Incidence and morphologic characteristics of benign calcaneal cystic lesions on MRI

BACKGROUND: Since we have frequently noted osseous cyst-like lesions within the calcaneus on MRI studies, we sought to systematically evaluate this finding to determine the incidence and morphologic characteristics on MRI. METHODS: Three observers blinded to age evaluated 198 MRIs of the ankle (74 males, 124 females; mean age 47 years, range 13 to 99 years), recording the presence and size of calcaneal cyst-like foci. Statistical analysis was performed to determine if there was an association with age. Additionally, MRI of 12 ankles precontrast and postcontrast were reviewed for the presence of blood vessels in the calcaneus corresponding to the location of the cyst-like lesions and 24 ankle MR arthrograms were reviewed to evaluate communication of the cyst with the adjacent joint. RESULTS: Of the 198 ankle MRI examinations, 81 (40%) had hyperintense foci, all within the mid-calcaneal body. The size ranged from 0.01 cm(2) to 2.47 cm(2), with a mean size of 0.36 cm(2) (+/- 0.45 cm(2)). Thirty-seven (46%) were linear or elongated, whereas 44 (54%) were ovoid or round. Seven of the 81 foci (8.6% or 3.5% of the total population) were 1 cm(2) or larger. There was no significant association of patient age and presence (p = 0.49) or size (p = 0.48) of the focus. Location of the cyst-like foci, which often are ovoid or linear, corresponds to penetrating microvessels on precontrast and postcontrast MRI. One MR arthrogram showed communication of a cyst-like focus and the subtalar joint. CONCLUSIONS: Calcaneal lesions are relatively common incidental findings on MRI. These lesions appear to represent intraosseous ganglion cysts that arise from the anterior margin of the posterior facet of the subtalar joint in the anatomical neighborhood where vessels penetrate the superior calcaneal cortex. The lesions can vary is size; however, there is no correlation between patient age and lesion size and no significant association between age and presence of these foci.     

Epidermoid Cyst Mimicry: Report of Seven Cases and Review of the Literature

Cysts are entities encountered frequently in dermatological clinics. Various types of cysts have been described and include trichilemmal cysts, epidermoid cysts, steatocystomas, and the myriad of developmental cysts (branchial cleft cyst, thyroglossal duct cysts, bronchogenic cysts). Moreover, not all lesions that appear clinically as cystic structures are, in fact, cysts. Increased awareness of these mimickers and a systematic approach to the evaluation of these cases is essential. The authors report seven cases, over the course of six years, presenting to their dermatology department, all of which were originally clinically diagnosed as “cysts” and referred to the authors for management. In this article, the authors review seven cyst mimickers and describe important aspects of these diagnoses to increase awareness of the importance of a preoperative biopsy and evaluation. It is important to have a thorough understanding of the wide differential diagnosis of cutaneous nodules and to consider other causes of lesions that appear to be cysts, particularly in the anatomical locations described.Cysts and cyst-like structures are frequently seen in dermatological practices. Histologically, a true cyst contains a closed cavity surrounded by a wall of true epidermis. The cyst cavity is filled with keratinaceous or fatty material arranged in layers.¹ In contrast, cyst-like structures, although lacking these histological markers, may be clinically identical to true cysts because of similar anatomical location and morphological appearance. It is important to differentiate between these cysts mimickers because true cysts are usually treated by simple surgical excision; whereas, other cyst-like masses may require further diagnostic workup and a more aggressive surgical approach.²It is necessary to have a clear understanding of the various cyst mimickers and to consider these entities when encountering patients with cutaneous nodules.Over the past six years, many interesting cases initially diagnosed as epidermal inclusion cysts were referred for excision to the authors’ dermatology clinic. Many had clinically changed in morphology, size, or color by the time they reached the authors’ clinic, while others remained benign-appearing. These patients were referred to the authors’ department for evaluation of a suspected cyst. This article presents seven cases of cyst mimickers: hidradenoma, cutaneous B-cell lymphoma, epithelioid sarcoma, Merkel cell carcinoma, metastatic adenocarcinoma of the lung, granular cell tumor, and cutaneous meningioma to increase awareness that other lesions can mimic cysts.     

Double synovial cyst of the proximal tibiofibular joint confirmed by MRI as a cause of the peroneal tunnel syndrome

The aim of this case report is to present an unusual double synovial cyst that arose from the proximal tibiofibular joint compressing the peroneal nerve in the peroneal tunnel and was unrecognized at the beginning. According to the review of literature back to 1891, only 62 cases of cysts originating from the proximal tibiofibular joint (PTFJ) have been described. We report a case of a 32 year old male patient who was admitted to the Department of Orthopaedic Surgery because of a classic peroneal tunnel syndrome of the left leg. On the lateral side of the proximal third of his left leg a tumefaction of 12 x 2.5 cm was visible. The sonography showed a characteristic image of the para-articular synovial cyst of the left knee. A surgical extirpation of the synovial cyst and decompression of the peroneal nerve in the peroneal tunnel were performed. PHD confirmed a classic synovial cyst. Postoperatively, the symptoms of the peroneal nerve compression disappeared. Three years after the first surgical intervention the patient was readmitted to the Department because of quite similar problems, only the neurological symptoms were less intensive than during the first admittance. This time the performed MR imaging showed a double synovial cyst originating from the proximal tibiofibular joint. The surgical treatment consisted of a total extirpation of both cysts including the narrow stalks of communication with the PTFJ. The joint was opened and a synovectomy was done using an electrocauter and a sharp curette. Regular check-ups were done every 6 months and twice during the control period of 4 years, as was the MR imaging control. MRI findings 4 years after the second surgical intervention were normal. Clinical findings after 7 years were normal and we are sure that the recidivation of the synovial cyst excluded. The MRI diagnostics was crucial for an adequate surgical treatment and the relief of the peroneal tunnel syndrome symptoms.     

Lipoma arborescens occurring in both knees at different times: a case report

Lipoma arborescens is a rare intraarticular lesion, mainly affecting the knee. A fourteen-year-old girl presented with a slow-growing painless mass in the right knee, of a six-year history. There were no limitations in the movements of the knee. Magnetic resonance imaging (MRI) revealed multiple lesions showing villous lipomatous proliferation of the synovium in the supra- and retropatellar regions and effusion in the knee joint. The mass was excised with arthrotomy and synovectomy and a histopathologic diagnosis of lipoma arborescens was made. Two years postoperatively, and when the right knee was completely asymptomatic, she developed a similar mass in the suprapatellar region of the left knee. An MRI scan showed a mass lesion in the supra- and retropatellar regions, effusion in the knee joint, and a synovial cyst in the popliteal fossa. Again, arthrotomy and synovectomy were performed and the histopathologic diagnosis was lipoma arborescens. This case differs from simultaneously involved knees in that lipoma arborescens in the contralateral knee developed two years after the initial operation.     

Intramuscular dissection of a large ganglion cyst into the gastrocnemius muscle

Ganglion cysts are lesions resulting from the myxoid degeneration of the connective tissue associated with joint capsules and tendon sheaths. Most common around the wrist joint, ganglion cysts may be found elsewhere in the body, including in and around the knee joint. Uncommonly, ganglion cysts can present intramuscularly. Previous reports document the existence of intramuscular ganglia, often without histologic confirmation. This article describes a case of an intramuscular ganglion cyst in the medial gastrocnemius muscle of a 53-year-old woman. The patient initially presented for discomfort associated with the lesion. Examination was consistent with intramuscular cystic lesion of unknown etiology. Ultrasound and magnetic resonance imaging revealed the origin of the mass at the semimembranosus-gastrocnemius bursa. Because of its location, the mass was initially suspected to be a dissecting Baker's cyst, an uncommon but previously reported diagnosis. The patient underwent surgical excision, and examination of the intact specimen revealed a thin, fibrous, walled cyst with no lining epithelium, which was consistent with a ganglion cyst. To the authors' knowledge, this is the first report in the orthopedic literature of a ganglion cyst dissecting into the gastrocnemius muscle. Because ganglion cysts commonly require excision for definitive treatment and do not respond well to treatment measures implemented for Baker's cysts, including resection of underlying meniscal tears, the authors believe it is important for orthopedic surgeons to be able to distinguish between Baker's and other cysts associated with the knee joint, including ganglion cysts, which may require more definitive treatment.     

Devastating complications from alcohol cauterization of recurrent Rathke cleft cyst. Case report

Rathke cleft cysts are commonly found on autopsy but are seldom symptomatic. Conventional treatment of these lesions consists of transsphenoidal drainage with partial excision of the cyst, and recurrence is rare. Alternatively, the instillation of absolute alcohol into the cyst has been described in several reports, with no complications. The authors report on a woman with Rathke cleft cyst that recurred three times after the initial treatment; the lesion was treated with alcohol cauterization on the final recurrence with devastating complications. This 51-year-old woman presented in 1992 with headaches and visual disturbances. Admission magnetic resonance imaging revealed a sellar/suprasellar lesion that was treated with conventional surgery and was subsequently confirmed to be a Rathke cleft cyst. The patient again presented with recurrence of the cyst at 22, 26, and 31 months after the initial presentation. On the final recurrence the cyst was treated with alcohol cauterization. Postoperatively, the patient awoke blind and suffered a seizure from leakage of the alcohol. The patient remains completely blind in both eyes and is also anosmic and has left lid ptosis and exotropia, which signify damage to the first through third cranial nerves. Rathke cleft cysts have been known to recur after primary surgery; however, this is the first report of a single cyst recurring three times despite conventional surgical treatment. Additionally, this is the first report in which devastating complications from alcohol cauterization of the cyst have been described. The authors therefore advocate caution when attempting alcohol cauterization and advise that meticulous care be taken to ensure the patency of the cyst.     

Pituitary adenoma and concomitant Rathke’s cleft cyst

Summary Although pituitary adenomas and Rathke’s cleft cysts have a shared ancestry, they rarely occur simultaneously. Only 32 reports involving a pituitary adenoma and a concomitant Rathke’s cleft cyst were identified upon review of the literature. Most initial presenting complaints include hormonal symptoms, visual disturbances, and headache. Next to growth hormone, Prolactin was the most commonly hypersecreted pituitary hormone. Rathke’s cleft cysts show variable position, size, and signal intensity on magnetic resonance imaging (MRI). Here, we report a patient with a growth hormone- secreting pituitary adenoma associated with a Rathke’s cleft cyst. The mass contained two different signal intensities on MRI. The lesion was successfully removed assisted by intraoperative MRI, when the presence of both lesions was confirmed. When a non-enhancing cyst-like structure is demonstrated on imaging in a patient with a pituitary adenoma, the possibility of a coexisting Rathke’s cleft cyst should be considered.     

The SLAP lesion as a reason for glenolabral cysts: a report of five cases and review of the literature

Introduction: Cysts in the spinoglenoidal or supraglenoidal incisura can be a cause of compression of the suprascapular nerve. There is agglomerated appearance of these cysts in combination with SLAP lesions. Hypothesis is SLAP lesions can lead to cysts in this region and should be repaired. Material and methods: MRI of five patients (all male, four 30–40 years, one 75 years) showed cysts in the supralabral region. All were in combination with lesions of the superior glenoidal labrum (Type II or more). Results: In two cases, in addition to cyst resection, the SLAP lesion was also repaired and symptoms disappeared completely and no recurrent cyst was detected in postoperative MRI. Two patients without SLAP repair showed recurrent cystic formation in MRI with similar complaints compared to their preoperative status. One patient (75 years) was treated primarily by puncture and afterwards with open resection of the cyst. His outcome was good in terms of activities of daily living without major pain. Conclusions: Our results are based on the assumption that cysts in the region of the spinoglenoidal/supraglenoidal incisura can originate from SLAP lesions. If a patient is suspected of having cysts in this region, the question of a SLAP lesion should be clarified. SLAP lesions should be repaired to avoid relapse. Arthroscopic repair of SLAP lesion can lead to the disappearance of symptoms in younger patients. In older patients puncture or resection of the ganglion alone may be an adequate therapeutic strategy.     

Popliteal cysts (Baker's cysts) in adults. I. Clinical and roentgenological results of operative excision

Forty patients were re-examined between 6 months and 15 years (mean 4 years) after excision of a popliteal cyst. Forty-six operations had been performed, including one bilateral cyst and five recurrent cysts. The history was reviewed with respect to the preoperative symptoms, clinical and roentgenological signs, the operative and histopathological findings and the postoperative course. Fifteen operations were followed by wound healing complications or tense swelling of the calf simulating deep venous thrombosis. At clinical follow-up a reccurent cyst was found in 63 per cent of the knees. A simplified follow-up arthrography was performed in all knees, and revealed a cyst-like cavity in all but one knee. The majority of the recurrent cysts displayed irregularities of the wall that had not been seen in the preoperative arthrograms. Despite this high rate of recurrence most of the patients had fewer symptoms from the popliteal space at the time of follow-up than before the operation. as associated knee disorders were present in the majority of patients, popliteal cysts (Baker's cysts) should be regarded and, if possible, treated as secondary to the basic pathological condition of the joint. Only if the knee disorder is not curable and if the symptoms from the popliteal region are troublesome should excision of the cyst and tight closure of the communication with the joint be considered.     

Gigantic popliteal synovial cyst caused by wear particles after total knee arthroplasty

We present a case exhibiting persistent joint effusion and formation of a gigantic popliteal synovial cyst 8 years after total knee joint arthroplasty. Assessment using flow cytometry revealed that both joint and cyst fluid contained abundant macrophage-phagocytosing wear particles. This finding indicates that wear particles participated in formation of the cyst through the communication between the joint cavity and cyst. Intraoperatively, prominent villous synovial proliferation was observed in both the joint and cyst, and delamination failure of the polyethylene insert was identified. Because no evidence of prosthetic loosening was found, only polyethylene insert revision and synovectomy were undertaken, resulting in a successful outcome. This case suggests that synovial cyst formation in popliteal lesions might represent a sign of wear-particle generation after total knee joint arthroplasty.     

Ganglion cyst of the temporomandibular joint with intracranial extension in a patient presenting with seventh cranial nerve palsy

Ganglion cysts arising from the temporomandibular joint are rare entities that often present with swelling and minimal to no pain in the preauricular region. To the authors' knowledge, a temporomandibular joint ganglion cyst occurring with acute facial nerve palsy and intracranial extension has never been reported. The patient in the current case initially underwent treatment for Bell palsy and then draining of the cyst at an outside hospital with no relief of symptoms. Repeat MR imaging showed an increase in the size of the cystic, enhancing, middle fossa lesion measuring 4 cm. Resection of the lesion was undertaken using a middle fossa approach. After a satisfactory surgical decompression, the patient demonstrated a significant recovery in her facial palsy over a 3-month period of time. This case presents new clinical and radiographic findings associated with these lesions.     

Concurrent cysts of the mediastinum, pleura and neck.

A 14-year-old male was found to have a mediastinal mass on chest radiograph. Chest computed tomography scans showed a cystic lesion behind the left main bronchus. Magnetic resonance imaging revealed additional cystic lesions in the left chest and root of the neck. He underwent excision of mediastinal mass and a pleural cyst. The neck lesion was presumed to be a cystic hygroma. Histological examination of the two lesions resected showed them to be a foregut cyst and a benign mesothelial cyst. We know of no other report of concurrent multicystic lesions in the chest and neck and hypothesize that these cysts may have a common embryonic origin.     

Hyperfunctioning parathyroid cysts: a case report

Parathyroid cysts are infrequent lesions of which most are non-functional. They are often misdiagnosed as thyroid cysts. Pre-operative diagnosis and differentiation from thyroid cysts is generally difficult. We hereby report a case that was admitted to the emergency room and was diagnosed as hypercalcemic crisis. The mass found during the neck examination was thought to be a thyroid nodule. A right total and left subtotal thyroidectomy was performed. Palpable thyroid nodule was diagnosed as cystic parathyroid adenoma postoperatively. When a cystic lesion is found in the neck of a patient, a pararthyroid cyst should be considered.     

Solid Aneurysmal Bone Cyst of the Metacarpal Bone

Background: A solid aneurysmal bone cyst is a rare tumor-like lesion of bone. As conventional aneurysmal bone cyst it is a benign, although locally destructive lesion. While the aneurysmal bone cyst is characterized by cyst-like walls of predominantly fibrous tissue filled with free-floating blood, the solid variant shows essential findings identical to those seen in the walls of conventional aneurysmal bone cysts, except that the lesion almost completely lacks the blood-filled spaces and the cyst walls. Differential Diagnosis: Aneurysmal bone cysts and solid aneurysmal bone cysts may easily be mistaken for a malignant tumor, both radiologically and histologically, due to their great rate of growth, tremendous destruction of bone, and marked cellular exuberance in the early to mid phase of development. Case Study: A case of solid aneurysmal bone cyst of the fourth metacarpal is presented. In spite of the relatively unusual location it allows to clearly demonstrate both, the task of correct differential diagnosis and the surgical spectrum of therapy including local recurrence.     

Diagnosing aneurysmal and unicameral bone cysts with magnetic resonance imaging

The differential between aneurysmal bone cysts and unicameral bone cysts usually is clear clinically and radiographically. Occasionally there are cases in which the diagnosis is not clear. Because natural history and treatment are different, the ability to distinguish between these two entities before surgery is important. The authors reviewed, in a blinded fashion, the preoperative magnetic resonance images to investigate criteria that could be used to differentiate between the two lesions. All patients had operative or pathologic confirmation of an aneurysmal bone cyst or unicameral bone cyst. The authors analyzed the preoperative magnetic resonance images of 14 patients with diagnostically difficult bone cysts (eight children with unicameral bone cysts and six children with aneurysmal bone cysts) and correlated these findings with diagnosis after biopsy or cyst aspiration and contrast injection. The presence of a double density fluid level within the lesion strongly indicated that the lesion was an aneurysmal bone cyst, rather than a unicameral bone cyst. Other criteria that suggested the lesion was an aneurysmal bone cyst were the presence of septations within the lesion and signal characteristics of low intensity on T1 images and high intensity on T2 images. The authors identified a way of helping to differentiate between aneurysmal bone cysts and unicameral bone cysts on magnetic resonance images. Double density fluid level, septation, and low signal on T1 images and high signal on T2 images strongly suggest the bone cyst in question is an aneurysmal bone cyst, rather than a unicameral bone cyst. This may be helpful before surgery for the child who has a cystic lesion for which radiographic features do not allow a clear differentiation of unicameral bone cyst from aneurysmal bone cyst.     

Popliteal Cysts (Baker's Cysts) in Adults: I. Clinical and Roentgenological Results of Operative Excision

Forty patients were re-examined between 6 months and 15 years (mean 4 years) after excision of a popliteal cyst. Forty-six operations had been performed, including one bilateral cyst and five recurrent cysts. The history was reviewed with respect to the preoperative symptoms, clinical and roentgenological signs, the operative and histopathological findings and the postoperative course. Fifteen operations were followed by wound healing complications or tense swelling of the calf simulating deep venous thrombosis. At clinical follow-up a recurrent cyst was found in 63 per cent of the knees. A simplified follow-up arthrography was performed in all knees, and revealed a cyst-like cavity in all but one knee. The majority of the recurrent cysts displayed irregularities of the wall that had not been seen in the preoperative arthrograms.

Despite this high rate of recurrence most of the patients had fewer symptoms from the popliteal space at the time of follow-up than before the operation.

As associated knee disorders were present in the majority of patients, popliteal cysts (Baker's cysts) should be regarded and, if possible, treated as secondary to the basic pathological condition of the joint. Only if the knee disorder is not curable and if the symptoms from the popliteal region are troublesome should excision of the cyst and tight closure of the communication with the joint be considered.     

Hyperfunctioning Parathyroid Cysts: a Case Report

Parathyroid cysts are infrequent lesions of which most are non-functional. They are often misdiagnosed as thyroid cysts. Pre-operative diagnosis and differentiation from thyroid cysts is generally difficult. We hereby report a case that was admitted to the emergency room and was diagnosed as hypercalcemic crisis. The mass found during the neck examination was thought to be a thyroid nodule. A right total and left subtotal thyroidectomy was performed. Palpable thyroid nodule was diagnosed as cystic parathyroid adenoma postoperatively. When a cystic lesion is found in the neck of a patient, a pararthyroid cyst should be considered.     

Mucin secreting cystic lesions of the pancreas: treatment by enucleation

Ninety per cent of pancreatic cysts are inflammatory pseudocysts. The other 10 per cent are congenital or neoplastic and include congenital true cysts, retention cysts, lymphoepithelial cysts, the mucinous cystadenoma, mucinous cystadenocarcinoma, and serous microcystic cystadenomas and the more recently described intraductal papillary mucin-secreting neoplasms. The advent of computerized tomographic scanning, endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasonography (EUS) has brought many of these lesions to light when they are minimally symptomatic or are incidentally found while investigating unrelated problems. If there is any suspicion of actual or potentially malignant disease, then total excision of the lesion with part of or the entire pancreas is indicated to achieve a likely cure, as survival is better than for the more common ductal adenocarcinomas. There are few reliable preoperative studies to distinguish accurately the etiology and prognosis of this spectrum of cystic lesions, and usually the actual diagnosis is made only at the time of operation or histopathologic examination after the cystic lesion has been biopsied or excised. If a cyst is confirmed to be totally benign, as in the congenital true cyst, lymphoepithelial cyst, or a benign mucinous cyst, they may lend themselves to nonoperative observation or excision without sacrifice of pancreatic parenchyma. However, many mucin-producing cystic lesions may evolve into a dysplastic or invasive malignant lesion requiring more aggressive resective treatment, and it is important not to miss that diagnosis early when cure is still possible. This report presents four benign mucin-secreting cysts treated by local excision. All four were in the head of the pancreas and communicated with the main pancreatic duct and lacked ovarian-type stroma, thus categorizing them as side-branch intraductal papillary mucinous neoplasms. These lesions were able to be easily dissected out of the pancreas with only one patient developing a transient pancreatic fistula. Intraoperative and final histopathology confirmed the benign status, and these patients have remained disease free 3 to 5 years postoperatively. A review of benign tumors reported to have been treated by cyst enucleation in the literature confirms the rationale of this approach in highly selected lesions.     

Isolated tuberculosis of the popliteal cyst

We encountered a case of tuberculosis of a popliteal cyst in a 76-year-old man. He visited our department for treatment of the left knee pain which had not responded to treatment over the previous ten months. At first examination, local rubor, swelling and tenderness on a popliteal cyst were noted. Therefore, curettage of the lesion, including resection of the cyst, was performed. Six weeks later, an abscess had formed in the subcutaneous area over the lateral aspect of the knee, which was cleaned out. The abscess recurred in the same area four months later. At the third operation, curettage of the abscess together with a knee joint synovectomy was performed. Upon pathologic examination, a tuberculous lesion of the popliteal cyst and skin were recognised. However, no tuberculous lesion was detected in the synovia of the knee joint. It is generally agreed that it is possible for a popliteal cyst to be infected from synovial tuberculosis of the knee joint. However, in our case, based on the histopathological and clinical observations, the primary tuberculous lesion appeared to have been in the popliteal cyst, which is very rare indeed. Recent developments in preventative medicine and chemotherapy have markedly reduced the incidence of tuberculous arthritis. However tuberculous arthritis is still an important disease in the differential diagnostic of persistent monoarthritis of the knee. Approximately half of the popliteal cyst communicate with the knee joint. However, it is not frequent for tuberculosis to propagate from the knee joint into the popliteal cyst.(ABSTRACT TRUNCATED AT 250 WORDS)     

Symptomatic lumbar intraspinal synovial cyst: a case report

Synovial and ganglion cysts, also known as juxta-facet cysts, are intraspinal lesions that may mimic disc herniations and cause radicular symptoms. A 75-year-old male patient presented with a 6-month history of left leg pain and numbness in the foot that increased in severity within the past week. Physical examination showed motor deficit of the left extensor hallucis longus muscle (4/5) and hypoesthesia on the left L4-5 dermatomes. Magnetic resonance imaging revealed an intraspinal cyst originating from the L4-5 facet joint. Medial facetectomy and cyst excision were performed, which provided immediate relief of pain. He had no loss of strength of the extensor hallucis longus muscle and his neurologic examination was normal during the first postoperative year.