Epidermal inclusion cyst of phalanx: a case report and review of the literature

A rare case of chondroblastoma involving the distal phalanx of the ring finger

Chondroblastoma, a rare benign bone tumor, is typically found in the epiphysis of long bones, with hand involvement being particularly uncommon. We present a case of an 11-year-old female with chondroblastoma involving the fourth distal phalanx of the hand. Imaging revealed a lytic, expansile lesion with sclerotic margins and no soft tissue component. A preoperative differential diagnosis included intraosseous glomus tumor, epidermal inclusion cyst, enchondroma, and chronic infection. The patient underwent open surgical biopsy and curettage for both diagnostic and treatment purpose. The final histopathologic diagnosis was chondroblastoma.

Injectable Synthetic Beta-Tricalcium Phosphate/Calcium Sulfate (GeneX) for the Management of Contained Defects Following Curettage of Benign Bone Tumours

Benign and low-grade malignant bone tumours are often treated with curettage and filling of the resultant defect using any of a number of materials, including autologous bone grafts, allografts, or synthetic materials. The objective of this study was to report our experience using a synthetic bone graft substitute in these patients. Ten consecutive cases (four males, six females; mean age, 36 years) of benign bone tumours were treated surgically at a tertiary musculoskeletal oncology centre, between 2019 and 2021. Following curettage, the contained defects were managed with injectable beta-tricalcium phosphate/calcium sulfate (GeneX; Biocomposites Ltd., Keele, UK). The desired outcomes were early restoration of function and radiographic evidence of healing. No other graft materials were used in any of the patients. The mean follow-up was 24 months (range, 20–30 months). All patients in this series (100%) demonstrated radiographic evidence of healing and resumed their daily living activities. There were no tumour recurrences and no complications were encountered with the use of GeneX. In patients with contained defects following curettage of benign bone tumours, we found GeneX to be a safe and effective filling agent. These findings contrast with some existing studies that have reported local complications with the use of injectable beta-tricalcium phosphate/calcium sulfate.

The first case report of an intraosseous epidermoid cyst in the distal phalanx of the index finger with infection resulting in single clubbing finger: A case report and review of the literature

An intraosseous epidermoid cyst at the distal phalanx of the index finger is extremely rare. These cysts are asymptomatic unless ruptured, severely infected, or transformed into malignant squamous cell carcinoma. We present a case of a single clubbing finger in an adult diagnosed with an intraosseous epidermoid cyst in the distal phalanx of the left index finger with no history of pulmonary or cardiovascular diseases. Preoperative MRI showed an expansile lytic lesion with a sclerotic margin. Histopathological examination indicates that there is keratinous cell debris in the cyst with a wall of stratified squamous epithelium, which was the key to the correct diagnosis of an intraosseous epidermoid cyst. Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

A Giant Epidermal Cyst in the Gluteal Region: A Case Report

Epidermal cysts are the most commonly occurring cysts in the subcutaneous plane and are usually asymptomatic, small, and slow growing. When the size of an epidermal cyst is greater than 5 cm, it is considered a giant epidermal cyst. Common etiologies include sun-damaged skin and acne vulgaris, and they can appear anywhere in the body, but preferably over the face, neck, and trunk. Unusual sites include the breast, penis, spleen, bones, subungual region, palms, soles, and buttocks. In this report, we presented the case of a 31-year-old female having a large, painless, gradually progressing swelling for two years in the left gluteal region, which was insidious in onset and slow-growing. The patient eventually described a discomfort that made it impossible for her to sit for long hours or sleep in a supine position. Clinical examination revealed circumscribed mass over the left gluteal region from which diagnosis of giant lipoma was confirmed, but due to its large size and involvement of the whole left buttock, we considered it important to perform an ultrasound examination to reinforce our diagnosis, which revealed a large cystic mass in the left gluteal subcutaneous plane that was excised. As a definitive management, surgery was performed with excision of the swelling, which was extracted in toto and was identified as a cyst, and on histopathological examination, the cyst wall was lined by stratified squamous epithelium. Hence, this case report highlights a rare case of a giant epidermal cyst in the gluteal region.

Diagnosis and Treatment of a Spinal Intraosseous Keratinized Cyst of L1 in a Dog

An 8 yr old female spayed golden retriever presented for a 3 wk history of progressive pelvic limb ataxia. MRI revealed a well-circumscribed T2-weighted hyperintense, T1-weighted poorly contrast-enhancing extradural mass to the right of the spinal cord at the level of L1 causing severe spinal cord compression. A right-sided hemilaminectomy was performed to remove the mass, and histopathology revealed an intraosseous keratinized cyst. A complete neurologic recovery was made within 2 wk following the surgery. This case illustrates a rare diagnosis and the first case report describing MRI findings and favorable clinical outcome after surgical management of a spinal intraosseous keratinized cyst.

Intraosseous epidermal cyst of the great toe that was difficult to distinguish from chronic osteomyelitis: A case report and literature review

Obtaining a correct intraosseous epidermal cyst diagnosis is difficult due to the extreme rarity of this cyst. Further, the clinical manifestations and radiographic findings are very similar to those of a malignancy or infection. Early histopathological analysis is required for accurate diagnosis and for avoiding unnecessary antibiotic administration and amputation.

Epidermoid Cyst in an Infected Olecranon Bursa

Epidermoid cysts are common, benign cysts that form due to follicular epithelium implanting into the dermis. Although these cysts are often painless, they can incite an inflammatory process as well as abscess formation, especially if ruptured. Our case involves a 59-year-old woman with a history of remote elbow trauma diagnosed with septic olecranon bursitis with concomitant epidermoid cyst found on histology following incision and drainage (I&D). Due to the rare presentation and inadequate preoperative imaging, the diagnosis of epidermoid cyst was not made prior to surgery, resulting in incomplete enucleation.

Giant epidermal cyst of the arm: a rare presentation

A giant epidermal cyst is a benign soft tissue mass commonly involving the trunk, hand and face. The authors report a rare presentation of a 69-year-old man who presented with a painful, slow-growing left arm mass for 30 years duration. Examination revealed a large, mobile, soft tissue mass of the lateral aspect of the left arm. MRI showed a large, cystic left arm soft tissue mass. The mass was excised and the diagnosis of a giant epidermal cyst was made based on imaging and histopathology after surgical resection. The mass measured 9.5 cm x 8 cm x 4 cm, which is the largest reported giant epidermal cyst of the upper extremity.

New reconstruction for bone integration of non-vascularized autogenous bone graft with better bony union and revascularisation

INTRODUCTION

Phalangeal defects are often seen after tumor resection, infections, and in complex open hand fractures. In many cases, reconstruction is difficult and amputation is performed to avoid prolonged rehabilitation that is often associated with a poor outcome. In these cases, the maintenance of length and function presents a reconstructive challenge.

METHODS

We reviewed 11 patients who underwent extensive phalangeal reconstruction with non-vascularized bone graft from the iliac crest using a key-in-slot-joint technique to provide acceptable function and bony union.

RESULTS

In each case, non-vascularized bone graft with a length of 1.4-6.0 cm was used to reconstruct the phalanx. Follow-up ranged from 6 weeks to 5 months, and in all cases, there was bony union after 6 weeks. We evaluated range of motion, function, and as well pain and grip strength of the fingers.

CONCLUSIONS

This case series suggests that a key-in-slot technique allows non-vascularized bone graft to be used in complex large phalangeal bone defects. Due to better bone contact, a sufficient perfusion and revascularisation of the non-vascularized bone graft can be achieved for a quicker and stable bony union. This method appears to be an alternative to amputation in selected cases with a satisfactory soft-tissue envelope.

Intraosseous Epidermal Inclusion Cyst of the Proximal Phalanx of the Fifth Toe and Review of the Literature: A Case Study

Intraosseous epidermal inclusion cysts (IEpC) are benign bone tumors that often present in the phalanges of the fingers, but rarely are seen in the lower extremity. These tumors often present following surgery, and have a similar clinical and radiographic presentation to osteomyelitis. The lack of defining characteristics makes preoperative diagnosis of these tumors very difficult. It is crucial to differentiate these tumors from malignant lesions with similar presentation. This case study presents our treatment of this osseous tumor and reviews the available literature describing this condition.

LEVELS OF EVIDENCE

Level V: Case report.

Intraosseous epidermoid cyst of the distal phalanx reconstructed with synthetic bone graft

Intraosseous epidermoid cysts are exceedingly rare. Known as pseudotumors, not true neoplasms, intraosseous epidermoid cysts usually involve the phalanges, the skull, and the toes. Intraosseous epidermoid cysts typically present as destructive osteolytic lesions on X-ray, mimicking malignant bone tumors. Here, we present two cases of an intraosseous epidermoid cyst in the distal phalanx treated with curettage and synthetic bone graft, followed by a review of the relevant literature. In both cases, the patient presented with a painful enlargement of the fingertip following a minor trauma. Magnetic resonance imaging demonstrated lesions involving the distal phalanx that had a low signal on T1-weighted imaging (WI) and a high intensity on T2-WI. In both cases, the lesions were not enhanced by gadolinium. Good remodeling and functional recoveries were obtained. For physically active patients with substantial bone defects, synthetic bone graft may be recommended.

Primary Tumors of the Foot and Ankle

Tumors of the foot and ankle are rarely encountered in the general patient population. Even among studies of tumor patients, foot and ankle neoplasms are uncommon. Given the weight-bearing demands of the foot and its relatively small area, even small masses are likely to be symptomatic and/or palpable to both patient and physician. Only 3% of osseous neoplasms are found in this region, while 8% of benign soft tissue tumors and 5% of malignant soft tissue tumors are localized to the foot and ankle. Despite the rarity of presentation, it is important for orthopaedic surgeons to be familiar with the diagnostic criteria and therapeutic options for these patients, as each tumor varies in its presentation, level of aggressiveness, and natural history of the disease. With appropriate diagnostic tests and treatment, patients can anticipate a reasonable chance of survival and preservation of function. In this review article, the authors survey the current literature regarding the presentation, diagnostic workup, and treatment for the most common benign and malignant tumors of the foot and ankle.

LEVELS OF EVIDENCE

Level IV: Literature Review.

Giant epidermal cyst of the gluteal region

Epidermal cysts are common, benign, intradermal or subcutaneous, typically asymptomatic masses, ranging from 1 to 4 cm in size. They may occur anywhere in the body, with a predilection for the face, neck, and trunk. Transformation to squamous-cell carcinoma is rare. We present a case of a 61-year-old male patient with a large, growing mass in his posterior left gluteal region. Given the concern for a malignancy, he was referred to a surgical oncologist. Magnetic resonance imaging (MRI) without contrast was performed due to poor renal function and revealed a large cystic mass in the left gluteal subcutaneous soft tissues that was subsequently excised. Pathological examination revealed an epidermal inclusion cyst that measured 17.8 × 13.18 × 5.8 cm. To our knowledge, this is the largest epidermal inclusion cyst reported in the English literature.

An intraosseous epidermal cyst developing in a metacarpal bone after K-wire fixation: a case report

Intraosseous epidermal cysts (IECs) are rare benign lesions caused by the proliferation of epidermal cells within the bone. The pathogenesis of IEC remains unclear; however, trauma-triggered infiltration of the bone by epidermal elements has been suggested. Here, we present a case of an IEC in the metacarpal bone of the little finger associated with K-wire fixation for treatment of a fifth metacarpal fracture.

Sonographic diagnosis of subungual intraosseous epidermoid cyst

Intraosseous epidermoid cyst is an uncommon subungual mass. We report the sonographic findings in a case of intraosseous epidermoid cyst, which showed the characteristic whorled pattern of layers, previously described in other locations and unequivocally clinched the diagnosis in favor of this benign etiology and guided the management to phalangeal-sparing surgery.

Epidermoid cyst of the phalanx of the finger caused by nail biting

Intraosseous epidermoid inclusion cysts of the phalanx of the finger are rare, and are regarded as reactive or post-traumatic pseudotumours. We describe a case of an epidermoid cyst in the distal phalanx of the fifth finger caused by chronic nail biting, which was successfully excised.

Intraosseous epidermoid cysts of the hand skeleton: a series of eight patients

This paper reviews the clinical and radiographic features and treatment results in eight patients with intraosseous epidermoid cysts in the terminal phalanx of a finger seen over a period of 26 years. Data on age, sex, occupation, diagnostic findings, history of injury in six cases, treatment and follow-up were obtained by reviewing medical records and the histopathological findings using the hospital database. The most frequent symptoms of pressure pain, tenderness, redness and swelling occurred at a median time of 12 years after trauma. Male patients were mainly affected (7:1). In four the intraosseous epidermoid cysts were confused with other osteolytic diseases before surgery. Magnetic resonance imaging is recommended in any case of an osteolytic, expanding lesion, particularly in cases that are clinically and radiologically not obviously an intraosseous epidermoid cyst.

Subungual tumors: clinicopathologic correlation with US and MR imaging findings

Various types of tumors can affect the subungual space, including benign solid tumors (glomus tumor, subungual exostosis, soft-tissue chondroma, keratoacanthoma, hemangioma, lobular capillary hemangioma), benign cystic lesions (epidermal and mucoid cysts), and malignant tumors (squamous cell carcinoma, malignant melanoma). Imaging plays an important role in the detection and differentiation of subungual tumors because of their small size, nonspecific clinical manifestations, and functional significance. Ultrasonography (US)-in particular, high-resolution US with color Doppler studies-provides useful information regarding tumor size, location, shape, and internal characteristics (cystic, solid, or mixed), but it is limited in the further characterization of tissue. Magnetic resonance (MR) imaging has an important role in categorizing tumors according to their anatomic location, pathologic origin, and signal characteristics. There is some overlap between the US and MR imaging features of subungual tumors; however, certain features can allow accurate diagnosis and expedite management when correlated with clinical and pathologic findings.

Digital intraosseous epidermoid inclusion cyst of the distal phalanx

Epidermoid inclusion cysts (EIC) of the bone are exceedingly rare. We present a case of an atypical EIC originating at the base of the distal phalanx of the index finger following a remote history of crush injury to the finger. The differential diagnosis of expansile, lytic lesions of the phalanges remains broad, and definitive diagnosis requires tissue histopathological analysis. At latest follow-up, the patient was pain-free and obtained an excellent clinical and radiographic outcome following intra-lesional curettage and bone grafting. Differentiation of EIC from other radiolucent digital lesions remains challenging, especially when classic radiographic findings are not seen. We review the clinical, radiographic, and pathologic diagnostic features of this lesion, as well as our current treatment algorithm.

Intraosseous epidermoid inclusion cyst presenting as a paronychia of the hallux

Intraosseous epidermoid inclusion cysts are rare benign bone lesions that occur most commonly in the skull and in the distal phalanges of the fingers. Herein we report a case of an intraosseous epidermoid inclusion cyst occurring in the distal phalanx of the left hallux. Only six occurrences of this lesion have been described in the foot. This patient's presentation, with active drainage (initially appearing as purulent discharge from an acutely tender ingrown hallux nail) and a known inoculation event accompanied by severe peripheral vascular disease, make this case unique.

Diagnostic exercise: intraosseous epidermoid cysts in the third phalanx of a dressage mare

An 11-yr-old Dressage mare had abnormal gait, and an abscess of the left hoof was suspected but not observed. Radiographic and computerized tomographic evaluations showed a large cystic lesion near the apex of the pedal bone, and a smaller, similar lesion at the lateral wing. Sagittal sections through the affected member revealed two intraosseous cysts at the third phalanx. Histologic and histochemical results characterized the lesions as intraosseous epidermoid cysts of the third phalanx.