Journal of Dr. NTR University of Health Sciences

: 2019  |  Volume : 8  |  Issue : 1  |  Page : 75--76

Bilirubin crystals in thyroid

Rashmi Patnayak1, Kaushambi Chakraborty1, Rajesh Bhola1, Amitabh Jena2,  
1 Department of Pathology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India
2 Department of Surgical Oncology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha, India

Correspondence Address:
Dr. Rashmi Patnayak
Department of Pathology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha

How to cite this article:
Patnayak R, Chakraborty K, Bhola R, Jena A. Bilirubin crystals in thyroid.J NTR Univ Health Sci 2019;8:75-76

How to cite this URL:
Patnayak R, Chakraborty K, Bhola R, Jena A. Bilirubin crystals in thyroid. J NTR Univ Health Sci [serial online] 2019 [cited 2019 Dec 10 ];8:75-76
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Full Text

To the editor

Information regarding the presence of crystals in thyroid FNAC in the literature is sparse. Cytological images of crystals in thyroid FNAC are available in very few articles.[1] But within the colloid of normal thyroid glands, crystals are known to be present. They are usually variable in size and shape, and be difficult to identify under light microscopy. However, most of the crystals are strongly birefringent and can be easily detected under polarized light microscopy.[1]

A 51-year-old female attended surgery outpatient department with the complaint of neck swelling since last 15 years. She gave a history that the swelling was initially small in size but for the last 10 days it was increasing and has attended the present size of 12 × 5 cms. [Figure 1]a Ultrasonography (USG) of neck showed grossly enlarged thyroid gland. It was reported as colloid goiter. [Figure 1]b On fine needle aspiration cytology (FNAC), 5 ml of brownish fluid was aspirated. The smears did not reveal any thyroid follicular cells. There were many flat rectangular and needle shaped crystals noted in a background showing inflammatory cells. [Figure 1]c, [Figure 1]d and [Figure 1]a The cytology was reported as non-diagnostic aspiration. (Bethesda category – I). These crystals were visualized under polarizing microscope. They were not birefringerent. [Figure 1]e and [Figure 2]b, [Figure 2]c The rectangular crystals with broken window pane appearance were cholesterol crystals and the other slender needle like brownish crystals were bilirubin crystals.{Figure 1}{Figure 2}

Birefringent crystals were found more in benign thyroid diseases in comparison to malignant tumors as illustrated by different studies.[2],[3] Multifocal distribution of birefringent crystals was also more common in benign diseases unlike malignant tumors.[2],[3] Plate-like cholesterol crystals are seen in colloid nodules with cystic degeneration.[4] In our case, we noted cholesterol crystals. In addition, there were bilirubin crystals. Presence of both these crystals with USG report of colloid goiter can be explained as a result of degenerative changes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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1Wong KS, Lewis JS, Jr, Gottipati S, Chernock RD. Utility of birefringent crystal identification by polarized light microscopy in distinguishing thyroid from parathyroid tissue on intraoperative frozen sections. Am J Surg Pathol 2014;38:1212-9.
2Katoh R, Kawaoi A, Muramatsu A, Hemmi A, Suzuki K. Birefringent (calcium oxalate) crystals in thyroid diseases. A clinicopathological study with possible implication for differential diagnosis. Am J Surg Pathol 1993;17:698-705.
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