PAPILLARY THYROID CARCINOMA PRESENTING AS A LATERAL NECK MASS MASS Dr. Pamela Hanson DO PGY3
MK CASE PRESENTATION 28 yo Female presented to the ENT Clinic in October 2016, with the complaint of chronic tonsillitis and chronic sore throat. Associated with intermittent swelling of the right neck. Previously seen for similar complaints in 2015 where CT neck performed and Ultrasound guided FNA suggested Type 3 Branchial cleft cyst. PMH, Soc Hx, Medications, Family History were denied as was upon original presentation. Physical Exam: Right non-tender mass palpable lateral to SCM. 2+cryptic hypertrophic tonsils with tonsilliths.
CT SCAN 12/19/15 The right anterior cervical chain contained a 1.6 x1.2 x2.1cm lymph node. All other structures: wnl. Thyroid gland was unremarkable.
ULTRASOUND WITH FNA 2/4/2016 Ultrasound guided FNA of the right neck cyst. Right neck cyst measuring 2.0cm located deep to SCM and posterior to the right internal jugular vein and right common carotid artery. Impression: possibly a type 3 Branchial cleft cyst Pathology result: negative for malignant cells; 30ml of light brown, clear fluid Given normal results, patient was offered Surgical Excision but declined.
FNA 2/4/16 See Lymphocyte with single round nucleus
CT NECK 10/8/2016 Simple fluid density, non enhancing, mass measuring 1.8 x 1.5 x 2.5cm located deep to the right SCM and posterior to the right common carotid artery and right internal jugular vein. No lymphadenopathy Thyroid and salivary glands within normal limits. IMPRESSION: Stable cyst likely representing third branchial cleft cyst
EXCISION OF RIGHT DEEP NECK BRANCHIAL CLEFT CYST WITH TONSILLECTOMY 11/8/2016 Right level III/IV neck dissection demonstrated a 1.5cm pathologic appearing lymph node deep to the right SCM adjacent to the carotid sheath. Labeled right neck mass #1. Deeper dissection of the neck, posterolateral to carotid sheath, demonstrated approximately 2 cm encapsulated dark cystic appearing mass. Labeled right neck mass #2 Both sent to pathology Tonsillectomy demonstrated bilateral hypercryptic tonsils
PATHOLOGY RESULTS Specimen Right neck mass #1: Thyroid papillary Carcinoma. Focal small lymph node with metastatic thyroid papillary cancer Specimen Right neck mass #2: One lymph node with metastatic thyroid carcinoma (0.8cm) Tonsils: chronic tonsillitis with lymphoid hyperplasia
RIGHT NECK CYST psammoma body cyst wall
LYMPH NODE FROM FIRST SURGERY Psammoma bodies
THYROID ULTRASOUND 11/27/2016 The right thyroid is normal size measuring 58 x 16 x21mm. The left thyroid is also normal size measuring 59 x 13 x16mm. There are no masses or cysts identified. *normal thyroid lobe size is 4-6cm in length and 1.3-1.8cm thick
TOTAL THYROIDECTOMY WITH LEVEL 6 NECK DISSECTION Thyroidectomy and sent for pathology small lymph nodes noted in level 6 region and sent for pathologic analysis.
PATHOLOGY FROM THYROIDECTOMY Total thyroidectomy Right lobe measured 5.0 x 2.2 x1.8cm. tumor measuring 3.7mm with Papillary Carcinoma architecture Margins uninvolved by carcinoma Left lobe measured 4.4 x 1.7 x 1.2cm Right paratracheal lymph node one of four nodes positive for metastatic thyroid papillary carcinoma
LOW RESOLUTION Normal tissue tumor
HIGH RESOLUTION See Psammoma body, orphan annie nucluei. See nuclear clearing as well as the chromatin moving to the side. also see crowding
POSITIVE METASTATIC LYMPH NODE
THYROID CANCER MET UPTAKE AND WHOLE BODY SCAN No evidence of metastatic disease. I-131 thyroid uptake value is 1.3%
STAGING. POST OP DIAGNOSIS Patient based on age alone is Stage 2 T1N1M0 Further treatment: post op radiation iodine-performed 1/30/2017 without complications
WHAT THE LITERATURE SAYS Cervical Cyst Lymph Mass as Metastasis is rare. Commonly called Occult Papillary Thyroid Carcinoma (OPTC) [1] First case reported in 1992 after 37 yo female had enlarging cervical neck mass. FNA was normal and was clinically thought to be a branchial cleft cyst. Found a 4x2cm cystic mass on the carotid sheath filled with coffee-ground fluid [3]. Thyroid scan found cold nodule and surgically revealed papillary carcinoma. Occult Papillary Thyroid Carcinomas that originally present as a lateral cervical neck mass have been reported in 30 percent of the cases [3,4], thus making this presentation rare, as approximately 60 cases have been reported [3, 4, 5, 7, 8].
Incidence of ectopic thyroid tissue is about 40% in thyroglossal duct cysts [2] False negative results in FNA of thyroid cystic lesions were in 8% Normal thyroid scans in 80% with thyroid carcinoma [3] Cystic metastases of Papillary Thyroid Carcinoma appears blue-black and contain a chocolate-brown serous fluid whereas branchial cleft cyst usually contain yellow fluid [5]
LATERAL CYSTIC MASS VS. BRANCHIAL CLEFT CYST Controversy exists regarding the distinction of a Branchial Cleft Cyst containing ectopic papillary thyroid carcinoma tissue and metastatic papillary thyroid tissue in a Branchial Cleft Cyst. A lateral neck cyst can be from a primary thyroid metastasis, or from liquid necrosis of the lymph node [1]. Theories regarding the pathophysiology of the Branchial Cleft Cysts with ectopic tissue are mainly due to congenital obliteration of the branchial pouches causing ectopic thyroid tissue to be present within the branchial cleft or the epithelial inclusions are within the cervical lymph node [8]. Another theory is acquired in that the epithelium of the branchial cleft is acquired through the lymphatics from the aerodigestive tract and will cause degeneration of the cervical lymph node leading to a cyst [8].
LATERAL CYSTIC MASS VS. BRANCHIAL CLEFT CYST Papillary Thyroid Carcinoma diagnosis can be achieved by ultrasound where features suggest hyper echoic, ill-defined boundary, punctate calcification and hyper vascular; whereas a Branchial Cleft Cyst demonstrates hypoechoic, well-defined, absent calcification and avascular [1]. A Branchial Cleft Cyst aspirate is an opaque yellow color whereas papillary carcinoma aspirate is a brown or chocolate-brown murky fluid [5, 7]. The current case showed a light brown, clear fluid of the aspirate that on ultrasound showed internal echoes, avascular and no solid component. Nakagawa, et al., add that the presence of intracystic hyper echoes on ultrasound is specific for metastasis of papillary thyroid carcinoma [5]. The cystic wall of the specimen is also important to distinguish between an Occult Papillary Thyroid Carcinoma and a Branchial Cleft Cyst containing ectopic papillary thyroid carcinoma. The lateral cystic neck mass of an Occult Papillary Thyroid Carcinoma demonstrates an atypical cuboidal epithelium to pseudo stratified columnar epithelium; whereas a papillary thyroid carcinoma arising from a Branchial Cleft Cyst demonstrates a single squamous or cuboidal epithelial layer with lymphoid tissue [2,3]. Further criteria for a Papillary Thyroid Carcinoma arising in a Branchial Cleft Cyst notes normal thyroid tissue adjacent to the carcinoma within the wall and no evidence of papillary thyroid carcinoma in the thyroid or other areas [9]. Including this criteria, our case is then defined as an Occult Papillary Thyroid Carcinoma with metastasis presenting as a lateral cystic neck mass.
The current case led to some final questions regarding the pathology cuts of the specimen. Is there a universal standard of cuts in millimeters or centimeters when a pathologist is given a specimen? Per our pathologist, there is no universal written standard but our hospital cuts at 4-5mm slices top to bottom unless given a specimen where the tumor is tagged, or already diagnosed with cancer. So was it by happenstance the specimen in this case was cut to find the tumor? Were the twenty or so cases reported as a Papillary Thyroid Carcinoma arising from a Branchial Cleft Cyst because they did not have a tumor found in the thyroid a pathology error from the specimen cuts?
DISCUSSION Occult Papillary Thyroid Carcinoma must be considered as part of the differential diagnosis in solitary cystic neck mass. The presentation of lateral neck swelling may mimic a Branchial Cleft Cyst and commonly misdiagnosed as such. Many of the primary tumors in the thyroid are mirocalcification in nature and can be smaller than 1mm and commonly missed, thus relying heavily on the cystic fluid of the FNA and cyst epithelial type lining. Aspiration of the cystic fluid that is not the branchial cleft characteristic opaque yellow should warrant a high suspicion of the cyst being non-branchial related. A chocolate-brown aspirate should be suspicious for Occult Papillary Thyroid Carcinoma. A branchial cyst is lined with stratified squamous, cuboidal or respiratory-type epithelium and lymphoid tissue. Occult Papillary Thyroid Carcinoma has a cystic mass lining as cuboidal, psuedostratified columnar or flattened epithelium.
REFERENCES [1] Chang, et al. Occult Papillary Thyroid Carcinoma Initially Presenting as Cervical Cystic Lymph Node Metastasis. Journal of Medical Ultrasound. 2013; 21:92-96. [2] Jadusingh et al. Thyroid papillary carcinoma arising in a Branchial Cleft Cyst. The West Indian Medical Journal. 1996; 45:122-124. [3] Hwang, et al. A long-standing cystic lymph node metastasis from occult thyroid carcinoma. The Journal of Laryngology and Otology. 1992; 106:932-934. [4] Nakagawa, et al. Differential Diagnosis of Lateral Cervical Cyst and Solitary Cytic Lymph Node Metastasis of Occult Thyroid Papillary Carcinoma. The Journal of Laryngology and Otology. 2001. 115:240-242. [5] Monchik, et al. Occult Papillary Carcinoma of the Thyroid Presenting as a Cervical Cyst. Department of Surgery and Pathology, Rhode Island Hospital and Brown University School of Medicine. 2000. 129:429-432. [6] National Institute of Health. https://seer.cancer.gov/statfacts/html/thyro.html [7] McDermott, D., et al. Metastatic papillary thyroid carcinoma presenting as a typical branchial cyst. The Journal of Laryngology and Otology. 1996; 110:490-492. [8] Garcia, Raul, et al. Solitary cystic lymph neck node metastasis of occult thyroid papillary carcinoma. Med Oral Patol Oral Cir Bucal. 2008; 13(12): E796-9. [9] Cho, Jin, et al. Primary papillary carcinoma originated from a Branchial Cleft Cyst. J Korean Surg Soc. 2011; 1:S12-6.