Recurrent cutaneous metaplastic synovial cyst

Unprecedented recurrence of carpal tunnel syndrome by metaplastic synovial cyst in the carpal tunnel

Metaplastic synovial cyst (MSC) is a benign cystic lesion observed after surgical intervention and recurrent skin trauma. Because of its rarity, the etiology is not fully understood. The most emphasized etiologic factors are recurrent surgical procedures and cutaneous pathologies, which cause cutaneous fragility and abnormal wound formation. In the literature, MSC is exemplified as a mass that can be observed by the naked eye and palpated. All patients had a history of previous surgical procedures in the area. In the present case, we report a 48 -year-old woman with recurrent carpal tunnel syndrome due to a MSC. This report showed that MSC can be detected at deeper locations than the regions described in the literature. To our knowledge, this is the first report of MSC causing carpal tunnel syndrome recurrence. It is thought that previous operations are the most important etiologic factor in MSC occurrence.

Cutaneous Metaplastic Synovial Cyst: Case Report and Literature Review from the Dermatological Point of View

Cutaneous metaplastic synovial cysts (CMSCs) are rare tumors typically comprising a solitary, well-circumscribed cystic mass that is not connected to the joint. Synovial cysts have been reported predominantly by orthopedists or pathologists; however, the presence of CMSC is not generally well recognized by dermatologists. Herein, we report a CMSC in a 68-year-old woman receiving systemic corticosteroid therapy for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA). We attempt to delineate the clinical characteristics of this unusual neoplasm by reviewing the literature, focusing especially on dermatological descriptions. Histologic examination of the surgical specimen in the current case revealed that the cystic wall was lined with layers of flattened synovial cell-like cells and connective tissues, mimicking the synovial membrane. Positive immunoreactivity of the lining cells against vimentin was detected, but no immunoreactivity against cytokeratin, carcinoembryonic antigen (CEA), CD68, or S-100 was detected. The pathogenesis of CMSC remains unclear, but it has been tightly linked to direct traumatic stimuli or relative tissue fragility, which potentially accounts for CMSC development in our case. Most CMSCs reported by dermatologists are located on the extremities, whereas those described by other specialists tend to be distributed more globally. Preoperative diagnoses are often either epidermal cyst or suture/foreign body granuloma. Incomplete surgical excision of usual synovial cysts may lead to local recurrence, which has been reported in oral and maxillofacial surgery, but not in dermatologic surgery. This fact could be explained by the technical difficulties of surgical excision related to anatomical location. Dermatologists need to be aware of CMSC, and CMSC should be included in the differential diagnosis of subcutaneous cysts.

Cutaneous Metaplastic Synovial Cyst: A Case Report and Literature Review

Introduction:

Cutaneous metaplastic synovial cyst (CMSC) is a rare cutaneous lesion characterized by a tender subcutaneous nodule, which usually occurs at the site of previous surgical or local trauma. Histologically, the lesion includes a cystic structure with villous-like projections and a lining mimicking hyperplastic synovium.

Case Presentation:

We reported the first case of CMSC which developed at the surgical incision site of treatment of a maxillofacial fracture. In addition, we reviewed English literature to evaluate all previously reported CMSC cases and discussed its clinical and histopathological features and etiology. From 1987 to now, reviewing the English literature about CMSC includes 17 studies that described 28 cases, and our presented case was the 29th. There was no sex predilection and age of patients ranged from 7 to 82 years, but most of them were over 40 years. We can see this lesion in any site of the body and hand/arm is the most prevalent involved region (28% cases). Most of the patients had a history of previous local trauma or operation in the involved area.

Conclusions:

Although the actual etiology of CMSC remains unclear, trauma, as the most probable etiologic factor, plays a role in development of CMSC. Surgical excision of the lesion is the preferable treatment choice and rate of recurrence is low.

Cutaneous metaplastic synovial cyst of the cheek generated by repetitive minor trauma

Cutaneous metaplastic synovial cyst (CMSC) refers to a cyst lined by metaplastic synovial tissue including villous structures. It is thought to be a tissue reaction to local trauma, and most cases have a history of preceding surgery or trauma. Clinically, most of the lesion is a tender intradermal nodule that is associated with scar tissue. However, dermatologists have difficulty in diagnosing CMSC because CMSC is reported only rarely and its clinical manifestation can be confused with implantational epidermal cyst, suture granuloma or other cutaneous cysts. Thus, a histopathological exam is mandatory for diagnosis of CMSC. Herein we report the case of an 18-year-old man who developed CMSC on the left cheek on the posterior ramus of the mandible. He had a history of repetitive digital manipulation of the lesion before the onset of CMSC.

Cutaneous metaplastic synovial cyst of the first metatarsal head area

A cutaneous metaplastic synovial cyst (CMSC) is a cyst lined with metaplastic synovial tissue, which includes the formation of an intracystic villous structure resembling hyperplastic synovial villi. Clinically, the lesion is a tender, subcutaneous nodule that usually occurs at the site of previous surgical trauma and is frequently misdiagnosed as a suture granuloma. The actual cause remains unclear; however, trauma is presumed to be a precipitating factor, as most reported cases have demonstrated a history of antecedent cutaneous injury. Here, we present a case of CMSC in a 51-year-old woman who presented with a cystic mass localized in the left sole. She had no history of previous trauma or surgical procedures performed in the area. Although the case explained in this report is a spontaneous case of CMSC that occurred without a history of trauma, it is believed to have been caused by constant and chronic pressure since CMSC occurred in the first metatarsal head area, a part of the sole where heavy pressure is consistently applied.