Anaplastic thyroid carcinoma with chondrosarcomatous differentiation: a case report

Area of Science:

• Pathology
• Oncology
• Surgical Pathology

Background:

• Anaplastic thyroid carcinoma (ATC) is a rare and aggressive thyroid malignancy.
• Known morphological variants of ATC include paucicellular, angiomatoid, lymphoepithelioma-like, and small-cell types.
• A variant of ATC exhibiting chondrosarcomatous differentiation has not been previously reported.

Observation:

• A 63-year-old male presented with a cervical mass, and imaging revealed a left thyroid lobe lesion and two right thyroid lobe nodules.
• Histopathological examination of the left lobe tumor showed spindle sarcoma-like cells and abundant chondroid matrix production with atypical chondrocytes.
• Immunohistochemistry revealed vimentin positivity in spindle cells, with negative staining for common thyroid markers.

Findings:

• The resected tumor exhibited features of anaplastic thyroid carcinoma with distinct chondrosarcomatous differentiation.
• The spindle cells were positive for vimentin, indicating a mesenchymal origin, and negative for epithelial markers.
• The chondrocytes within the cartilaginous areas showed mild to moderate atypia.

Implications:

• This case expands the recognized histopathological spectrum of anaplastic thyroid carcinoma.
• The identification of chondrosarcomatous differentiation in ATC highlights the diverse potential morphologies of this tumor.
• Understanding these rare variants is crucial for accurate diagnosis and potentially tailored therapeutic strategies in thyroid cancer.