An atypical metastatic pathway: Bilateral inguinal lymphadenopathy as the initial presentation of papillary thyroid carcinoma

Abstract

INTRODUCTION AND IMPORTANCE: Papillary thyroid carcinoma (PTC) is known to primarily manifest as a thyroid nodule with regional lymph node metastasis. Distant metastasis in PTC is rare, making its diagnosis challenging when presenting atypically. CASE PRESENTATION: A 47-year-old Sudanese female was evaluated for bilateral inguinal lymphadenopathy and significant weight loss. Extensive diagnostic efforts, including abdominal imaging and thyroid function tests, showed no abnormalities and no palpable thyroid nodules. However, a biopsy of the inguinal lymph nodes (ILNs) revealed psammoma bodies, confirming PTC. Further evaluation detected a 1 cm thyroid nodule. CLINICAL DISCUSSION: This case highlights the unusual presentation of PTC with distant metastasis to the ILNs without the typical presence of a thyroid nodule or cervical lymphadenopathy. The discovery underscores the importance of considering PTC in differential diagnoses for unexplained inguinal lymphadenopathy, emphasizing the need for thorough evaluation in atypical presentations. CONCLUSION: The rarity of inguinal lymphadenopathy as an initial presentation of PTC demonstrates significant diagnostic challenges. This case emphasizes the necessity of including PTC in the differential diagnosis for inguinal lymphadenopathy, advocating for comprehensive diagnostic strategies to manage and improve outcomes in such atypical cases. The patient's refusal of surgery and subsequent loss to follow-up culminating in undocumented death further complicate management in such rare presentations.