Int

Primary thyroid lymphoma is a rare tumour of the thyroid gland, accounting for 1-2 % of all thyroid malignancies. Diagnosis by fine needle aspiration cytology occasionally inconclusive, needing bigger biopsy or even thyroidectomy. This study reviews our experience with primary thyroid lymphoma.

Primary thyroid lymphoma is a rare disease accounting for 2% of both extranodal lymphoma and thyroid malignancy. It occurs in 5th to 7th decade and mainly in female. The tumour is mainly of Non Hodgkin type lymphoma and commonly associated with autoimmune thyroiditis. The preoperative diagnosis can be difficult with fine needle aspiration cytology ( FNAC ) alone due to difficulty in distinguishing this tumour from a background of Hashimoto thyroiditis. Although detection of immunohistochemistry (CD20 ) was reported to increase yield of accuracy for FNAC result of thyroid lymphoma¹, it was not routinely done in our centre. We present 5 cases of thyroid lymphoma and treatment for each of them

This is a retrospective analysis of cases of primary thyroid lymphoma managed in Department of Surgery HUKM over 2 years from January 2005 till December 2006

A 70 year old lady, presented to our unit with an anterior neck swelling for four years with a sudden increase in size over the previous three months. There was stridor at presentation. There was firm 19 x 17 cm anterior neck swelling. FNAC was suspicious of a malignancy. An emergency subtotal thyroidectomy was performed in view of airway obstruction and later followed by chemotherapy (Rituximab-CHOP) after a diagnosis of lymphoma was made.

A 67 year old male presented with a 1 month history of progressive anterior neck swelling, hoarseness of voice and stridor. FNAC was inconclusive. Emergency subtotal thyroidectomy was performed in view of airway obstruction. R-CHOP chemotherapy regime was later given after histological confirmation.

A 50 year old Malay lady presented with an anterior neck swelling for a month and associated with difficulty in breathing. She collapsed upon arrival and was immediately intubated. A total thyroidectomy was performed to relieve the airway obstruction. Later it was complicated with an oesophago-cutaneous fistula which healed with conservative treatment. She later received R-CHOP regime.

A 43 year old female presented with anterior neck swelling for many years, with a history of sudden increase in size over the one month prior to admission. She also had dysphagia and hoarseness of voice. Clinically, there was a huge neck swelling with multiple cervical lymphadenopathy. FNAC was suspicious of a malignancy and a tru-cut biopsy confirmed B cell non Hodgkin lymphoma. She was then given R-CHOP regime

A 70 year old Malay lady presented with a sudden increase in thyroid swelling after more than 10 years history of anterior neck swelling. She had difficulty in breathing but was able to talk in complete sentence. Clinically she was euthyroid and not tachypnoeic or dyspnoeic. Her thyroid FNAC was suspicious of a malignancy. A tru-cut biopsy confirmed a diagnosis of thyroid lymphoma. She was then referred to the haematologist for chemotherapy.

	*Case 1*	*Case 2*	*Case 3*	*Case 4*	Case 5
Presentation	NS Obstructive Stridor	NS StridorHoarseness of voice	NS Airway obstruction	NS	NS
FNAC / Tru cut biopsy	Suspicious malignancy	Inconclusive	Not done	Lymphoma	lymphoma
Surgery	Emergency subtotal thyroidectomy	Emergency subtotal thyroidectomy	Emergency total thyroidectomy	None	None
Complication	None	None	Bleeding from op site	None	None
Outcome	No recurrence at 20 months	Lost to follow-up	No recurrence at 18 months	CT scan showed no recurrence and total regression at 16 months	Minimal thyroid tissue left at 14 months follow up

The treatment of thyroid lymphoma is mainly chemotherapy either employing the CHOP regime or other alternatives according to cell type. Over the years, multimodality treatment with radiotherapy has significantly reduced the recurrence rate from 37% to 7.7%². Recently with the advent of chimeric monoclonal antibody ( Rituximab ), the rate of complete remission is higher with R-CHOP than CHOP alone ( 29% vs. 16% ). Maintenance with rituximab also halves the risk of death. Monoclonal antibody combined with chemotherapy is sufficient as a definitive treatment for thyroid lymphoma³.

The role of surgery is only for diagnosis and debulking of a compressive tumour. Some will still argue that compression can be relieved with radiotherapy and while on it the patient could be intubated to maintain patency of the airway⁴. A morbidity associated with surgery for these patient as seen in one of our patient is development of esophageal cutaneous fistula

In our centre, the operation was initially performed due to inconclusive result of FNAC and obstructive symptoms. However we learned later that by doing tru cut biopsy, we can manage patient without surgery and therefore avoid the complication associated with surgery. There was complication associated with tru-cut biopsy as seen above where the patient developed intra-thyroidal haemorrhage needing emergency debulking surgery. It yields a better result in diagnosing thyroid lymphoma than FNAC. We advocate that for centres without immunohistochemistry facilities, a tru-cut biopsy is a better option than FNAC to achieve a diagnosis. However, as tru-cut biopsy is not without complication, the centre must have a good service in term of endocrine surgery should the biopsy encounter problems.

In summary, pre-operative thyroid lymphoma is difficult but can be achieved by tru-cut biopsy. It is a good alternative to immunohistochemistry for diagnosing thyroid lymphoma. Emergency thyroidectomy should be reserved for patients with severe airway obstruction.