Purpose: Tumorous conditions of the hand are frequently encountered by hand surgeons. Deep palmar tumors of the hand are very rare, reported cases were usually benign, but the most important issue is frequent anatomical variations with challenging surgical exposure and excision of these lesions. When we review the literature, only case reports or small series of patients were reported. The aim of this study was to demonstrate our experience with the deep palmar tumors of the hand. Materials and Methods: A multicenter retrospective analysis was designed. Medical records were reviewed with searching the database of two hospitals. Fifty-one cases were identified who were operated between the period of January 1998 to May 2015, and patients were invited for final examination. Forty-three patients who were available for the final follow-up examination were included in the study. All patients were evaluated with physical examination and preoperative magnetic resonance imaging (MRI) for surgical planning; x-ray studies were obtained if necessary. Recurrences were confirmed with physical examination and MRI. The analyzed parameters include age, gender, localization, preoperative symptoms, size, site, treatment methods, histopathologies, complications of surgery, and recurrences. Palmar space was divided in to five zones: thenar, carpal tunnel, hypothenar, distal radial, and distal ulnar. Statistical analyses were performed. Results: The mean age at the operation was 38.5 (9-83). Twenty-one (49%) male and 22 (51%) female participants were included in the study. Nineteen (44%) right and 24 (56%) left hands were involved. The most common preoperative symptom was enlarging mass in all patients (100%) followed by nerve compression in 24 patients (44%; 2 motor involvement at Guyon canal), functional impairment in 12 patients (28%), pain in 5 patients (12%), and pruritus in 1 patient (2.3%). The mean follow-up period was 56.7 months (12-168). All 43 pathologies were benign, and there were 10 lipomas (23.3%), 8 ganglions (18.6%), 5 giant cell tumor of the tendon sheath (11.6%), 4 schwannomas (9.3%), 3 hemangioma, 3 palmar fibromatosis, 2 epidermal cysts (4.6%), 2 neurofibroma (4.6%), 1 angiolymphoid hyperplasia with eosinophilia (ALHE) (2.3%), 1 granuloma, 1 calcifying aponeurotic fibroma (CAF), 1 digital fibroma, 1 foreign body granuloma, and 1 lipofibromatous hamartoma. The most common complication was temporary numbness, and paresthesias of the digital nerves were detected in 10 (23%). Only 3 (7%) recurrences (2 ganglions and a lipoma) were observed in the postoperative first year. Two cases were re-operated and one case with ganglion was refused reoperation and followed up with the recurrence. Iatrogenic arterial injury in 2 patients (4.6%) were primarily repaired intraoperatively, local tenderness in one patient (2.3%), weakness of fifth finger adduction in one patients, and stiffness of index finger in one patient. Conclusion: Updated knowledge and understanding nature and demographic characteristics of the tumorous conditions of the hand is crucial for an accurate diagnosis and appropriate treatment. In the deep palmar space of the hand, tumors usually occurs close relationship between tendons, muscles, nerves, and vascular structures. Preoperative MRI is essential for the diagnosis and the successful surgical planning.
