Outcome and diagnostic reproducibility of the thyroid cytology "indeterminate categories" SIAPEC/SIE 2014 in a consecutive series of 302 cases.

PURPOSE: The clinical impact of the SIAPEC/SIE 2014 classification for thyroid cytology has been addressed in few studies that evaluated the malignancy rate and the relative prevalence of each category. No study analyzed its intra-observer and inter-observer reproducibility, so far. METHODS: We retrospectively collected all "indeterminate" lesions diagnosed before (2011-2014) and after (2015-2018) the application of the SIAPEC/SIE 2014 classification at our Institution. Their relative malignancy risks were calculated based on available histological diagnoses. Cytological and clinical features of TIR3A were compared with the surgical outcome. Finally, a large set of samples was re-evaluated in blind of the original cytological and histological diagnoses by two pathologists, independently. RESULTS: The prevalence of "indeterminate" diagnoses increased in years 2015-2018 (302/1482, 21% with 14% of TIR3A and 7% TIR3B categories) compared to years 2011-2014 (261/1680, 16%). Surgery was performed in 27% TIR3A and in 97% TIR3B cases. Malignancy rates were 40% for TIR3B and 17% for TIR3A, but were greatly influenced by the adoption of the WHO 2017 re-classification of encapsulated follicular-patterned lesions (decreasing to 28% and 6%, respectively). No criteria except for tumor size were associated to malignancy in TIR3A category. Intra-observer agreement of the experienced pathologist was 122/141 (86%), whereas inter-observer agreement between the expert and in-training pathologist was 95/141 (67%). CONCLUSIONS: In this real-life experience, the sub-classification of TIR3A and TIR3B slightly increased the overall prevalence of "indeterminate" diagnoses. Malignancy rates were higher than estimated for both TIR3A and TIR3B categories. Agreement among observers highly depended on pathologist's training.

Hyalinizing trabecular tumor of the thyroid: a case report.

Hyalinizing trabecular tumor (HTT) of the thyroid is a rare neoplasm that was first described by Carney in 1987. It is a tumor of follicular derivation with peculiar nuclear, architectural, histochemical, and immunohistochemical features. We report a case of HTT in a 69-year-old woman with a mutinodular goiter. Since the clinical and ultrasonographic features were nonspecific, fine needle aspiration biopsy (FNAB) of the left lobe-dominant node was performed that resulted in an indeterminate cytologic diagnosis (category THY-3). The patient underwent total thyroidectomy, with a histologic diagnosis of HTT. We discuss the clinical and diagnostic approach, including the role of FNAB, and the pathologic features of HTT with special reference to the possible differential diagnosis. Total thyroidectomy or hemithyroidectomy represent adequate treatments, while radioiodine ablation is not standard. Although rare cases of malignant HTT have been documented, this tumor should be considered a benign neoplasm or, at most, a neoplasm of extremely low malignant potential. As a consequence, once this diagnosis is rendered, clinical management should be conservative, which may include a precautionary annual follow-up in order to exclude the very rare possibility of recurrence, as exceptionally reported.

Acromegaly due to ectopic secretion of GHRH by bronchial carcinoid in a patient with empty sella.

GH hyperproduction due to ectopic secretion of GHRH is a rare cause of acromegaly. Since 1959, approximately 50 cases of ectopic GHRH production from extrapituitary tumors have been described. Here we report the clinical and biochemical features of a 47-yr-old Caucasian woman with ectopic GHRH syndrome sustained by a bronchial carcinoid. The criteria for the diagnosis of acromegaly due to ectopic GHRH secretion were satisfied in our patient (i.e. confirmation of active GH hypersecretion, unequivocal demonstration of GHRH production and secretion from an extrapituitary tumor and cure of acromegaly after neoplasm removal). The tumor was an atypical carcinoid and there was a familial history of lung and colorectal cancer. Acromegaly was slightly active (mean GH value: 7.4 ng/ml, IGF-I: 436 ng/ml) and after tumor removal there was a progressive decline of GH levels, consistent with remission of pituitary somatotroph hyperplasia. Pituitary radiology showed an empty sella demonstrating for the first time its association with ectopic GHRH syndrome.

Role of fine-needle aspiration biopsy and frozen-section evaluation in the surgical management of thyroid nodules.

BACKGROUND: The role of routine frozen section (FS) in the surgical management of thyroid nodules remains uncertain. This study reviewed the role of FS in the presence of an adequate fine-needle aspiration biopsy (FNAB). METHODS: FNAB and FS were evaluated in 206 patients who had surgery for a thyroid nodule. Cytological specimens were classified as benign, malignant or suspicious. The FS diagnoses were benign, malignant or deferred. RESULTS: A cytological diagnosis was obtained in 93 nodules; the remaining 113 were classified as suspicious, of which 21 were malignant on definitive examination. The overall accuracy of FNAB was 53 per cent. FS evaluation identified 165 lesions as benign; the diagnosis was deferred until definitive histological evaluation in only eight. The overall accuracy, therefore, was 96 per cent. Routine use of FS was cost-effective; lowering the number of reoperations led to an estimated saving of about 40 per cent. CONCLUSION: These data suggest that FS remains an important tool in the surgical management of thyroid nodules and can reduce the number of patients requiring reoperation.

Galectin-3 as a presurgical immunocytodiagnostic marker of minimally invasive follicular thyroid carcinoma.

Thyroid nodules are a common occurrence in the general population, but only a small number of them are eventually diagnosed as cancers. Fine-needle aspiration biopsy (FNAB) is the most accurate and cost-effective method for the presurgical management of thyroid nodules, but it misses the differential diagnosis between thyroid follicular adenomas and follicular carcinomas. Among them, minimally invasive follicular carcinoma (MIC), also defined as encapsulated tumor, only differs from follicular adenoma for the exhibition of minimal, but entire thickness, infiltration of the capsule and/or vascular invasion. This feature cannot be assessed in FNAB and can occasionally be hard to recognize in surgical specimens. As reported in several studies, galectin-3 is a reliable marker of thyroid malignancy, but no data are available on MICs. We analyzed the immunohistochemical expression of galectin-3 in 17 MICs and 52 follicular adenomas in both preoperative paraffin-embedded cytological human thyroid sediments (cell blocks) obtained by FNAB and in the corresponding surgical specimens. Among the MICs, all surgical samples showed galectin-3 immunoreactivity in the cytoplasm, whereas 16 of 17 corresponding FNAB cell blocks were positive. No evidence of cytoplasmic galectin-3 expression was observed in 48 of 52 adenomas in both cell blocks and histological tissues. These findings indicate that galectin-3 is a reliable presurgical molecular marker of MIC, improving the accuracy of conventional FNAB. It also proves to be useful in the histopathological assessment of resected tumors having suspected malignant features.

Treatment of medullary thyroid carcinoma: an update.

Prognosis and treatment effectiveness of medullary thyroid carcinoma (MTC) are largely related to the tumour stage, so that early diagnosis represents an important goal for the management of patients. Recent advances in genetic testing have improved the clinical approach to the familial MTC syndromes. There is general agreement that the primary operation for MTC should obtain the complete removal of the neoplastic tissue in the neck, because any adjuvant treatment has never been proven to be effective. The management of residual/recurrent or metastatic MTC still remains controversial, although a multimodal approach to advanced disease may be of value in palliation or local control of tumour progression. The role of surgery, external radiotherapy, radionuclide therapy and medical treatment, including biological response modifiers and cytotoxic drugs, are reviewed and discussed.

RET proto-oncogene mutation in a mixed medullary-follicular thyroid carcinoma.

A case of a patient with an uncommon thyroid carcinoma, showing histological and immunohistochemical features of both follicular and parafollicular cells is described. Somatic point mutation (ATG to ACG heterozygotic mutation at codon 918) of the RET proto-oncogene was detected in tumor tissue, as confirmed by immunohistochemical expression of RET oncoprotein. Our findings suggest that constitutive RET proto-oncogene activation may be involved in the development of mixed medullary-follicular thyroid carcinoma.

Chemotherapy with dacarbazine and 5-fluorouracil in advanced medullary thyroid cancer.

BACKGROUND: Experience with chemotherapeutic agents in the management of advanced medullary thyroid carcinoma (MTC) is limited and controversial. However, since MTC is a neuroendocrine neoplasm, we considered the possibility that cytotoxic drugs previously used in the treatment of these tumours could also have activity in MTC. PATIENTS AND METHODS: Five patients (4 females and 1 male, aged 22-71 years) with locally advanced or metastatic MTC received 5 day intravenous courses of dacarbazine (DTIC) (250 mg/sqm) and 12 hour infusion 5-fluorouracil (450 mg/sqm), given every 4 weeks. Six cycles were administered to 4 patients and four to 1 patient. RESULTS: Three partial responses lasting 9, 10+ and 8+ months were observed; one patient had stable disease and one progressive disease. Toxicity was acceptable with grade I thrombocytopenia and grade II leukopenia occurring in one patient, and grade II nausea and vomiting in four patients. CONCLUSIONS: In our experience, treatment of advanced thyroid carcinoma with DTIC and 5-FU appeared to have significant activity and was well tolerated.

Steroid biochemistry and categorization of breast cyst fluid: relation to breast cancer risk.

Patients bearing macrocysts of the breast are at higher risk of later developing cancer. The fluid filling the cysts (breast cysts fluid, BCF) contains unusual amounts of steroid conjugates, first androgen and estrogen sulfates. Measuring BCF cations (K+,Na+) allows categorization of cysts into two major subsets (type I and type II) that are associated with a different degree and/or turnover of apocrine metaplastic cells in the lining epithelium. Type I cysts (high K+/Na+ ratio) accumulate hugh amounts of dehydroepiandrosterone sulfate, estrone sulfate, androstane-3 alpha,17 beta-diol glucuronide, androsterone glucuronide and contain more testosterone and dihydrotestosterone than type II. Conversely, type II cysts (low K+/Na+ ratio) contain more progesterone and pregnenolone. A cohort study was started in 1983 at the Cancer Prevention Center, Ravenna, Italy, with the aim of evaluating the relationships between the biochemistry of BCF and the incidence of breast cancer in women with gross cystic disease (GCD) of the breast. The bimodal distribution of the cationic pattern has been confirmed from data obtained in 798 patients aspirated. The risk of cyst relapse was significantly higher among women with type I cysts or with multiple cysts at presentation. Twelve incident cases of breast cancer have been diagnosed among women whose BCF was categorized. Eleven out of 12 cases had type I or multiple cysts. The cumulative incidence of breast cancer among patients bearing type I cysts was 2.5%. We conclude that women with GCD bearing type I cysts have an increased breast cancer risk when compared with the counterpart bearing type II cysts or the general population.

Categorization of cysts and steroid levels in breast cyst fluid.

Several reports indicate that patients with macrocysts have a two- to fourfold higher risk of developing cancer. The fluid filling the cysts (breast cyst fluid, BCF) contains unusual amounts of biologically active substances, including hormones and metabolites. The accumulation of steroid conjugates, such as androgen and estrogen sulfates, deserves interest. Measuring BCF cations (K+, Na+) permits classification of cysts into two major subsets (type I and type II), conceivably associated with a different degree and with a turnover of apocrine cells in the lining epithelium. Type I (high K+/Na+ ratio) and type II (low K+/Na+ ratio) cysts display different patterns of steroid analytes and steroid-binding proteins. There are many gaps in our understanding of the relationship between local steroids and hypersecretion of fluid in the terminal duct lobular units with eventual appearance of cysts. Accumulating biochemical and epidemiological data, however, point to recurrent, multiple type I cysts as a marker of endocrine risk, i.e., of a whole-organ promoting status toward proliferative premalignant lesions.