Surgical indications for upper mediastinal dissection by sternotomy in patients with papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is a relatively indolent disease, despite the high incidence of lymph node metastases. Although less frequent, some upper mediastinal metastases of PTC cannot be removed without sternal resection. In this study, we investigated the prognostic impact of upper mediastinal dissection (UMD) by sternotomy on patients with mediastinal metastases of PTC. Charts of patients with PTC who underwent surgical treatment at our institution between 2006 and 2018 were retrospectively reviewed. Fifty-eight patients with upper mediastinal metastases were enrolled. Kaplan-Meier survival curves were compared, and Cox hazard regression models were used for analyses. Of the 58 patients with mediastinal metastasis, 12 (20.7%) underwent dissection of the prevascular nodes, 51 (87.9%) underwent dissection of the upper paratracheal nodes, and 14 (24.1%) underwent dissection of the lower paratracheal node. The preferred site of mediastinal metastasis was the upper paratracheal nodes. The 5 and 10-year disease-specific survival rates for patients after UMD were 74.6% and 58.7%, respectively. Among 25 patients (43.1%) with locoregional recurrence, 12 (20.7%) had mediastinal recurrence and 7 were eligible for additional UMD. Although distant metastasis was the predominant poor prognostic factor, mediastinal recurrences were more frequently unresectable than cervical recurrences, suggesting that mediastinal recurrence is a poor prognostic factor. Mediastinal metastases larger than 30 mm or metastases to the lower paratracheal nodes are considered a risk factor for mediastinal recurrence. UMD by sternotomy for patient with upper mediastinal metastases which are difficult to resect via transcervical approach is an effective treatment option to improve patient prognosis.

Novel surgical methods for reconstruction of the recurrent laryngeal nerve: Microscope-guided partial layer resection and intralaryngeal reconstruction of the recurrent laryngeal nerve

BACKGROUND

The optimal strategy for surgical management of papillary thyroid carcinoma invasion of the recurrent laryngeal nerve remains controversial. Our aim was to evaluate the efficacy of 2 surgical methods and provide detailed descriptions of microscope-guided partial layer resection and intralaryngeal reconstruction of the recurrent laryngeal nerve.

METHODS

This retrospective study enrolled 85 patients with papillary thyroid carcinoma who underwent initial surgical excision for invasion of the recurrent laryngeal nerve. Twenty-seven patients (28 recurrent laryngeal nerve sites) underwent partial layer resection, and 11 patients (11 recurrent laryngeal nerve sites) underwent intralaryngeal reconstruction of the recurrent laryngeal nerve. The remaining patients underwent either only resection or resection with immediate reconstruction of the recurrent laryngeal nerve. Pre and postoperative phonetic function and rates of locoregional recurrence were extracted from medical charts for analysis.

RESULTS

Isolated locoregional recurrence specific to the aerodigestive tract was identified in 1 patient (3.7%) in the partial layer resection group and 1 patient (9.1%) in the intralaryngeal reconstruction group. Seventy-five percent of patients in the partial layer resection group recovered or had preserved vocal cord function, and the mean maximum phonation time of the patients with postoperative complete vocal cord palsy was 15.3 seconds. The mean maximum phonation time of the patients, excluding 4 patients with permanent stoma in the intralaryngeal reconstruction group, was 22.3 seconds. The mean maximum phonation time of either group was longer than that of patients with recurrent laryngeal nerve resection only and comparable with that of patients with recurrent laryngeal nerve resection and immediate reconstruction.

CONCLUSION

Patients who underwent either partial layer resection or intralaryngeal reconstruction had low rates of locoregional recurrence specific to the aerodigestive tract and good postoperative functional outcomes.

Parathyroid carcinoma coexisting with multiple parathyroid adenomas: a case report

Primary hyperparathyroidism is usually caused by parathyroid adenoma; however, parathyroid carcinoma is a rare cause. We report a rare case of 74-year-old female of primary hyperparathyroidism caused by parathyroid carcinoma (PC) and coexisting multiple parathyroid adenomas. She was referred to our hospital for primary hyperparathyroidism and a suspected thyroid tumor. She had no family history of malignant tumor. Computed tomography (CT) and ultrasonography of the neck revealed some masses posterior to both thyroid lobes. Those masses were believed to be parathyroid lesions. However, another mass located posterior to the right upper thyroid lobe seemed to be heterogeneous, which indicated a malignant thyroid tumor as well as parathyroid tumor. The preoperative diagnosis was multiple parathyroid adenoma and suspicious incidental thyroid carcinoma. Therefore, the patient underwent total parathyroidectomy and thyroidectomy. The histopathological diagnosis was parathyroid carcinoma coexisting with multiple parathyroid adenomas. There was no evidence of recurrence at 1 year after the surgery. It was difficult to diagnose PC preoperatively. Few rare cases of PC coexisting with parathyroid adenoma in multiple endocrine neoplasia type 1 (MEN1) have been reported. Therefore, careful follow-up was necessary considering the possibility of MEN1, though she did not wish for a genetic examination.

A case report of thyroid metastasis from p16-positive oropharyngeal squamous cell carcinoma

Thyroid metastasis from head and neck squamous cell carcinoma (SCC) is a very rare form of rarely observed metastatic thyroid tumor. We herein report a case of thyroid metastasis from oropharyngeal SCC (OSCC). The patient was a 68-year-old male diagnosed with p16-positive tonsillar OSCC on the right side with multiple lymph node metastases and a thyroid mass, which was determined as metastatic p16-positive OSCC by immunohistochemistry of specimens collected by fine-needle aspiration cytology (FNAC). He received one cycle of induction chemotherapy followed by concurrent chemoradiotherapy. No visible primary lesions were observed after treatment. The disappearance of the tonsillar lesion was considered to be a complete response by the magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT). The thyroid lesion was also decreased, but a solid lesion with unclear boundaries in the right thyroid lobe remained. Therefore, the patient underwent total thyroidectomy to remove any residual tumor. Postoperative pathological evaluation revealed no residual viable carcinoma cells in the resected specimen. As illustrated in this case, immunohistochemistry of the FNAC specimen for p16 was successful in determining the thyroid tumor as a metastatic lesion from the oropharynx. Although radical radiotherapy might be sufficient to control thyroid gland metastasis of OSCC, in this case, early-stage remedial surgery was thought to be necessary for a secure radical cure.

Thyrolipomatosis: A case report with review of the literature

Fatty tissue is not usually present within the thyroid gland. Only a few fat-containing thyroid lesions have been reported to date, and thyrolipoma is the most common fat-containing lesion of the thyroid gland. Thyrolipomatosis is a condition characterized by diffuse mature adipose cell infiltration of the normal thyroid gland. In this report, we describe what is, to the best of our knowledge, the 12th documented case of thyrolipomatosis, and review the fat-containing lesions of the thyroid gland. A 68-year-old Japanese woman presented with a neck mass that had first been noticed ~7 years earlier. A computed tomography scan revealed diffuse thyroid gland enlargement and total thyroidectomy was performed. The histopathological examination revealed that mature fatty tissue was diffusely distributed throughout the thyroid gland, as well as among the hyperplastic follicles. Capsular formation or amyloid deposition were not observed. Nuclear grooves or intranuclear cytoplasmic inclusions were not observed. Accordingly, thyrolipomatosis was diagnosed. Albeit rare, various neoplastic and non-neoplastic thyroid lesions may contain mature fatty tissue. Therefore, thyrolipomatosis must be included in the differential diagnostic consideration of fat-containing lesions of the thyroid gland.

PITX1 is a novel predictor of the response to chemotherapy in head and neck squamous cell carcinoma

The pituitary homeobox 1 (PITX1) protein is essential for developmental processes in humans. Previously, PITX1 was identified as a possible tumor suppressor gene in various types of human carcinoma. However, the association between PITX1 and human head and neck squamous cell carcinoma (HNSCC) remains to be elucidated. Immunohistochemical analysis was performed to examine the expression levels of PITX1 in 47 cases of HNSCC, and in 4 control cases. The expression of p53 was also examined in these cases. The labeling indices (LIs) were calculated, and the correlations between clinical factors (chemosensitivity, prognosis and the degree of differentiation) and the LIs were assessed. The PITX1 LI in HNSCC was 27.4±14.5%, which was significantly lower compared with the LIs of the control samples: 76.9±6.97% (P<0.05). Additionally, the PITX1 LIs were 39.9±6.2, 26.9±16.9 and 24.2±11.8% in the complete response (CR), partial response (PR), stable disease or progressive disease (SD/PD) groups, respectively. The PITX1 LI in the CR group revealed the highest result between the all groups, and it was significantly greater compared with that in the SD/PD group (P<0.01). The p53 LIs were 24.5±19.9, 25.7±16.9 and 19.8±13.8 in the CR, PR and SD/PD groups, respectively (P>0.05). Neither the PITX1 nor the p53 LIs were a statistically significant indicator of the prognosis. PITX1 is a candidate tumor suppressor gene and a possible predictive biomarker of chemosensitivity of human HNSCC.

Correlation between quantitative shear wave elastography and pathologic structures of thyroid lesions

The aim of this study was to determine the correlation between shear wave velocity (SWV) generated by acoustic radiation force impulse and the pathologic structure of thyroid lesions. A total of 599 thyroid tissue samples were divided into four groups based on pathologic structure: 254 normal thyroid tissue samples as a control, 128 with chronic autoimmune thyroiditis (CAT) that demonstrated diffuse fibrosis, 165 with benign nodules that had high cell density and 52 with papillary thyroid carcinoma (PTC) that showed high cell density and fibrosis. The mean SWVs in each group were as follows: 1.60 ± 0.18 m/s in normal thyroid, 2.55 ± 0.28 m/s in CAT, 1.72 ± 0.31 m/s in benign nodules and 2.66 ± 0.95 m/s in PTC. The SWVs of CAT and PTC were significantly higher than those of normal thyroid, (p < 0.001). SWV was significantly affected by fibrosis.