Article Type : Case Report
Title : Papillary Thyroid Carcinoma with Scalp Metastasis: A Rare Case Report
Authors : Shubhangi Belekar
Abstract : Papillary thyroid carcinoma (PTC) is the most common malignant tumor of the thyroid gland and generally has an excellent prognosis with regional lymph node metastasis being common. Distant metastasis is relatively uncommon and frequently involves the lungs and bones. Cutaneous metastasis, particularly to the scalp, is extremely rare and usually indicates advanced disease with poor prognosis. We report a rare case of papillary thyroid carcinoma presenting with scalp metastasis in a middle-aged female. The patient presented with a rapidly growing scalp nodule and thyroid swelling. Fine needle aspiration cytology (FNAC) from the scalp lesion and thyroid revealed features of papillary carcinoma. The patient underwent total thyroidectomy with excision of the scalp lesion followed by radioactive iodine therapy. This case highlights the importance of considering metastatic thyroid carcinoma in the differential diagnosis of scalp nodules and emphasizes the role of cytology and histopathology in diagnosis.
Introduction : Papillary thyroid carcinoma (PTC) accounts for approximately 80–85% of all thyroid malignancies and predominantly affects females in the third to fifth decades of life( 1). It generally exhibits indolent behavior with high survival rates when diagnosed early. Regional lymph node involvement is common; however, distant metastasis occurs in only 2–5% of cases, most frequently to the lungs and bones. Cutaneous metastasis from PTC is exceptionally rare, with the scalp being the most commonly reported site (2). Such metastases often indicate disseminated disease and are associated with poor prognosis. Due to its rarity, scalp metastasis may be misdiagnosed as a benign skin lesion, leading to delayed treatment. This case report describes a rare presentation of PTC with scalp metastasis and discusses its clinicopathological significance (3).
Case Presentation : A 48-year-old female presented to the outpatient department with a painless nodular swelling over the parietal region of the scalp for two months, which had rapidly increased in size over the last three weeks. There was no history of trauma, ulceration, or discharge from the lesion. The patient also reported a gradually enlarging anterior neck swelling for the past one year associated with mild dysphagia but no voice change or symptoms of hyperthyroidism or hypothyroidism.
On physical examination, a firm, non-tender, mobile nodule measuring 3 × 2.5 cm was noted over the parietal scalp region. The overlying skin was intact. Examination of the neck revealed a solitary, firm thyroid nodule in the right lobe measuring approximately 4 cm, moving with deglutition. No significant cervical lymphadenopathy was noted.
Thyroid function tests were within normal limits. Ultrasonography of the neck showed a hypoechoic thyroid nodule with microcalcifications in the right lobe. Fine needle aspiration cytology (FNAC) from the thyroid nodule revealed features suggestive of papillary thyroid carcinoma, including papillary fronds, nuclear grooves, intranuclear cytoplasmic inclusions, and overlapping nuclei. FNAC from the scalp lesion also showed clusters of malignant epithelial cells with similar nuclear features, suggestive of metastatic papillary carcinoma.
The patient underwent total thyroidectomy with excision of the scalp lesion. Gross examination of the thyroid revealed a well-circumscribed gray-white tumor in the right lobe. Histopathological examination confirmed the diagnosis of classic papillary thyroid carcinoma. The scalp lesion also showed metastatic deposits of papillary carcinoma within the dermis. Postoperatively, the patient received radioactive iodine ablation therapy and was started on suppressive thyroxine therapy. At six months of follow-up, the patient was clinically stable with no evidence of recurrent disease.
Discussion : Papillary thyroid carcinoma is known for its favorable prognosis and slow progression. It commonly spreads via lymphatics to regional cervical lymph nodes. Hematogenous spread is rare and typically involves lungs and bones4. Cutaneous metastasis is an extremely uncommon manifestation of thyroid carcinoma, with reported incidence of less than 1%. Among cutaneous sites, the scalp is the most frequent due to its rich vascular supply5.
Scalp metastasis often presents as a solitary or multiple rapidly growing nodules and may be mistaken for benign conditions such as epidermoid cysts, lipomas, or pyogenic granulomas. In many reported cases, scalp metastasis has been the first presenting feature of an undiagnosed thyroid malignancy6. The presence of skin metastasis usually indicates advanced disease and carries a poor prognosis.
FNAC plays a crucial role in the diagnosis of both the primary thyroid lesion and metastatic deposits. The characteristic nuclear features of papillary carcinoma are often preserved even in metastatic sites, aiding in accurate diagnosis. Histopathology remains the gold standard for confirmation7-9.
The mainstay of treatment includes total thyroidectomy followed by radioactive iodine therapy and thyroid-stimulating hormone suppression with levothyroxine. Surgical excision of cutaneous metastasis is recommended for local control and symptomatic relief. Despite aggressive treatment, patients with cutaneous metastasis generally have reduced survival due to widespread disease10.
Early recognition of unusual metastatic sites and prompt intervention can improve quality of life and may prolong survival. This case emphasizes the need for thorough evaluation of atypical scalp nodules, especially in patients with thyroid swellings.
Scalp metastasis from papillary thyroid carcinoma is an extremely rare clinical presentation and usually signifies advanced disease. A high index of suspicion is required when evaluating rapidly growing scalp nodules, particularly in patients with coexisting thyroid lesions. FNAC and histopathological examination are invaluable for early diagnosis. Timely surgical intervention combined with radioactive iodine therapy remains the cornerstone of management. Reporting such rare cases contributes to better understanding of the disease spectrum and aids in early diagnosis and appropriate management.
1. Katoh R, et al. Papillary thyroid carcinoma: clinical features and prognostic factors. Pathol Int. 1999;49:233–238.
2. Dahl PR, Brodland DG, Goellner JR, et al. Thyroid carcinoma metastatic to the skin: a cutaneous manifestation of a widely disseminated malignancy. J Am Acad Dermatol. 1997;36:531–537.
3. Lookingbill DP, Spangler N, Helm KF. Cutaneous metastases in patients with metastatic carcinoma: a retrospective study. J Am Acad Dermatol. 1993;29:228–236.
4. Costa J, et al. Cutaneous metastasis of papillary thyroid carcinoma. Thyroid. 2004;14:241–244.
5. Alcaraz I, et al. Cutaneous metastases from internal malignancies: a clinicopathologic and immunohistochemical review. Am J Dermatopathol. 2012;34:347–393.
6. Wu MH, et al. Scalp metastasis from papillary thyroid carcinoma: a case report. Kaohsiung J Med Sci. 2008;24:102–106.
7. Cirocchi R, et al. Papillary thyroid carcinoma with cutaneous metastasis: a rare clinical entity. Int J Surg Case Rep. 2013;4:76–79.
8. Hidaka Y, et al. Cutaneous metastasis from papillary thyroid carcinoma. Endocr J. 1999;46:777–779.
9. Rosai J. Rosai and Ackerman’s Surgical Pathology. 11th ed. Elsevier; 2018.
10. DeLellis RA, et al. WHO Classification of Tumours of Endocrine Organs. 4th ed. IARC, Lyon; 2017.