# Myoepithelioma of the Hand: A Systematic Review
## 3 Results  
Fifty abstracts met our inclusion criteria. Among those, 35 articles were finally excluded, and 15 were reviewed (Figure 1).  
Figure 1: PRISMA flowchart of articles selection.  
All the reviewed articles were case reports, each describing a single case of myoepithe-lioma in the hand or fingers (Table 1).  
The 15 cases comprised nine males (60%) and six females (40%), with an average age of 41.3 years (range 12-69 years). In nine cases [8; 9; 10; 11; 12; 13; 14; 15; 20], the lesion was located on a finger. Of these, five were on the third finger [8; 11; 13; 14], with the second most affected being the second finger, followed by the fourth. No cases were described on the first or fifth fingers. For the five cases involving the hand [9; 16; 18; 21; 22], three were located in the hypothenar region [16; 18; 21] and two in the thenar area [9; 22].  
All patients, except one, reported no pain. The single patient who reported pain had a history of trauma to the same digit [20]. The mass was consistently described as firm and solid with no distinctive characteristics, except in one case where it was described as a carnose, violet-ish lump [10]. Two cases involved carpal tunnel syndrome [9; 19].  
We also included five cases of bony myoepitheioma as the clinical presentation and histological features suggest the same origin.  
In four cases [8; 9; 16; 18], no additional imaging examination was requested. X-ray was the first diagnostic exam requested in the other cases, complemented by MRI in six cases [11; 14; 15; 17; 21; 22] and ultrasound (US) in three cases [10; 11; 19]. A CT scan was requested in two cases [11; 21] to assess bone involvement. A PET scan was used in one case [22], showing a mass with malignant-like features.  
The S-100 protein was always positive, followed by cytokeratin AE1/AE3 and EMA, which were negative in three cases only [14; 17; 21]. Other markers that tested positive included vimentin, calponin, and p63.  
In one case, an excision biopsy was performed before complete excision due to the suspicion of malignancy [17]. In all other cases, clear margin excision was performed. For the four cases involving bones [13; 14; 17; 20], complete bone resection was performed in two cases, simple curettage in one case, and curettage followed by bone grafting in another. The average follow-up was 10.2 months, with one case [17] of recurrence observed, which resulted in ray amputation (Table 2).  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Author** & **Year** & **Age** & **Gender** & **Localization** & **Clinical Presentation** & **Differential Diagnosis** \\ \hline [PERSON] [8] & 2013 & 52 & M & 3D & Firm, painless popular lesion & / \\ \hline [PERSON] [9] & 2009 & 36 & M & TE & Firm mass attached to the FDD/CTS & Ganglion/PVNS \\ \hline [PERSON] [10] & 2024 & 12 & F & 2D & Violet, carnose lump & Dermoid Cyst \\ \hline [PERSON] [11] & 2023 & 15 & M & 3D & Firm mass & Lipoma \\ \hline [PERSON] [12] & 2022 & 52 & M & 2D & Firm painless mass & Vascular tumor emboli (pleomorphic adenoma) \\ \hline [PERSON] [13] & 2017 & 33 & M & 3D & Soft tissue swelling & Enchondroma \\ \hline [PERSON] [14] & 2016 & 37 & F & 3D & Hard swelling & Enchondroma \\ \hline [PERSON] [15] & 2014 & 69 & M & 2D & Enlarging mass & GCT \\ \hline [PERSON] [16] & 2020 & 52 & M & HE & Painless growing mass & / \\ \hline [PERSON] [17] & 2015 & 28 & F & 2D & Slowly enlarging tender mass & Chondromyxoid fibroma \\ \hline [PERSON] [18] & 2011 & 51 & M & HE & Painless growing mass & / \\ \hline [PERSON] [19] & 2011 & 35 & F & TE & Firm mass + CTS & Chondromyxoid fibroma \\ \hline [PERSON] [20] & 2011 & 29 & M & 4D & Painful post-traumatic mass & / \\ \hline [PERSON] [21] & 2006 & 50 & F & HE & Slow growing mass & / \\ \hline [PERSON] [22] & 2006 & 69 & F & TE & Slow growing mass & Malignant neoplasm \\ \hline \end{tabular}
\end{table}
Table 1: Included articles and main characteristics.