Rare Papillary Thyroid Cancer Masquerading as Acute Suppurative Thyroiditis in Adolescent

Abstract

Acute suppurative thyroiditis is a condition that is rare but dangerous, which may turn from innocent to life-threatening in a short time if left untreated. Classically, acute suppurative thyroiditis results from bacterial infection and may lead to abscess formation. We report a case presentation of a 17-year-old male who initially presented with a thyroid abscess.  Despite aggressive treatment of the abscess, the patient failed to show clear predisposing risk factors and demonstrated persistent symptoms. Therefore, further investigations were conducted. With close monitoring and more diagnostic testing being done, the final diagnosis for this patient was papillary thyroid cancer. He underwent successful surgical intervention with uneventful subsequent recovery. This case, therefore emphasizes a need for lifelong follow-up of patients with thyroid abscesses especially when the classic risk factors are absent. Secondly, it points out to continue with a high index of suspicion for a hidden malignancy in them because even if timely diagnosis and treatment are instituted, the results are excellent. Even this review includes a discussion about the literature on similar cases to provide a clearer view in terms of existing thyroid abscesses and the chances or possibility of co-existence of underlying thyroid malignancies.

Introduction

Acute suppurative thyroiditis is a rare but serious infection in the thyroid gland, often presenting acutely with sudden onset of neck pain, fever, and swelling. Generally, it originates as a bacterial infection, which can easily turn into an abscess if not treated. The infection is usually seen in the presence of predisposing factors, including congenital abnormalities, recent surgery, or immunosuppression. Yet, in very rare situations, there is an underlying malignancy, masquerading as an abscess.

We present a case of a 17-year-old male who, despite a lack of identifiable risk factors, presented with a thyroid abscess. His condition did not improve with appropriate treatment and continued unabated. Thus, further evaluation was warranted, finally, leading to a diagnosis of papillary thyroid cancer, a rather rare scenario, and therefore, it serves as an illustration of the importance of adequate and continuous assessments in the diagnostic pathways of similar cases.

Case Presentation

Patient Background

This is a case of a previously healthy 17-year-old male who came into the emergency department with complaints of a painful swollen neck, fever, and difficulty swallowing. All these symptoms had been there for one week. He had no recent infections, trauma, or surgery.

There was a tender, enlarged thyroid gland on physical examination with notations of warmth and erythema over the overlying skin. His basic vitals had a low-grade fever of 38.2°C. He had lab test findings of elevated white blood cell counts, indicating an acute inflammatory process.

Initial Diagnosis and Management

The patient was presumptively diagnosed with acute suppurative thyroiditis based on the clinical presentation. A neck ultrasound was conducted, where a fluid-filled lesion consistent with an abscess in the left thyroid lobe was found. FNA of the abscess was performed, and purulent material was aspirated. Bacterial cultures were obtained from the site, and the patient was initiated on broad-spectrum intravenous antibiotics to cover for the common bacterial pathogens: Staphylococcus aureus and Streptococcus species.

The patient's symptoms did well following the drainage and antibiotic therapy. His fever, however, persisted, and his neck pain was not fully relieved. A repeat ultrasound demonstrated an absence of abscess reformation, but a suspicious solid nodule appeared in the right thyroid lobe. With this unusual clinical course and the persistence of symptoms despite appropriate management, the need for further evaluation was clear.

Further Diagnostic Evaluation

A contrast-enhanced CT scan of the neck was performed to further evaluate the thyroid and surrounding structures. The scan revealed a solid mass in the right lobe of the thyroid measuring 2.5 cm in diameter, with associated lymphadenopathy. These findings raised the suspicion of an underlying malignancy, prompting an FNA biopsy of the solid mass.

The biopsy results confirmed the presence of papillary thyroid carcinoma (PTC), a well-differentiated thyroid cancer that often presents as a solitary thyroid nodule. Although thyroid abscesses are rare, PTC masquerading as acute suppurative thyroiditis is even more unusual. Given the patient’s age and the absence of predisposing factors for infection, the diagnosis of PTC was considered the likely underlying cause of the thyroid abscess formation.

Surgical Management and Pathological Findings

The patient was referred to a surgical oncology team for definitive management. He underwent a total thyroidectomy with central neck dissection. During the surgery, the mass in the right thyroid lobe was excised, along with affected lymph nodes.

Histopathological analysis confirmed the diagnosis of papillary thyroid carcinoma with lymph node involvement. The tumor was classified as moderately differentiated, with no evidence of distant metastasis. The left thyroid lobe, where the abscess had initially formed, showed no residual malignancy but exhibited signs of inflammation, likely secondary to the abscess formation.

Postoperative Course and Follow-up

The patient’s postoperative course was uneventful, and he was discharged on postoperative day three. He was started on levothyroxine replacement therapy to maintain normal thyroid hormone levels and suppress TSH to prevent cancer recurrence.

At his one-year follow-up, the patient remained disease-free, with no evidence of recurrence on ultrasound or serum thyroglobulin levels. He continues to be monitored by his endocrinologist and surgical oncology team, with regular imaging and laboratory evaluations planned for the foreseeable future.

Discussion

Acute suppurative thyroiditis is a rare condition, particularly in young, healthy patients who lack predisposing conditions such as immunosuppression, trauma, or anatomical abnormalities. In such patients presenting with an abscess in the thyroid, common and uncommon causes must be considered. The case presented here is unique because the cause of the abscess was an underlying papillary carcinoma of the thyroid; only a few such case reports are reported in the literature.

Indeed, papillary thyroid cancer is the most common variety of thyroid malignancies, representing around 85% of all thyroid cancer cases. This carcinoma grows slowly and has an excellent prognosis if diagnosed early. However, the association of PTC with the formation of abscesses in the thyroid has been less known so far. Some hypothesize that the necrotic center of the tumor causes bacterial seeding and thus gives way to the formation of an abscess.

A young man with an abscess: Unexpected diagnosis of PTC. This is a typical story of a syndrome that presents with an unexpected diagnosis, as mentioned in the introduction of the chapter. Because this patient improved on appropriate treatment of the abscess, follow-up by the doctor would have helped identify the problem when his clinical course began to deviate from what was expected.

Literature Review

A review of the literature reveals only a handful of similar cases where thyroid abscesses were associated with underlying malignancies, particularly papillary thyroid carcinoma. In most cases, the abscess is treated successfully with drainage and antibiotics, and the malignancy is discovered only after the patient fails to respond to standard treatment.

Several studies have highlighted the importance of considering malignancy in cases of thyroid abscesses that do not resolve as expected. In these cases, imaging modalities such as ultrasound, CT, and MRI play a crucial role in identifying suspicious lesions and guiding further diagnostic interventions like FNA biopsy.

Conclusion

This case underlines the precaution in the management of thyroid abscesses, particularly in asymptomatic patients who do not have any other predisposing factors for infection. Although acute suppurative thyroiditis is a rare disease process, an underlying malignancy should always be considered whenever the clinical course has followed an atypical course. Papillary thyroid carcinoma formed the underlying cause of the thyroid abscess, and appropriate surgical intervention allowed for an excellent outcome in this case. This case once again reminds us that both clinical and radiological correlation with proper pathological evaluation is essential to reach a diagnosis and undertake appropriate management of rare thyroid diseases promptly.

References

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