抄録
Two cases of reconstruction with a reversed forearm flap of the defect in which the bone was exposed were reported.
Case 1: A 77-year-old male had a malignant melanoma on his right thumb. The nail had completely fallen off and an ulcer on the irregularly pigmented nail bed tended to bleed markedly (Fig. 1) .
Regional or systemic lymph node swelling was not noticed and no signs suggestive of metastasis were found. The tumor was widely resected with 4 to 5mm free margin and the right thumb was amputated at the level of the interphalanx joint (Fig. 2) . The defect in which the thumb proximal phalanx was exposed was reconstructed with a right reversed forearm flap (Fig. 3) . Pathologically, the tumor was a completely resected malignant melanoma with Clark level III, 1mm tumor thickness (Fig. 4) . Prophylactic right axillary lymph node dissection was performed thereafter. Pathologically, the right axillary lymph nodemetastsis was not revealed. TNN classification of the tumor was pT2, pN0, M0; stage I a.
Case 2: An 81-year-old male had a malignant melanoma on his right index finger. On the volar side of the finger a wide brown to black pigmented lesion with central painful ulceration was noted (Fig. 6) . One small right axillary lymph node was palpable. No signs suggestive of metastasis were found. The tumor was widely resected with 5mm free margin and the index finger was amputated at the level of distal 1/3 of the second metacarpus (Fig. 7) . The defect in which the stump of the second metacarpus was exposed was reconstructed with a right reverse forearm flap (Fig. 8) . Pathologically, the tumor was a completely resected malignant melanoma with Clark level IV, 3.10mm tumor thickness (Fig. 9) . TNN classification of the tumor was pT3b, pN0, M0; stage II.
In the above two cases, the reversed forearm flaps completely survived and the reconstructed hands have both satisfactory function and appearance (Figs. 5 and 10) .
We believe that a reversed formed flap is the best choice of treatment for defects in which the bone, nerve or vessels are exposed after resection of the malignant skin tumors on the hand, because this flap is able to be elevated easily and safely and therefore shortens operating time. These reasons are beneficial all the more in cases of aged patients with many complications. In addition, a reversed forearm flap is able to be transplanted with nervus cutaneus antebrachii lateralis, musculus palmaris longus or radius involved. In cases doubtful of any regional lymph node metastasis, however, a reversed forearm flap should not be used.
