Cytopathological review of patients that underwent thyroidectomies based on the diagnosis of papillary thyroid carcinoma by fine needle aspiration cytology but were later found to have benign tumors by histopathology.

PURPOSE: The aim of this study is to evaluate the specificity of diagnosing PTC by fine needle aspiration (FNA) cytology. METHODS: This study retrospectively reviewed the cytopathological reports of 1066 patients that underwent thyroidectomy based on a diagnosis of PTC by FNA between January 1993 and December 2008. This study re-evaluated the cytology and histopathology of the patients that received false positive diagnoses of PTC by FNA. RESULTS: Ten patients (0.9 %) received false positive diagnoses of PTC by FNA. Three patients were overdiagnosed as having PTC by FNA cytology. In contrast, the nuclear features of PTC in the other seven cases were confirmed by the retrospective reviews of the patients' FNA cytology. Three of the seven patients showed follicular structures in their resection specimens, thus resulting in a diagnosis of either adenomatous goiter or follicular adenoma. However, PTC could not be diagnosed by histopathology in the remaining four patients, even though the histopathology showed the nuclear features of PTC. CONCLUSIONS: Most cases of PTC can be easily diagnosed by cytological and morphological atypia with certain limitations. The difficulty in diagnosing PTC by cytology is because the pathological features of PTC also occur in some benign thyroid tumors. Therefore, immunohistochemical or molecular biological approaches must be combined with current cytological diagnostic techniques for the diagnosis of PTC.

Three distinctly different kinds of papillary thyroid microcarcinoma should be recognized: our treatment strategies and outcomes.

BACKGROUND: Papillary microcarcinoma (PMC) of the thyroid generally follows a benign clinical course. However, treatment strategies remain controversial. According to our previous retrospective review of 178 patients with PMC who underwent surgery between 1976 and 1993, the most significant risk factors affecting cancer-specific survival were clinical symptoms at presentation due to invasion or metastasis. Distant metastasis and cancer-specific death were never seen postoperatively for 148 cases (83%) of asymptomatic PMC without clinically apparent (>or=1 cm) lymph node metastasis or recurrent nerve palsy. Based on these results, we identified three biologically different types of PMC that should be treated differently. Type I comprises incidentally detected PMC without any symptoms, which is harmless and the lowest-risk cancer. Conservative follow-up with ultrasonography every 6 or 12 months is feasible. Type II involves the early stage of the usual low-risk papillary carcinoma. This can be treated by lobectomy when increasing size is noted during conservative follow-up. Type III comprises clinically symptomatic PMC, representing a high-risk cancer. Immediate wider resection followed by radioiodine treatment and suppression of thyroid-stimulating hormone is recommended. METHODS: Since 1995, we have been conducting a prospective clinical trial of nonsurgical observation for asymptomatic PMC. As of 2008, 230 of 244 candidates (94%) have decided to accept this policy, whereas 56 patients underwent surgery for symptomatic PMC between 1976 and 2006. RESULTS: Nonsurgical observation for a mean of 5 (range, 1-17) years for 300 lesions of asymptomatic PMC revealed that 22 (7%) had increased in size, 269 (90%) were unchanged, and 9 (3%) had decreased. No patients developed extrathyroidal invasion or distant metastasis. Three patients (1%) who developed apparent lymph node metastasis and nine patients (4%) in whom tumor increased in size eventually received surgery after 1-12 years of follow-up. No recurrences have been identified postoperatively. Conversely, 10-year cause-specific survival for symptomatic PMC was 80%. Multivariate analysis identified extrathyroidal invasion, large lymph node metastasis (>or=2 cm), and poorly differentiated component as significantly related to adverse outcomes. CONCLUSIONS: Nonsurgical observation seems to represent an attractive alternative to surgery for asymptomatic PMC. Almost 95% of asymptomatic PMC patients are type I, and another 5% are type II and can be treated with conservative surgery. A small number of PMCs with bulky lymph node metastasis or extrathyroidal invasion are high-risk type III and require aggressive treatment.

Frozen section is superior to imprint cytology for the intra-operative assessment of sentinel lymph node metastasis in stage I breast cancer patients.

BACKGROUND: A standard intra-operative procedure for assessing sentinel lymph node metastasis in breast cancer patients has not yet been established. PATIENTS AND METHODS: One hundred and thirty-eight patients with stage I breast cancer who underwent sentinel node biopsy using both imprint cytology and frozen section were analyzed. RESULTS: Seventeen of the 138 patients had sentinel node involvement. Results of imprint cytology included nine false negative cases (sensitivity, 47.1%). In contrast, only two cases of false negatives were found on frozen section (sensitivity, 88.2%). There were two false positive cases identified by imprint cytology (specificity, 98.3%). On the other hand, frozen section had 100% specificity. CONCLUSION: These findings suggest that frozen section is superior to imprint cytology for the intra-operative determination of sentinel lymph node metastasis in stage I breast cancer patients.

Endoscopic classification of intraductal lesions and histological diagnosis.

BACKGROUND: To diagnose intraductal lesions endoscopically the Japanese Association of Mammary Ductoscopy classified the endoscopical appearance of lesions into three types. We investigated the correlation between endoscopic classification and histological diagnosis. METHODS: From April 1998 to February 2001, we enrolled 129 female patients who were diagnosed histologically and whose intraductal lesions were detected by mammary ductoscopy. The endoscopic classification consists of three types. The polypoid type is a localized expansive lesion. This type is divided into two subtypes, the solitary subtype (solitary polypoid lesion) and the multiple subtype (multiple polypoid lesions). The combined type is polypoid lesion(s)coexisting with a superficial type. The superficial type is a superficial spreading lesion such as a continuous luminal irregularity accompanied by no obvious elevations. RESULTS: There were 65 cases of breast cancer and 64 cases of benign papillary lesions. Fifty-four cases of benign papillary lesions and 7 cases of breast cancer were classified as the polypoid-solitary type. Seven benign cases and 13 cases of cancer were classified as the polypoid-multiple type. Two benign cases and 16 cases of cancer were classified as the combined type. Only one benign case and 29 cases of cancer were classified as the superficial type. There is significant correlation between endoscopical types and the histological diagnosis (p<0.0001). CONCLUSIONS: Endoscopic classification is useful to diagnose intraductal lesions.

Muco-epidermoid carcinoma of the breast.

A very rare case of muco-epidermoid carcinoma of the breast is reported. A 54-year-old woman noticed a breast lump and consulted the Cancer Institute Hospital, Tokyo. Physical examination revealed a mass with an unclear margin in the upper outer area of the left breast. Both mammography and ultrasonography showed an irregularly shaped mass, suggesting invasive carcinoma. Aspiration cytology revealed solid clusters of two types of cancer cells: ones with mucus in the cytoplasm, and others without mucus. Cytological features resembled muco-epidermoid carcinoma of the salivary gland but it was not possible to establish a diagnosis of the histological type because muco-epidermoid carcinoma of the breast had not previously been encountered by the authors. After incisional biopsy, left mastectomy with axillary lymph node dissection was performed. Histologically the tumor was surrounded by a fibrous pseudocapsule and was composed of intraductal carcinoma foci and invasive cancer nests. Intraductal carcinoma foci were the low papillary type. Stromal invasion showed many solid nests composed of mucus-containing and squamoid cancer cells. There was no common invasive ductal carcinoma component in this tumor. These histological features confirmed the diagnosis as muco-epidermoid carcinoma of the breast. This is the first report of muco-epidermoid carcinoma of the breast in Japan.

Mucinous cystadenocarcinoma of the breast: a case report and review of the literature.

We report a case of mucinous cystadenocarcinoma (MCA) of the breast in a 96-year-old woman. This is an extremely rare variant of primary breast carcinoma that bears a striking resemblance to MCAs of the ovary and pancreas. The macroscopic appearance and secretion pattern (cytologic findings) resembled cystic hypersecretory carcinoma. However, microscopically, the epithelial cells were quite different from those of cystic hypersecretory carcinoma. In the present study as well as in the literature, MCAs tend to occur more frequently in elderly women. Immunohistochemical findings suggest that they may develop independently of estrogenic stimulation. Although MCAs show high proliferative activity, the prognosis was favorable in the present case as well as in the reported cases. Because MCAs appear to have a distinct pathogenesis and biologic behavior, they should be distinguished from ordinary mucinous carcinomas, cystic hypersecretory carcinomas, and carcinomas of other histologic subtypes.