Introduction: Lesions that are clinically diagnosed as moles include intermediate malignant lesions, some of which are difficult to differentiate from malignant melanoma. As intermediate lesions require wide local excision and long-term follow-up, we collected cases of excised moles and examined the proportion of such lesions.
 Methods: After excluding obvious malignant melanomas, a total of 329 specimens of lesions clinically or histopathologically diagnosed as acquired melanocytic nevus were extracted. First, we classified them into four types according to the Ackerman's classification. Then, we identified lesions of intermediate malignancies and melanomas.
 Results: The proportion of moles that were classified as Spitz nevus was the lowest of the four types (1.8%), and 66.7% of them were clinically diagnosed as melanocyte nevi. Six specimens were diagnosed as intermediate malignant or malignant (1.8% of the total) requiring differential diagnosis between Clark nevus and Spitz nevus.
 Conclusion: In the treatment of moles, we found lesions that were histopathologically considered intermediate malignant or malignant. In particular, a high proportion of Spitz nevi required differentiation from intermediate malignant lesions. The difficulty of clinical diagnosis, surgical margins, and follow-up period should be noted in such lesions.

 Introduction: Injuries caused by bears have been increasing. In this study, we investigated the characteristics of bear injuries and medical precautions.
 Methods: We retrospectively reviewed medical reports of patients attacked by bears between January 2016 and December 2020.
 Results: Eight males and two females were attacked by bears. The mean age of the patients was 73 years. Most injuries occurred in the morning in October in residential areas (the area between the mountain foothills and arable land, 'Satoyama' area). Many of the patients were attacked in the head, neck, and upper limbs. Facial fractures were observed in more than half of the patients with facial injuries, and soft tissue injuries were observed in all cases. Reconstructive and reparative surgery was performed on the same day as the injury. All patients received prophylactic antimicrobials and there were no cases of infection.
 Discussion: The month, time, and part of the body injured were similar to previous reports, whereas the area where the patients were injured was different. Due to the ecological destruction of the Satoyama area and lack of food, bears are appearing in people's living areas. There is a strong possibility that bear trauma cases will increase in the future; thus, it is important to understand the characteristics of bear trauma for the treatment of bear injuries.

 Morel-Lavallée Lesion (MLL) is a closed degloving soft tissue injury that occurs after trauma. Although it requires early diagnosis and treatment, no standard treatment has been established. We report a 68-year-old male with MLL, who was treated with continuous suction drainage therapy. He was diagnosed as MLL after conservative treatment for traffic trauma of the right lower extremity. The RENASIS^Ⓡ drain accessory, which is used in negative pressure wound therapy, was used as a suction device. The drain was placed from the thigh to the lower abdomen, and suction was applied at -80 mmHg for 15 days. The disappearance of subcutaneous fluid collection was observed 33 days after the injury and no recurrence was observed 3 months after the injury. This procedure may be a useful method for treating MLL because it is surgically less invasive and easier to perform.

 Metronidazole-induced encephalopathy (MIE) is a relatively rare disorder that causes central nervous system dysfunction including cerebellar ataxia and external ophthalmoplegia. We experienced two cases of MIE during the treatment of refractory leg ulcers. The patients' clinical courses, specific magnetic resonance imaging findings, and significant improvement after cessation of metronidazole led to a definitive diagnosis of MIE. There have been a few reports of irreversible loss of consciousness; however, in both the present cases, the symptoms were reversible and improved within a week. Herein, we review the literature relating to MIE and aim to promote the recognition of MIE in plastic and reconstructive surgery.

 Retronychia is a condition of proximal nail plate in growth into the proximal nail fold that is associated with multiple generations of the nail plate, which causes pain and paronychia. It is not widely known and is rarely diagnosed, resulting in few case reports. Herein, we report six cases of retronychia diagnosed in our department between April and December in 2021. All cases were cured immediately by the removal of the total nail plate. Furthermore, postoperative taping of the toe and application of hydrocolloid on nail beds aided good nail growth. Retronychia is suspected when there is refractory proximal nail fold inflammation that is resistant to antibiotics and antifungals. Nail plate avulsion is an effective treatment.

 We herein report a case of facial malformation with a right macrostomia, bilateral accessory auricular appendages, and a left cleft lip and palate. Macrostomia is a symptom of first and second branchial arch syndrome. A three-day-old Japanese boy was referred to our hospital for the treatment of his cleft lip and palate. He had a left cleft lip and palate as well as right macrostomia and bilateral accessory auricular appendages. A clinical diagnosis of first and second branchial arch syndrome complicated with unilateral cleft lip and palate was made. His macrostomia, cleft lip, and accessory auricular appendages were treated at five months old. The clinical course after surgery was satisfactory. Palatoplasty will be performed in the future.

 Pseudoaneurysms rarely occur in peripheral arteries beyond the lower leg. Herein, we report a case of tibial nerve palsy due to the compression of a pseudoaneurysm of the posterior tibial artery caused by trauma. The patient was a 34-year-old man who suffered a puncture wound from glass in the right Achilles tendon area. There was no pulsatile bleeding, and the glass fragment was removed without any problems; however, the patient experienced pain and difficulty walking on day 12 of the injury. It took time to determine the cause, but a pseudoaneurysm was identified on contrast-enhanced computed tomography. We resected the pseudoaneurysm, thereby resulting in symptomatic improvement. In cases presenting with delayed onset of neurological symptoms following an injury, an aneurysm in the accompanying artery should be considered as a possible cause.