CR2. Extranodal Extension of Papillary Thyroid Carcinoma Masquerading as a Massive Intrathoracic Cyst
Presented During: Resident Case Report Competition
NYU Langone Medical Center
NY
United States - Contact Me
Camille Yongue is a PGY4 in the I6 Cardiothoracic Residency at NYU Langone. She completed her MD at Case Western Reserve University School of Medicine and BS at Skidmore College.
Saturday, May 2, 2026: 6:27 PM - 6:37 PM
Description
Papillary thyroid carcinoma (PTC) most commonly metastasizes to cervical lymph nodes. There are only rare reports of PTC presenting first as a primary lung lesion, and even fewer as a mediastinal mass rather than within the lung parenchyma. We present a case of an incidentally found massive intrathoracic cystic lesion with a normal appearing thyroid on axial computer tomography (CT) imaging who was then found to have disseminated papillary thyroid carcinoma.
This patient is a 63-year-old sheep farmer from Guyana who presented with a known 12.3cm intrathoracic mass which had been present for 30 years. Based on its appearance on CT scan and MRI of the neck, the pre-operative differential included an ecchinococcal cyst or bronchogenic cyst. Axial imaging suggested the mass was encapsulated by the right upper lobe (RUL) with calcifications present on the cyst edges and a 2cm mural nodule noted on the inferior portion.
In the OR the chest was free of pleural adhesions. Due to the size of the mass and presumed likely ecchinococcal etiology, an anterior thoracotomy was made in the 5th interspace to facilitate safe removal. To decrease the mass size, needle aspiration was performed and 30% hypertonic saline was injected for sterilization of possible cyst contents. With the mass decompressed, circumferential dissection was performed. Of note, the mass did not involve the right lung but rather had displaced the entire RUL secondary to mass effect. After removal the cyst was opened on a back table and contained ~500cc of brown fluid.
The patient was extubated at the end of the case and he was discharged on post operative day 3 without complications. Final pathology demonstrated lymphoid cells with well differentiated papillary thyroid carcinoma, positive for TTF1 and thyroglobulin. He was then referred to Otolaryngology and underwent dedicated neck ultrasound which demonstrated a right sided 2cm thyroid nodule with high-risk features and an enlarged level 4 node concerning for metastatic disease. He underwent total thyroidectomy, right central neck dissection and right lateral neck dissection. Final pathology demonstrated bilateral multifocal PTC, 4/7 central neck nodes and 3/15 of lateral neck nodes with metastatic disease. He is planned for radioactive iodine therapy.
This case illustrates a rare example of metastatic papillary thyroid carcinoma presenting as a massive intrathoracic cyst. In retrospect, this cyst had some characteristic features of an enlarged lymph node including calcifications and the absence of daughter cysts. It is odd that the thyroid was radiographically normal and that the cystic lymph node was displaced down into the thoracic cavity when these nodes more commonly displace structures in the neck. However, it does illustrate a key diagnostic pearl of thyroid cancer which is that it is best diagnosed using a dedicated thyroid ultrasound; CT or MRI of the neck is not the optimal imaging modality for examining thyroid tissue and a negative scan should not be used to rule out thyroid disease. Interestingly, this patient had this mass for several decades and thus his thyroid disease may have progressed after the cyst was already present.
Authors
Camille Yongue (1), Michael Dorsey (2), Arianna Winchester (3), Michael Persky (3), Xiaoqing O'Leary (4), Amie Kent (3)
Institutions
(1) NYU Langone Medical Center, NY, (2) NYU Langone Health, New York, NY, (3) NYU Langone Health, New York, NY, (4) NYCHHC Bellevue, New York, NY
This patient is a 63-year-old sheep farmer from Guyana who presented with a known 12.3cm intrathoracic mass which had been present for 30 years. Based on its appearance on CT scan and MRI of the neck, the pre-operative differential included an ecchinococcal cyst or bronchogenic cyst. Axial imaging suggested the mass was encapsulated by the right upper lobe (RUL) with calcifications present on the cyst edges and a 2cm mural nodule noted on the inferior portion.
In the OR the chest was free of pleural adhesions. Due to the size of the mass and presumed likely ecchinococcal etiology, an anterior thoracotomy was made in the 5th interspace to facilitate safe removal. To decrease the mass size, needle aspiration was performed and 30% hypertonic saline was injected for sterilization of possible cyst contents. With the mass decompressed, circumferential dissection was performed. Of note, the mass did not involve the right lung but rather had displaced the entire RUL secondary to mass effect. After removal the cyst was opened on a back table and contained ~500cc of brown fluid.
The patient was extubated at the end of the case and he was discharged on post operative day 3 without complications. Final pathology demonstrated lymphoid cells with well differentiated papillary thyroid carcinoma, positive for TTF1 and thyroglobulin. He was then referred to Otolaryngology and underwent dedicated neck ultrasound which demonstrated a right sided 2cm thyroid nodule with high-risk features and an enlarged level 4 node concerning for metastatic disease. He underwent total thyroidectomy, right central neck dissection and right lateral neck dissection. Final pathology demonstrated bilateral multifocal PTC, 4/7 central neck nodes and 3/15 of lateral neck nodes with metastatic disease. He is planned for radioactive iodine therapy.
This case illustrates a rare example of metastatic papillary thyroid carcinoma presenting as a massive intrathoracic cyst. In retrospect, this cyst had some characteristic features of an enlarged lymph node including calcifications and the absence of daughter cysts. It is odd that the thyroid was radiographically normal and that the cystic lymph node was displaced down into the thoracic cavity when these nodes more commonly displace structures in the neck. However, it does illustrate a key diagnostic pearl of thyroid cancer which is that it is best diagnosed using a dedicated thyroid ultrasound; CT or MRI of the neck is not the optimal imaging modality for examining thyroid tissue and a negative scan should not be used to rule out thyroid disease. Interestingly, this patient had this mass for several decades and thus his thyroid disease may have progressed after the cyst was already present.
Authors
Camille Yongue (1), Michael Dorsey (2), Arianna Winchester (3), Michael Persky (3), Xiaoqing O'Leary (4), Amie Kent (3)
Institutions
(1) NYU Langone Medical Center, NY, (2) NYU Langone Health, New York, NY, (3) NYU Langone Health, New York, NY, (4) NYCHHC Bellevue, New York, NY
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Category
Thoracic