Thyroid Sporadic Goiter with Adult Heterotopic Bone Formation

Abstract

Thyroid heterotopic bone formation (HBF) in goiter is a rare finding. Five thyroid resection specimens were analyzed for HBF. The results were correlated with clinicomorphological features. All patients were women (33–82 years). The preoperative diagnosis was thyroid goiter or nodule. Treatment consisted in thyroidectomy and lobectomy (3 and 2, resp.). Microscopy showed sporadic nodular goiter. Malformative blood vessels and vascular calcifications were seen in intra- and extrathyroid location (5 and 3, resp.). The number and size of HBFs (total: 28) ranged between 1 and 23/thyroid gland (one bilateral) and 1 and 10 mm, respectively. Twelve HBFs were in contact with the thyroid capsule. Most were extranodular (21, versus 6 intranodular). The medical history was positive for dyslipidemia, hyperglycemia, renal dysfunction, and hyperuricemia (2, 3, and 3 cases and 1 case, resp.) without any parathyroid abnormality. In conclusion, thyroid HBF may be characterized by subcapsular or extranodular location, various size (usually ≥2 mm), and vascular calcifications and malformations. Features of metabolic syndrome and renal dysfunction may be present, but their exact role in the pathogenesis of HBFs remains to be elucidated.

Mature bony metaplasia in multinodular goiter: A case report

“…The presence of macrocalcification on the ultrasound in our case raised the suspicion that the calcified nodule may be malignant. This can be a diagnostic pitfall especially in the presence of osteoclasts in frozen section [6,15]. The extensive fibrosis present in our case was comparable to the cases reported by Handra-Luca et al [6].…”

“…Of the changes commonly observed, dystrophic calcification is well-appreciated. However, osseous metaplasia with mature bone formation, as in our case, is extremely rare with only 13 cases reported in the English literature [6,7]. Our case was of an adult female and this was comparable to other reports [10].…”

“…This can be a diagnostic pitfall especially in the presence of osteoclasts in frozen section [6,15]. The extensive fibrosis present in our case was comparable to the cases reported by Handra-Luca et al [6]. However, no inflammation was present and Riedel thyroiditis was excluded due to the absence of extrathyroid extension [16].…”

“…The thyroid function was normal in our case as documented in most of the reported cases. Only three reports documented hyperthyroidism [6,17,18].…”

“…Osseous metaplasia with ectopic bone formation is extremely rare in benign thyroid disorders. To the best of our knowledge, only thirteen cases of sporadic goiter with heterotopic bone formation are reported [6,7]. In line with SCARE criteria, we present a 44-year-old lady with multinodular goiter showing histological osseous metaplasia and lamellar bone formation [8].…”