Failing to Regress Swelling – What Keeps an Elderly Female Ailing

Abstract

Swellings in the region of the head and neck are quite common in the elderly and are often neglected. Usually, they are always assumed to be benign. Unless it causes discomfort, disfigurement, or disturbance in day-to-day activities, it is seldom paid attention to. Very few of such cases would seek medical or surgical opinion. This case shows how sinister a benign-looking swelling in the region of the head and neck of the elderly can turn out to be. Follicular carcinoma of the thyroid is distinguished by its tendency for hematogenous spread. While lung and bone metastases are reported, extensive involvement of the skull, vertebrae, and paraspinal soft tissues is unusual and is presented here. Such presentations can mimic primary bone pathology and delay diagnosis.

INTRODUCTION

We report a rare, atypical case of a 61-year-old female having benign looking swelling that, after imaging and biopsy analysis, turned out to be follicular thyroid carcinoma with destructive metastases. This case highlights the diagnostic difficulties of FTC, the limitations of fine-needle aspiration cytology (FNAC) in follicular-patterned lesions, and the relevance of thyroid carcinoma in the differential diagnosis of atypical bone lesions.

This case illustrates the diagnostic challenges and atypical nature of metastatic follicular carcinoma of thyroid (FTC). The initial FNAC was inconclusive, and although repeat cytology suggested a follicular neoplasm, a definitive diagnosis required biopsy. Tissue sampling confirmed metastatic follicular carcinoma, and histopathology reaffirmed multiple metastatic sites. The occurrence of skull and vertebral metastases at presentation is particularly rare and highlights the importance of considering thyroid carcinoma in the differential diagnosis of destructive skeletal lesions. Systemic findings such as mild anemia and metabolic alterations, including suppressed TSH with elevated T3 and pre-diabetes, further complicated the clinical picture.

Accounting for nearly 10%–15% of cases, FTC is the second leading histological variant of thyroid cancer, ranking just after papillary carcinoma. Unlike papillary carcinoma, which spreads primarily via lymphatics, FTC demonstrates a propensity for hematogenous dissemination, most frequently involving the lungs and bones. Although bone metastases are reported in 10%–15% of cases at presentation, the skull and vertebrae are rarely affected, making such presentations diagnostically challenging and clinically significant.[1,2,3]

Metastatic thyroid carcinoma to the skull typically presents as painless, slow-growing swellings, which can be mistaken for primary bone tumours, vascular lesions, or meningiomas. Vertebral involvement is even less common but carries a risk of neurological compromise due to spinal cord compression. These atypical presentations can obscure the underlying thyroid origin, especially when the thyroid lesion is clinically silent or small.

CASE REPORT

A 61-year-old female presented with neck pain on and off for the past 6 months and swelling in the lower part of her head-occipital region for the past 2 years. Plain radiograph of cervical spine [Figure 1] showed approximately 6 cm × 7 cm-sized soft tissue lesion eroding the calvarium in occipital bone, an ill-defined soft tissue mass in the left paravertebral cervicothoracic region eroding the lateral aspect of transverse process of C7 and D1. Soft tissue swelling with coarse calcification was noted in the region of the neck anteriorly at the expected site of the thyroid gland.

Figure 1.

Plain radiograph of the neck and cervical spine, (a) Lateral view and (b) Anteroposterior view demonstrating soft tissue mass (white arrow) causing destruction of occipital bone (black arrows) and coarse calcifications in thyroid (white circle)

Plain and Contrast computed tomography (CT) scan better demonstrated the aggressive nature of swelling in the occipital region [Figure 2] as a heterogeneous moderately enhancing soft-tissue mass involving the-occipital bone more on the right side, involving scalp, eroding and destroying underlying bone, and affecting meninges without invading the brain parenchyma, encasing the right transverse sinus, consistent with a neoplastic mass. Although at this stage it could not be said with conviction whether mass was primary or secondary.

Figure 2.

Axial computed tomography (CT) scan of the brain; (a) Bone window image showing soft tissue mass (white arrows) causing destruction of occipital calvarium. (b) Plain nonenhanced CT scan - soft tissue window image showing iso-hyperdense mass, (c) Postcontrast axial CT image showing moderately enhancing heterogeneous destructive mass also encasing the right transverse sinus

Contrast CT scan of soft tissue mass in the left paravertebral cervico-thoracic region [Figure 3] also showed a heterogeneous moderately enhancing soft-tissue mass eroding the lateral aspect of the transverse process of C7 and D1 and lateral vertebral bodies and extending in the spinal canal to encase the spinal cord and to displace the spinal cord right laterally. Contrast CT also showed an enlarged thyroid gland with 3 cm × 4.5 cm nodular appearance and coarse calcifications in the right lobe and 2.3 cm × 3.5 cm nodular lesions in the left lobe with smaller calcifications, suggesting primary neoplasm. No significant cervical lymphadenopathy was noted.

Figure 3.

Axial computed tomography (CT) scan of the neck; (a) Plain nonenhanced CT scan - soft tissue window image showing iso-hyperdense mass, (b) Postcontrast axial CT image showing moderately enhancing heterogenous destructive mass (white arrows) invading lateral aspects of C7, D1 vertebral bodies and extending in the spinal canal to displace the cord to the right. Coarse calcifications in the enhancing nodule in thyroid showing by white circle

Plain and contrast magnetic resonance imaging (MRI) images [Figure 4] also confirmed the imaging findings of metastatic lesions in the occipital region of the skull and at the left paraspinal lower cervicothoracic location at C7 and D1 vertebral level with extension of mass in the spinal canal causing cord compression. MRI also demonstrated an enhancing lesion in the right as well as left lobes of thyroid-suggesting possible primary.

Figure 4.

Post contrast sagittal (a) image showing moderately enhancing destructive lesion involving occipital bone (vertical white arrow) and neoplastic mass in the right lobe of thyroid (horizontal white arrow) and (b) coronal image showing moderately enhancing lesion causing destruction of C7-D1 on left side and extending in the spinal canal

FNAC of the thyroid was performed, but reports came out to be inconclusive. However, in view of the destructive nature of lesions of occipital and cervico-thoracic regions, repeat ultrasound-guided FNAC [Figure 5a] was performed, which demonstrated follicular neoplasm (Bethesda IV). A biopsy from the left cervical paraspinal mass [Figure 5b] confirmed metastatic lesions arising from primary of follicular carcinoma of the thyroid.

Figure 5.

(a) Fine-needle aspiration cytology smears showing cohesive clusters and microfollicular patterns of thyroid follicular epithelial cells with nuclear crowding and occasional grooves, set against a haemorrhagic background with scant colloid (H and E, ×40). Findings are consistent with Bethesda Category IV for follicular neoplasm. (b) Biopsy sections showing thyroid tissue with colloid-filled follicles lined by cuboidal to columnar follicular epithelial cells exhibiting nuclear crowding, hyperchromasia, and focal microfollicular arrangements (H and E, ×40). The overall features are consistent with follicular carcinoma of the thyroid with metastatic deposits

DISCUSSION

Unlike papillary carcinoma, which spreads primarily via lymphatics, FTC disseminates hematogenously, most often to the lungs and bones. However, metastases to the skull and vertebrae are rare, representing <3% of cases, and often present diagnostic challenges.

When compared with published studies, our case demonstrates both similarities and differences. Metastases to unusual sites such as ribs and vertebrae have been reported,[4] along with the mandible,[5] chest wall lymph nodes.[6] scalp,[7] iliac bone, mimicking appendicitis,[8] and the brain.[9] Other reports described functional metastases with thyrotoxicosis, controlled either by Lenvatinib[10] or by propylthiouracil and serial radioiodine therapy.[11] In contrast, thyroid crisis due to metastatic FTC was reported in a very elderly patient with a poor outcome despite supportive care.[12] In contrast to the case series by Bailey et al. (2023), where postthyroidectomy FTC patients developed skull and brain metastases managed with radioiodine ablation, our patient presented with skull and vertebral metastases at the time of initial diagnosis, before definitive thyroid surgery.[13] This highlights the atypical nature of our case, where destructive skeletal lesions preceded recognition of the thyroid primary, underscoring the importance of considering FTC in the differential diagnosis of unusual cranial and spinal lesions.

Unlike these cases, our patient presented with combined skull and vertebral metastases, confirmed histo-pathologically, an especially rare distribution. The initial symptoms of occipital swelling and neck pain were attributable to these skeletal deposits, which delayed suspicion of a thyroid primary. Previous case studies highlighted that skull metastases often dominated the presentation, concealing the thyroid origin.[9] In our case, the initial FNAC was inconclusive, while repeat cytology (Bethesda IV) suggested a follicular neoplasm but remained indeterminate; definitive diagnosis was established by paraspinal mass biopsy, emphasizing the value of tissue sampling from accessible metastatic sites when cytology is equivocal. The laboratory profile contributed to the complexity of clinical interpretation. Biochemical profile showing decreased TSH with elevated T3 levels suggested possible tumour activity or therapy effect, while mild anemia and prediabetes contributed to morbidity. Therapeutically, total thyroidectomy with radioactive iodine ablation remains standard for resectable FTC with distant metastasis.

This case reinforces the need to consider thyroid carcinoma in the differential diagnosis of destructive skull and vertebral lesions, especially in elderly females with systemic symptoms, and exemplifies the stepwise path from inconclusive cytology to biopsy-proven diagnosis in metastatic FTC.

CONCLUSION

Follicular thyroid carcinoma can rarely present with atypical and advanced skeletal metastases. Early recognition, repeat cytological evaluation, and histopathological confirmation are critical for diagnosis. Clinicians should maintain a high index of suspicion when evaluating unusual skull or vertebral lesions, as timely diagnosis impacts management and prognosis.

Benign looking swelling in the head and neck of elderly patients are not always benign, as proven by this case. Each such case should be thoroughly evaluated. Follicular thyroid carcinoma can present with atypical and advanced osseous metastases, with uncommon sites including the skull and vertebrae. This case brings attention to the importance of maintaining a high index of suspicion for thyroid carcinoma in patients with destructive cranial or vertebral lesions. Early detection, repeat cytological evaluation, and histopathological confirmation from metastatic sites are vital for swift diagnosis and management, which directly impact the patient outcomes.

Declaration of patient consent

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

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.