Introduction
Up to the first half of 20th century all cystic cervical metastasis of squamous cell carcinoma were thought to be of branchiogenic origin. They were labeled as cancers of branchial cleft cysts, which have undergone malignant degeneration. Now it is known, that certain squamous cell carcinoma of waldeyer’s ring is capable of producing a cystic cervical metastasis. The aim of this case report is to highlight such phenomenon which aids doctors in such diagnostic dilemmas.1, 2, 3 The majority of cystic secondaries arise from oropharyngeal tumors.4
Figure 3
Axialcut section of contrast enhanced computed tomogram showing a hypodense lesionon the right of neck extending up to clavicle with no contrast uptake and withno significant central necrosis.
Case Report
A 57-year-old male presented to our department with a right side slow growing neck swelling for 2 years. The swelling was about 9cmX7 cm in dimension and it extended from below the ear lobule on the right side to two fingers above the clavicle in vertical dimension and horizontally from anterior border of sternocleidomastoid to anterior border of trapezius. On clinical examination it was a solitary swelling with diffuse margins, uniform with non-bosselated surface, skin over the swelling appeared normal [Figure 1]. On palpation the swelling was having normal temperature, non-tender, cystic, fluctuant, but fixed to underlying structures, compressible but not reducible. Skin was pinchable over the swelling. There was no bruit on auscultation and swelling was trans-illuminant [Figure 2]. There was history of smoking and alcohol consumption. There was no history of weight loss or night sweats. No history of hemoptysis and hematemesis.
Rest of ear, nose and throat examination was normal. Ultrasonography revealed a heterogenous, hyperechoic cystic lesion on the right side. FNAC from the right side swelling aspirated 10 ml of straw-colored fluid which neither revealed any malignant cell nor cholesterol crystals. CECT neck revealed a large hypodense lesion on the right side with no contrast uptake [Figure 3]. Since a malignant lesion couldn’t be identified a diagnosis of branchial cleft cyst was made and surgery advised, which the patient refused.
The patient presented after a month with voice change, difficulty in swallowing and another swelling on left side of the neck. The second swelling was about 3cmX2 cm behind the angle of mandible [Figure 4]. It was hard in consistency and fixed. Direct endoscopy revealed right vocal cord paralysis. Rest of the cranial nerve examination were normal. FNAC from the left neck swelling revealed metastatic squamous cell carcinoma. Patient was advised for PET-CT to pick up unknown primary, which revealed a left tongue base lesion [Figure 5 ]. Patient underwent excision biopsy from tongue base and extended radical neck dissection on right side (internal jugular vein thrombosed, sternocleidomastoid, platysma, vagus and hypoglossal nerve involved) and modified radical neck dissection type III on left side.
Discussion
Cystic cervical swelling often presents a diagnostic challenge for an otorhinolaryngologist because these lesions can be either benign or malignant. According to literature, any cervical swelling in an adult above 40 years of age should be considered malignant till proven otherwise 5. Previously, patients with cystic cervical metastasis were considered to be having branchiogenic carcinoma, which occurs due to malignant transformation in vestigial remnants of the branchial pouches.1, 2, 3
The recent literature, lays suggests that a solitary cystic cervical secondary may be associated with an occult or unknown primary in the tonsils, base of tongue or nasopharynx.6 The cystic secondary has a better prognosis, in comparison to solid neck secondaries of squamous cell carcinomas of the head and neck. It carries, 5-year survival rate of 77% and a 10-year survival rate of 50% (4).
The cystic metastatic lymph node has the major volume of liquid center with peripheral solid rim of lymphatic tissue. This occurs due to pseudocystic changes resulting from spontaneous breakdown of keratin and necrotic degradation of carcinomatous deposit.7 It also, may occur due to blockage of lymphatic flow in a metastatic node and collection of lymph.8 The nodal metastases in human papilloma virus associated squamous cell carcinoma of oropharynx, have been found to be prone for cystic degeneration.9 Also, the malignant cells have a slower growth rate in cystic metastasis10, that explains our patient long history of 2 years before presentation.
In an adult patient with cystic cervical mass, there is a possibility of malignancy and the clinical and radiological assessment should include whole head and neck area, in particular tonsils, base of tongue and nasopharynx. Any suspicious looking lesion should be biopsied and submitted for histopathology examination.
FNAC is a routine, simple investigation helpful in solid cervical lesions, but the sensitivity to reach a true diagnosis is low in malignant cystic metastases and branchial cysts (73% and 60% respectively).6 The false negative report in cystic secondary patient, may lead to false security, resulting in delay in search for primary and initiation of appropriate oncologic treatment. The FNAC should be repeated under ultrasound guidance from solid parts in the cyst, when in doubt.
The ultrasonography and Computed Tomography aids in the diagnosis of a cervical cystic mass. The branchial cleft cyst is well circumscribed, oval-shaped, with a non-contrast enhanced thin wall, with a hypodense and homogeneous center and with no septations. While the nodal metastatic lesion will be irregular, with peripheral contrast enhancement, invasion of adjacent structures, internal vascularization, heterogeneous center and internal septations.4 PET- CT, as in our case is helpful to identify unknown primary and also rule out chest metastasis, in patients presenting with secondaries, but negative clinical and radiological work-up.11
Conclusion
Cystic cervical metastatic swelling is uncommon presentation as it mimics branchial cleft anomaly. In an adult over 40 years of age, thorough clinical, Histopathological and radiological examination of head and neck is necessary. As the treatment protocol for benign and malignant pathology is very different, delay in treatment may be life threatening for the patient with malignancy. This case report specifically highlights these points.
