A case of Langerhans cell histiocytosis of the thyroid gland.
C Feeney, M Reddy, Robinson S and Tolley N.
Imperial Centre for Endocrinology
A 44 year old woman presented to the combined ENT/Endocrinology thyroid clinic with a short history of neck swelling which was confirmed to be a smooth goitre on clinical examination. Initial blood tests results were as follows: TSH 0.24 mu/L (0.30-4.20), T4 8.2pmol/L(9-19), TPO antibody negative, PTH 6.4pmol/L (1.1-6.8) and 25 OH Vitamin D <15 nmol/L (25-100). Repeat thyroid function showed TSH 4.85 mu/L and T4 <5.2 pmol/L and she was commenced on thyroxine replacement.
An ultrasound of the neck demonstrated a diffuse abnormality of the thyroid gland with a generalised hypoechoic echotexture, widespread microcalcification and level 6 lymphadenopathy. The right lobe was particularly enlarged, but no specific focal lesions were identified. FNA of the thyroid was suggestive but not diagnostic of medullary carcinoma. Carcinoembryonic antigen (CEA) was mildly elevated at 6.5 ug/L (1-5) but calcitonin was undetectable.
Following discussion at the thyroid MDT, a total thyroidectomy was recommended. However, dissection of the left lobe was technically challenging and a left hemi-thyroidectomy only was performed as the Recurrent Laryngeal Nerve failed to stimulate post lobectomy. As the pathology was unknown at the time it was decided not to embark upon surgery on the right side.
Histologically, histiocytes were seen on a background of numerous eosinophils and a lymphoid infiltrate. Immunohistochemistry revealed positivity for CD1a and S-100. These features were in keeping with a definitive diagnosis of Langerhans cell histiocytosis.
During a post-operative review it was noted that she had developed multiple skin lesions suggestive of multifocal involvement and she was referred for a dermatology review. Since then she has been found to have complete anterior pituitary dysfunction and she is currently being investigated further elsewhere.
Langerhans cell histiocytosis is a disease caused by clonal proliferation of a group of antigen-presenting cells known as Langerhans cells. Its manifestations range from isolated lesions to multisystem disease involving various organs such as bone, skin and the pituitary stalk. Thyroid involvement has been reported in the literature, but remains rare and its management is challenging.