Cystic Hygroma in a Dental Hygienist Reporting With Carpal Tunnel Syndrome: A Case Report

Abstract

Objective

This purpose of this case report is to describe the chiropractic management of a patient who presented with symptoms of hand neuropathy.

Clinical Features

A 35-year-old woman presented with a 6-month history of numbness and tingling in the first and second digits of the right hand. Visual inspection revealed a large golf ball-like mass in the patient's right lower neck region. Orthopedic assessment revealed a Tinel's sign at the right carpal tunnel, positive Allen's maneuver, present flick sign, and diminished right radial pulse strength. Advanced diagnostic imaging had been taken previously at the ages of 11 and 24 years, and showed the presence of cystic hygroma in the patient's right axilla and lower neck region.

Intervention and Outcome

The patient was treated using manipulative therapy to the thoracic spine, myofascial release therapy, and therapeutic ultrasound over the right carpal tunnel. Active home care included postural relief exercises and education about work-related ergonomics. Several functional and subjective improvements were seen within the first 2 weeks of treatment. Symptoms of right-hand numbness resolved after 8 treatments.

Conclusion

In this case, the chiropractor originally thought the patient's hand numbness was due to a cystic hygroma; however, this was later considered an incidental finding. The patient's symptoms seemed to respond to chiropractic management and reduced within 1 month.

Introduction

Cystic hygroma is a benign congenital malformation that is a result of abnormal development of the lymphatic and venous systems during fetal development.¹ Approximately 80% to 90% of these tumors occur in children under 2 years of age. Occurrence in adults is extremely rare, with fewer than 100 cases reported.^2,3 Cystic hygroma most commonly presents as solitary tumors, often thin walled, endothelium lined, multiloculated structures containing fluid.⁴ They may be associated with Turner syndrome, Noonan Syndrome, fetal alcohol syndrome, cardiac anomalies, and fetal hydrops.5, 6, 7 Etiologies suggested for cystic hygroma in adults include environmental factors, genetic predispositions, respiratory tract infections, and local trauma.^2,8 Lesions vary in size from a few millimeters in diameter to more than several centimeters.⁹ They occur predominantly in the neck, particularly in the posterior cervical triangle.⁶ The remaining 20% to 30% occur in the axilla, mediastinum, retroperitoneal region, and pelvis. Differential diagnoses include brachial cleft cyst, lipoma, thyroid mass, lymphadenopathy, hamartoma, hemangioma, and thyroglossal duct cyst.

Lymphatic malformations, like cystic hygroma, that involve the nervous system are uncommon.¹⁰ Cystic hygroma of the neck can involve sections of the brachial plexus through either fascial adhesions or compression. Most involvement, however, is with noncritical cervical sensory nerves. For example, restoration of hand sensation can be accomplished through nerve transfers by donating noncritical sensory territories to reinnervate critical sensory territories. Although such cases are apparently rare, the neurosurgeon may consider malformations of the lymphatic system in the differential diagnosis of masses involving the brachial plexus and its branches. Neurosurgeons tend to be the first specialist of choice when dealing with hygroma within the neck, due to the hygroma's intimate nature within the neck anatomy. The management of choice for the majority of cystic hygroma tends to be surgical procedures; therefore, a team of experienced surgeons is necessary for appropriate management.¹¹

Cystic hygromas are considered to be benign lesions that may remain asymptomatic for a long time.¹¹ Even if asymptomatic, treatment is needed when significant pathology within the mass, such as infection or hemorrhage, is evident. Other conditions that could affect a patient's overall well-being, such as respiratory distress and dysphagia, are also indications for treatment. The preferred modality for treating cystic hygroma remains complete surgical excision. Surgical excision of a cystic hygroma, involving deep and vital structures, is considered to be difficult and complex. Some of the unwanted operative conditions include damage to the facial nerve, facial artery, carotid vessels, or internal jugular vessels. Careful postoperative management must be performed in order to avoid complications. These complications include but are not limited to wound infection, hemorrhage, and hypertrophied scar tissue. The recurrence rate after surgical removal is about 20%. There are other treatment procedures that have been performed, with variable success.

As far as we are aware, there are currently no case reports of chiropractic management of symptomatic cystic hygroma. Therefore, the purpose of this case report is to describe the physical-examination and diagnostic-imaging findings in a patient presenting with upper extremity symptoms.

Case Report

History

A 35-year-old woman presented to a chiropractic clinic with a 6-month history of numbness, tingling, and loss of temperature sensation in the first and second digits of her right hand. The onset was sudden, with no known history of trauma or mechanism of injury. The episodes occurred approximately 3 or 4 times per week, and were typically found to be related to the amount of work the patient had done that day: the more hours she worked, the more symptoms she experienced. The patient stated that her symptoms “were not painful as much as bothersome.” She rated her discomfort at a level of 1 out of 10 (0 being no discomfort, 10 being the most discomfort a person could experience). Her numbness was worse during the night, and the flick sign was present for shaking the hand quickly to reduce numbness during sleep.

The patient worked full-time as a dental hygienist, attending to patients for most of the workday. She described how her work frequently involved positions of prolonged cervical flexion. Her hand numbness seemed to intensify after a long shift at work, in which her wrist was in a flexed position, using a small vibratory dental cleaning tool. In addition, she stated that running the affected fingers under warm water helped relieve the numbness and loss of temperature sensation. The numbness or tingling mildly interfered with work-related tasks, but did not interfere with her nonwork activities of daily living.

The patient's medical history revealed a resection of a cystic hygroma from the right axillary region in 1990. Presurgical radiographs from that time show diffuse swelling of the right axillary region. The mass measured approximately 10 cm in diameter (Fig 1A). Presurgical axial computed tomography and sagittal magnetic resonance imaging (MRI) of the axillary cystic hygroma showed a well-defined lesion within the right axilla showing high signal on T2-weighted images, consistent with a lymphatic tumor (Fig 1B and 1C). The mass was surgically removed within 1 year of this imaging, and its morphology and histology were consistent with a cystic hygroma. After the surgical removal, there were no recurrences of the hygroma and no problems associated with the right axilla area.

Fig 1.

Right axillary cystic hygroma, age 11. Initial posterior-anterior radiograph of the chest reveals a large soft tissue mass (asterisk) in the right axillary region (A). Transaxial computed tomography through the upper trunk obtained at the same time as the initial radiograph reveals a hypodense oblong mass (arrows) in the right axilla (B). Coronal T2-weighted spin echo magnetic resonance image reveals that the axillary subcutaneous mass (asterisks) is well circumscribed and encapsulated and has a relatively homogenous fluid-filled matrix (C).

The patient reported a second cystic hygroma currently present in the right anterior-lateral lower neck region (Fig 2). This mass first became evident to the patient in 2002 and was accompanied by mild difficulty swallowing. A T2-weighted MRI revealed an ill-defined soft mass measuring 8 × 5 × 3 cm (Fig 3). Identified through MRI, the lesion was located deep to the right sternocleidomastoid muscle, superficial to the right internal jugular vein, and extending medially to the left of the right common carotid artery. The internal jugular vein and common carotid were displaced anteriorly, but there was no involvement of the esophagus or cervical sympathetic nerves. The patient had seen a neurosurgeon on 2 separate occasions because she was concerned that she might have another growth that might need to be surgically excised. According to her recollection of the visits, the surgeon explained that due to the placement of the hygroma and its relationship to the vasculature in the neck, she would be a good candidate for surgical removal of the mass. The patient opted to not go through with the surgery because she had no health insurance, and she had been attempting to get pregnant and did not want to go through any surgical procedure during that time. The neurosurgeon was aware of the patient's choices and suggested that she see a physical therapist for some stretching and rehabilitation. The patient was referred from a personal friend to the chiropractic clinic. She sought care at the chiropractic clinic within 1 week of her second neurosurgical consultation.

Fig 2.

Clinical photograph showing prominent right-sided supraclavicular soft tissue mass.

Fig 3.

Right supraclavicular cystic hygroma, age 24. Transaxial computed tomography through the supraclavicular region reveals a hypodense horseshoe-shaped soft tissue mass (arrows) posterior to the right clavicle (Clav) and surrounding the common carotid (CC) artery (A). Transaxial T2-weighted fast spin echo magnetic resonance (MR) image at a similar level as (A) shows a bilobed encapsulated subcutaneous mass (asterisks) that is predominantly fluid-filled (B). Coronal T2-weighted spin echo MR image demonstrates that the lobulated mass (asterisk) envelops the sternocleidomastoid muscle (C). Sagittal T2-weighted spin echo MR image reveals a bilobed mass (asterisk) deep to the sternocleidomastoid muscle (D).

Physical Examination

Inspection of posture revealed mild forward head carriage with slight rounded shoulders. A large mass the size of a golf ball (Fig 1A) was seen at the lower right anterior neck area. Upon palpation, the mass was nontender and nonmatted. It was most visibly pronounced when the patient turned her head to the left and looked up into extension. The mass was auscultated, and no bruits were noted. Palpation of the cervical spine and surrounding musculature revealed mild tenderness and hypertonicity of the upper trapezius, and tender points (grade I) within both rhomboid muscles. Mild limitation of active and passive ranges of motion of the cervical spine was identified in lateral flexion bilaterally without the use of inclinometers. Restriction of intersegmental joint play was identified in several areas in the cervical and upper thoracic spine. Allen's maneuver for compression of the brachial neurovascular bundle was positive on the right side, producing a slower radial refill rate compared to the left side. The radial pulse's patency was diminished on the right side, having an amplitude value of 1 out of 4 (a normal amplitude would be rated a 2). This is suggestive that a potential compressive force is decreasing the volume of blood into the right upper extremity. Tinel's sign was present over the right carpal tunnel, producing numbness and tingling into the first 3 digits. The patient stated that this was the exact quality of symptoms that she typically had in her affected hand. Phalen's test, the scapular approximation test, Spurling's A, the costoclavicular test, Adson's test, and the upper limb tension test A all produced negative results, with no other significant findings. Upper extremity motor testing was normal, and the deep tendon reflexes were 2+ bilaterally. At the time of examination, sharp/dull testing elicited no abnormal sensation bilaterally.

Diagnosis

The working diagnosis for the patient's hand complaint was right upper extremity peripheral neuropathy, specifically carpal tunnel syndrome (CTS). The original thought, through history and inspection, was that the cystic hygroma was causing compression of the brachial plexus and thereby the symptoms of hand numbness. However, the examination demonstrated that the symptoms were being produced at the wrist and elbow areas only.

Management

Conservative management consisted of diversified chiropractic manipulative therapy to the restricted segments of the thoracic spine. The patient had several areas of hypomobility in the T4/T5 area. Owing to the location of the cystic hygroma and its close proximity to, and displacement of, the internal jugular vein and common carotid artery, cervical spine manipulative therapy was not performed. Therapeutic ultrasound (2.5 W/cm², 3.3 MHz, 20%, pulsed for 8 minutes) was applied to the transverse carpal ligament of the affected side. In addition, carpal and metacarpal mobilization techniques were performed to address the CTS. Specifically, the latter technique involved a palmar-to-dorsal and dorsal-to-palmar shearing mobilization of the proximal and distal rows of the carpal bones. In an attempt to provide generalized muscle relaxation, myofascial release was administered to the upper trapezius, pectoralis minor, rhomboid, abductor pollicis, and palmar interossei muscles for approximately 5 minutes on each visit. The active exercises prescribed consisted of stretching for postural relief 3 times per day. Specifically, this required the patient to sit straight, create neutral axial retraction of the cervical spine, externally rotate the shoulder, and attempt to bring her elbows towards her back pockets. Information to improve workplace ergonomics was also provided, to address the overuse of forearm flexors.

The patient received a total of 8 treatment sessions. After 4 sessions, the frequency of episodes of numbness and tingling in the first 2 digits of the right hand decreased from 3 or 4 times per week to once per week. A reevaluation was performed after 8 treatments, and the patient's once-positive orthopedic tests were negative. She also reported no upper extremity neuropathy symptoms. During this time the patient reported that she consistently performed her daily stretches at home. The patient gave consent to have this information published.

Discussion

Our search on PubMed demonstrated only 1 article specifically relating to management of upper extremity neuropathy due to cystic hygroma, and no chiropractic literature describing patients with cystic hygroma. Within the last 5 years, there have been 8 cases of cervical cystic hygroma in adults reported in the literature. The majority of research involving cystic hygroma was done in the late 1990s and early 2000s.

The cystic hygroma was initially thought to be the cause of the patient's hand symptoms, because of its size and position near the brachial plexus. One differential diagnosis, after taking the patient's history, was that the cervical cystic hygroma was acting as a space-occupying lesion in the thoracic outlet, potentially creating a thoracic outlet syndrome. However, after examination, the thoracic outlet syndrome was ruled out, and it was hypothesized that the etiology of the symptoms was compression of the median nerve in the carpal tunnel.¹² The peripheral neuropathy was presumed to be a result of an overuse syndrome of forearm flexors in the patient's occupation as a dental hygienist. It was easy to theorize that a large mass—cystic hygroma—in the lower neck region would be the cause of the patient's upper extremity neuropathy, but this case demonstrates the importance of a full neurologic examination, which proved otherwise.

Carpal tunnel syndrome is 1 of the most common disorders of the upper extremity and the most prevalent compression neuropathy.¹² In CTS, increased pressure in the carpal tunnel compresses the median nerve, leading to numbness, tingling, and pain in the palmar aspect of the first 3 fingers and lateral half of the fourth. There are a variety of symptoms, which can include pain or numbness localized to the hand or wrist and in some cases pain radiating into the forearm or shoulder.¹³ Evidence suggests that occupations requiring the use of hand-operated vibratory tools or repeated forceful movement of the hand and wrist are associated with CTS.¹⁴ The diagnosis of CTS can be made by history, physical examination, and orthopedic testing.^15,16 In this case, the suspicion of CTS was based on the patient's history of use of hand-operated vibratory tools in her job as a full-time dental hygienist, presentation of paresthesia in the first 2 fingers, presence of Tinel's sign at the carpal tunnel, and flick sign during the night. According to the literature, the principal clinical tests for CTS are Phalen's maneuver and Tinel's sign.¹⁶ Tinel's sign at the wrist is performed by tapping on the transverse carpal ligament with a finger or the tip of a tomahawk reflex hammer. A Tinel's sign present at the wrist would reproduce median nerve symptoms into the hand. The patient experienced the same symptoms of her chief complaint when the test was performed. Phalen's maneuver involves flexing the wrist to 90 degrees for 1 minute. This position can create median nerve symptoms within the hand. Although this patient did not have a positive Phalen's maneuver during the physical examination, she was not symptomatic at the time of testing. Sensory findings in CTS also may be exacerbated by 2-point discrimination, vibration, and temperature. One systematic review¹⁶ evaluated the “effectiveness of findings from the history and physical examination in predicting positive nerve conduction studies,” and determined that significant predictive findings were symptom location, hypoalgesia (decreased sensation of sharp/dull testing along the palmar index finger), and weak thumb abduction.

Electrodiagnostic studies can also aid in the diagnosis of CTS. However, it is of clinical importance to note there is some literature suggesting that electrophysiologic diagnosis remains somewhat controversial. In 1 study, a nerve conduction study was performed in approximately 2500 people with median nerve symptoms, and confirmed the presence of median nerve neuropathy in approximately 45% of participants.¹² Moreover, the same testing identified approximately 20% positive median nerve neuropathy in the asymptomatic control group.

Best practices for managing CTS involve conservative care. Conservative care for CTS includes wrist splinting, oral corticosteroid therapy, and local corticosteroid injections.¹⁶ Approximately 80% of patients first respond to this type of care; however, symptoms reoccur in 80% of patients within 1 year. The patient in this case was treated with mobilization to the wrist, thoracic spine manipulation to hypomobile joints, therapeutic ultrasound at the carpal tunnel, active care postural exercises, and patient education. A recent randomized control trial suggests that ultrasound therapy may be beneficial individuals with CTS, showing greater pain improvement at 12 weeks from shockwave therapy, and that long-term follow-up is needed.¹⁷ The patient in this case adhered to the treatment plan. She responded well to both the passive and active care that was given.

Cystic hygromas are typically found in the neck, yet this location appears to minimally create local neurovascular compression or adhesions. Although rare, it is recommended that any patient with cystic hygromas and upper extremity neuropathies be tested for neurogenic syndromes. Conservative care should be considered the first line of therapy even for those with structural abnormalities. More recently, there have been case reports demonstrating the successful use of sclerosant agents. Intralesional bleomycin as a primary treatment modality is 1 of the main sclerosant agents used. Bleomycin is a chemotherapeutic agent used in chemotherapy for a number of malignancies. Although its exact mechanism of action within the cystic hygroma is not known, it is a DNA synthesis inhibitor, which may produce a nonspecific inflammatory process that results in fibrosis of the cyst.

The treatment of a cervical hygroma is not within the scope of practice for a chiropractor, and referral to an eyes-ears-nose-throat physician or neurosurgeon would be the most appropriate course of action. The intimate relationship of hygromas and their anatomic structures must be assessed fully. Cervical spine manipulative therapy might have been performed in this patient if she had not had the cystic hygroma, because she exhibited tenderness in the posterior area of the suboccipital muscles bilaterally, bilaterally mildly limited lateral flexion active range of motion, mild generalized neck pain, and several hypomobile segments of the cervical spine. Ideally, she would benefit from reducing the hypertonicity of the upper trapezius musculature, which may be helpful with increasing the lateral flexion of the cervical spine and decreasing some generalized tenderness along the muscle bellies. The manual therapy of choice to achieve this outcome would have been gentle static stretching. However, due to the remarkable findings in the MRI, the patient's care plan included avoidance of all myofascial soft tissue manual care and manipulation in the cervical spine region. All health care providers should be able to determine the safety of cervical spinal manipulation by identifying preexisting conditions, using advanced imaging reports and labs (if available), and assessing the risk/benefit scenarios.

Cervical cystic hygromas are rare in adults. These masses may cause compressive neuropathies to develop, especially symptomatic within the upper distal extremities. In the clinical setting, the clinician should perform a full neurologic examination of the head and neck and upper extremities. Although the finding of a hygroma was incidental in this particular case, it is important to understand the nature of the pathology and possible management options for patients.

Limitations

Advanced studies, such as electrodiagnostic studies, were not used to confirm the diagnosis of peripheral neuropathy at the right wrist. Therefore, a definitive diagnosis of CTS could not be confirmed. In this case, the CTS diagnosis was made based on history and orthopedic testing, and likely confirmed by a positive response to treatment. Some of the orthopedic tests used for diagnosis have limited sensitivity and specificity. The diagnosis of cystic hygroma was established based on prior history and interpretation of MRI images and radiographs. The gold standard for diagnosing cystic hygroma is histologic examination. Although recent cervical MRI imaging would have been ideal, the patient did not agree to it, because she had no health insurance and the imaging was too costly for her.

Conclusions can only be drawn with respect to this particular case, and may not necessarily be replicated in others. It is unknown if the response to care was simply an improvement due to the normal course of the patient's condition. Watchful waiting may have allowed tissues and structures to heal and symptoms to go away on their own. Since a conservative manual therapy multimodal approach was taken in the management of CTS, the ability to determine the individual efficacy of each component is limited.

Conclusions

In this case, the chiropractor originally thought the patient's hand numbness was due to a hygroma, but that was later considered an incidental finding. The patient responded favorably to chiropractic management, and her symptoms were reduced within 1 month.