Fibromatosis of thyroid gland (a case report).AB Samsi, HK Shah, A Vaidya, PR Pai, U Deshmane, SY Sane
Dept. of Surgery, Seth G.S. Medical College, Parel, Bombay.
Correspondence Address: Source of Support: None, Conflict of Interest: None PMID: 0001512725
Source of Support: None, Conflict of Interest: None
Fibromatosis of thyroid gland is a rare condition encountered in surgical practice. Clinically presenting as goitre, it is treated with near total thyroidectomy with good results. We had one such case under our care at the K.E.M. Hospital, Bombay. Rarity of this condition prompted us to publish the data, the literature is briefly reviewed.
Keywords: Case Report, Fibroma, pathology,surgery,Goiter, Nodular, pathology,surgery,Human, Male, Middle Age, Thyroid Gland, pathology,Thyroid Neoplasms, pathology,surgery,Thyroidectomy,
Fibromatosis of the head and neck region is a curio s clinical entity, demanding accurate microscopic identification. Fibromatosis, though reported in the above mentioned region, isolated affection of thyroid gland is not reported in available literature. This case treated by near total thyroidectomy with good results is reported with review of available literature.
A 60-year-old male of Garwhal Community from subhimalayan district of Dehradun, India presented with the history of painless gradually increasing swelling of 5 months duration in right lower part of the anterior triangle of neck. Apart from mild dysphagia and dyspnoea, there were no other symptoms.
Vital parameters of the patient on examination were normal. Locally, the patient had a 7cm x 5 cm uninodular goitre, which was found to be non-tender, hard in consistency and deviating trachea to the left. Kocher's test was negative. Cervical nodes were not palpable. There were no signs suggestive of toxicosis or malignancy.
Haemogram and thyroid function tests were normal. Radiograph of the neck revealed spotty calcific areas in the region of the nodule with displacement of trachea to the left. Scan confirmed the uninodular goitre with a cold area. Fine needle aspiration cytology was suggestive of spindle cell tumour or neurogenic tumour
The tumour was seen to be adherent to muscles during surgery. Near total thryoidectomy was carried out. Post-operative course was uneventful. At 1 year follow-up the patient was found to be normal.
On gross examination, the specimen of thyroid showed an ovoid mass replacing the right lobe. It measured 5 x 6 x 3 cm. The surface was nodular covered by a capsule with attached muscle fibres. Cut surface revealed large area of hyalinisation at the center with only a rim of yellowish white dense fibrous tissue at the periphery. The left lobe and the isthmus were normal. There were no satellite nodules or lymph node metastasis.
Histologically, the mass of the right lobe showed acellular hyalinised central area surrounded by proliferating fibroblasts. These cells were arranged in bundles and showed few mitosis. There was diffuse sprinkling of lymphcytes and plasma cells. Few vessels towards the centre showed obliteration. There was no identifiable thyroid tissue, Hurthle cells or lymphoid follicles in the mass. Few skeletal muscle fibres were seen trapped at the periphery and hence the diagonsis of fibromatosis of thyroid gland was entertained (See [Figure:1]).
Fibromatosis is common in neck because the fibrous tissue elements in the neck are concentrated in the various muscles and fascial spaces. On histological grounds, fibromatosis of thyroid has to be differentiated from low grade fibrosarcoma and fibrous histocytoma. Large area of hyalinisation, inflammatory infiltration and rare mitoses forms the benigh nature of the lesion.
Hard fibrous mass in thyroid is usually clinically considered as Riedel's thyroiditis. It is a diffuse process thought to be an end stage of thyroditis. Riedel's thyroiditis of this kind on histology appears similar to fibromatosis, yet can be distinguished by atrophic thyroid acini trapped in the hyalinising fibrous tissue.
In our case, the mass was located to the right lobe. The central large area of hyalinisation was rimmed with proliferating fibroblastic and inflammatory cells. It trapped the surrounding muscle and corincetive tissue as in seen in fibromatosis at other sites. Such a lesion is described as a type of Riedel's thyroiditis, a condition not related to Hashimoto's thyroiditis.
It represents manifestation of a group of idiopathic disorders generally known as inflammatory fibrosclerosis. As such, it may be seen co-existing with mediastinal retroperitioneal fibrosis, sclerosing cholangitis or inflammatory pseudotumour of the orbit.
On follow up our patient was found to be asymptomatic for one year after surgery as compared to a marked high relapse rate reported by HJ Sommer.
We thank Dr. PM Pai, the Dean, Seth GS Medical College and King Edward Memorial Hospital, Bombay for allowing us to publish the Hospital data.