after surgery (3). Complete excision of the nail is the most effective method for full access to the tumor but can result in cosmetic issues and require the entire nail to regrow, leading to patient discomfort (18, 20). In the transungual approach, the removal of the nail plate is performed first, followed by a longitudinal incision in the nail bed and/or the nail matrix to extract the tumor. While this approach provides good visualization and precise tumor localization, it can also induce iatrogenic nail deformities ranging from a longitudinal ridge to complete nail division (27).

The lateral subperiosteal approach is preferable for glomus tumors located in the lateral zone. It is not effective in exposing centrally located tumors (2, 4). Among its advantages is the reduced risk of nail deformity (27), but it is limited by the nail’s location, making the procedure more complex. Occasionally, it can cause nerve damage (3, 16, 20). This type of surgery does not involve nail removal; however, it can sometimes lead to finger or fingertip deformities. The occurrence of these issues can be minimized depending on the glomus tumor’s location and the surgeon’s expertise (20). In some cases, this surgery may leave a tender sensation in the scar area, although it usually improves within 3–4 weeks (20). The surgical field is smaller than in the transungual approach, therefore, it reduces the risk of nail deformity. However, if the excision of the glomus tumor is incomplete, there is a higher risk of recurrence (27). In the literature, other approaches are also described, such as the modified periungual approach method. It involves making an L-shaped excision over the periungual area to the mid-lateral line. However, this method appears to be suitable only for tumors located in the marginal subungual region and requires a significant amount of time and skilled surgical techniques. Additionally, postoperative nail deformity may be more frequent than expected (27). Upon tumor removal, symptoms are alleviated or disappear (18), and typically there are no recurrences or complications (3). Tumor recurrences often occur if the tumor excision has not been complete (2). Therefore, it is necessary to remove the entire tumor in one procedure, with careful attention to detail (1, 3, 20). According to Kim et al., there does not appear to be a statistically significant difference in tumor recurrence based on the type of surgery (2). However, this is still a topic of debate due to the limited number of studies available on this subject. An innovative and current technique for addressing subungual glomus tumor is microscopic excision. This technique is considered superior in terms of recurrence prevention (16). Its advantages include preservation of finger function, nail esthetics, and increased patient satisfaction (16). Lambertini M reported that Mohs micrographic surgery can reduce the risk of recurrence, and annoying symptomatology. More researches are required for the conclusion of the outcome compared to other techniques (28). Minimally invasive transungual technique provides a small window for excision of digital glomus tumor. This technique brings benefits of fast recovery and satisfactory from patients for the minimal trauma of the nail unit (29). However, the exposure is limited, especially under the circumstance of large size tumor. By our procedure, tumors are excised precisely with assistant of microscope. And the careful avulsion and reposition of the intact nail plates bring satisfying recovery and cosmetic outcome by our result. An incision is made based on the tumor’s anatomical location (4). Additionally, performing an incision according to the anatomical location, providing appropriate anesthesia, and using a pneumatic tourniquet enhance tumor visualization and facilitate its removal, reducing the risk of postoperative complications (16). Meticulous repair of the nail bed after tumor excision reduces the risk of nail deformities (18). Careful dissection with the use of a microscope is helpful in completely eliminating the tumor and distinguishing lesions in the pulp from the surrounding tissue during surgery, providing a more precise tumor delineation. Moreover, this approach allows for meticulous handling and repair of the nail bed tissues (2). Bae et al. suggest in their study that the eponychial flap elevation method could be used as it may minimize nail dystrophy, minimize nail bed damage, as well as postoperative damage (30). However, we have only found one article on the use of this technique in glomus tumors, so the information is limited. Although there are no studies on this matter, we suggest that combining this approach with a microscope could enhance the effectiveness of this procedure. MRI is an excellent imaging modality for diagnosing glomus tumors minimum up to 2 mm in size. Typically, a MRI shows the glomus tumor as a central high-signal point surrounded by an area of lower signal intensity (20, 31). MRI can be useful in distinguishing glomus tumors from neuromas, melanomas, hemangiomas, and other foreign bodies (20, 32). It is the most accurate and detailed method (18), but it is costly. Ultrasound is less expensive but also less specific. Ultrasound may significantly underestimate the diameter of a glomus tumor. X-rays are inexpensive but do not reveal much unless there is bone involvement (21). The classic presentation of a glomus tumor is a subungual or periungual nodule of the distal phalanx. Recurrences can occur if satellite lesions were not identified during surgery. These satellite lesions can grow and become symptomatic, requiring further surgical intervention (1). MRI can be used to identify hidden and multiple glomus tumors (1). Although glomus tumors infiltrating the bone are rare, when this occurs, bone removal is also necessary. MRI is recommended if the bone is affected. In such cases, preoperative plain radiographs may also be considered (12). Studies such as Lin et al. report that factors such as changes in skin color in the area where the tumor is located can increase the risk of recurrence. This is because it becomes more challenging to delineate the affected area when there are changes in the skin. The more accurately the glomus tumor area is determined, the lower the chances of recurrence (21).

Among the main advantages of our study, several distinctive characteristics stand out. Firstly, we have included a significantly larger number of patients compared to previous studies (3, 16, 20). All patients in our study were diagnosed and treated following a uniform methodology. Additionally, we conducted both the Love test and the Hildreth test on all patients. All our patients received an intervention based on the Microscopic Transungual Surgical Approach technique. This treatment homogeneity provides us with the advantage of being able to compare results for future investigations. This study describes the surgical technique in detail, with particular attention to the microscopic transungual approach, which has been relatively underreported in the literature. While all included cases were histopathologically confirmed as glomus tumors, not all exhibited the classic clinical trial or uniformly positive diagnostic test results. These findings suggest that magnetic resonance imaging (MRI) serves as a valuable diagnostic tool when combined with clinical investigations. Regarding gender differences, other studies have revealed that, while there are variations in frequencies, a constant remains: the number of women affected by this disease is greater than the number of men (33).

This study has several limitations, including its retrospective design, partial dataset availability, and relatively small sample size, as well lake of incorporating validated patient-reported outcome. Additionally, the absence of a control or comparison group limits the generalizability of the findings (Table 3).

The Microscopic Transungual Surgical Approach could be a promising option for treating glomus tumors. This technique has the potential to minimize the disadvantages associated with other surgical approaches. Further studies are needed to investigate the effectiveness of this surgical technique.

Glomus tumors are rare benign neoplasms commonly found in the subungual region of the hands, often causing intense pain and nail deformities. Surgical removal is the only effective treatment, but existing approaches have limitations such as incomplete tumor excision, nail deformities, and recurrence.

This study evaluates the effectiveness of the Microscopic Transungual Surgical Approach, demonstrating its potential to achieve complete tumor removal while reducing recurrence rates and nail deformities compared to conventional surgical methods.

The findings could influence surgical practice by promoting the adoption of microscopic transungual surgery as a preferred technique for glomus tumor excision, potentially improving patient outcomes and reducing recurrence rates in clinical settings.