Prognosis of thyroid nodules in individuals living in the Zhitomir region of Ukraine.

OBJECTIVE: After the accident at the Chernobyl Nuclear Power Plant (CNPP), the incidence of thyroid cancer increased among children. Recently, a strong relationship between solid thyroid nodules and the incidence of thyroid cancer was shown in atomic bomb survivors. To assess the prognosis of benign thyroid nodules in individuals living in the Zhitomir region of Ukraine, around the CNPP, we conducted a follow-up investigation of screening data from 1991 to 2000 in the Ukraine. PATIENTS AND METHODS: Participants of this study were 160 inhabitants with thyroid nodules (nodule group) and 160 inhabitants without thyroid nodules (normal control group) intially identified by ultrasonography from 1991 to 2000. All participants were aged 0 to 10 years old and lived in the same area at the time of the accident. We performed follow-up screening of participants and assessed thyroid nodules by fine needle aspiration biopsy. RESULTS: Among the nodule group participants, the number and size of nodules were significantly increased at the follow-up screening compared with the initial screening. No thyroid nodules were observed among the normal control group participants. The prevalence of thyroid abnormality, especially nodules that could be cancerous (malignant or suspicious by fine needle aspiration biopsy), was 7.5% in the nodule group and 0% in the normal control group (P<0.001). CONCLUSIONS: Our study indicated that a thyroid nodule in childhood is a prognostic factor associated with an increase in the number and size of nodules in individuals living in the Zhitomir region of Ukraine.

Cytopathologic features of secondary peripheral ameloblastic carcinoma: a case report.

Peripheral ameloblastic carcinoma is an extremely rare odontogenic tumor derived from the remnants of dental lamina and/or mucosal epithelium of the oral mucosa. We present a case of secondary peripheral ameloblastic carcinoma of the mandibular gingiva. The patient was a 71-year-old man with gingival swelling and persistent bleeding. Exfoliative cytology revealed cohesive clusters composed of basaloid cells with nuclear atypia and various forms of keratinized cells of dysplastic squamous appearance. Some cell groups had a peripheral palisade. Histology of the biopsy and surgically removed specimens revealed characteristic features resembling squamous cell carcinoma, basal cell carcinoma, and benign follicles of ameloblastoma. These neoplastic structures, as well as proliferation and elongation of the mucosal epithelium, comprised an extensive network. The varied cytopathologic findings may be related to proliferation and transformation of basal cells of the mucosal epithelium toward ameloblastic carcinoma and variable squamous differentiation.

Stepwise progression from ground-glass opacity towards invasive adenocarcinoma: long-term follow-up of radiological findings.

The natural history of lung adenocarcinoma with ground-glass opacity (GGO) remains undetermined. We describe a lung adenocarcinoma in which GGO transformed through a scar-like lesion over the long term into a solid nodule of poorly differentiated adenocarcinoma. Whether poorly differentiated lung adenocarcinoma can evolve from GGO-type adenocarcinoma is an important issue that requires clarification.

Hyperplastic polyposis associated with two asynchronous colon cancers.

We report a patient with hyperplastic polyposis who had two asynchronous colon cancers, a combined adenoma-hyperplastic polyp, a serrated adenoma, and tubular adenomas. Hyperplastic polyposis is thought to be a precancerous lesion; and adenocarcinoma arises from hyperplastic polyposis through the hyperplastic polyp-adenoma-carcinoma sequence. Most polyps in patients with hyperplastic polyposis present as bland-looking hyperplastic polyps, which are regarded as non-neoplastic lesions; however, the risk of malignancy should not be underestimated. In patients with multiple hyperplastic polyps, hyperplastic polyposis should be identified and followed up carefully in order to detect malignant transformation in the early stage.

Clinical implications of pre-operative rapid BRAF analysis for papillary thyroid cancer.

The activating point mutation of the BRAF gene, BRAF(T1799A), is the most common and specific genetic alteration in adult papillary thyroid carcinoma (PTC) and a possible marker of malignant potential of PTC. We have applied the PCR-RFLP method using fine-needle aspiration biopsy samples not only to our clinical practice but also to the international medical assistance effort around the Semipalatinsk Nuclear Testing Site in Kazakhstan. Seventy-seven cases (100 nodules) from Japan and 131 cases (137 nodules) from Kazakhstan were examined. There were 14 Japanese and 76 Kazakhstani cases of cytological malignant tumors from the examined samples. We detected 12 (85.7% of PTC) and 19 (25% of PTC) cases with BRAF(T1799A) among the Japanese and Kazakhstani cases, respectively. Of these cases, we found mutations in one cytologically "suspicious" case and even in two pathologically "benign" cases (after surgery in Kazakhstan). All of the BRAF mutation-positive cases, including those three, were confirmed as PTC by careful pathological examination, including immunohistochemical analysis. In summary, our PCR-RFLP method for BRAF(T1799A) detection using FNAB samples is useful not only for preoperative diagnosis of PTC but also as a complementary diagnostic tool for accurate pathological diagnosis, even after surgery.

Contrast-enhanced dynamic magnetic resonance imaging of primary pulmonary leiomyosarcoma.

An abnormal opacity was found incidentally on chest radiography in a 19-year-old Japanese man with lumbago. Chest computed tomography (CT) revealed a 55 x 40 mm well-defined mass with smooth margins in the lower lobe of the right lung (S6). Contrast-enhanced dynamic CT showed that the lesion was not enhanced, suggesting a cystic lesion, such as a bronchogenic cyst. However, contrast-enhanced dynamic magnetic resonance imaging (MRI) revealed enhancement of the lesion, which had a clear margin and homogenous consistency, suggesting a benign pulmonary solid tumor. Video-assisted thoracoscopic surgery, S6 segmentectomy, was performed, disclosing the lesion to be solid. Histopathologically, the tumor consists of spindle cells with ample eosinophilic cytoplasm arranged in an interlacing pattern. Immunohistochemical staining revealed positive desmin reactivity but was negative for alpha smooth muscle actin and HHF-35 (muscle specific actin), indicating atypical phenotypic differentiation. The lesion was accordingly diagnosed as leiomyosarcoma with low grade malignancy, and right lower lobectomy was performed. The patient has remained free from recurrence for 18 months without any additional chemotherapy or radiation therapy. Contrast-enhanced dynamic MRI should be carried out to facilitate accurate preoperative diagnosis and selection of the correct surgical plan.

Better choice of fixatives provides better histological details of the alveolar-capillary interface.

AIMS: To evaluate lung disease, pulmonary tissues should be fixed by inflation. However, many histological sections prepared after inflation fixation show wire-like alveolar septa with capillary collapse. We investigated the reason for this artefact. METHODS: To evaluate the effect of fixatives, we used the following commercially available solutions: regular 10% neutral buffered formalin (NBF), 20% NBF, 10% and 5% formalin prepared by diluting the 20% NBF, modified formalin solution as a substitute for 10% NBF, and 10% formalin prepared by diluting the 100% formalin without any buffers. RESULTS: The osmolarity of the fixative was found to be responsible for the collapse artefact. Ten per cent formalin, prepared by diluting 100% formalin, the commercially available substitute for 10% NBF, and 5% formalin prepared by diluting 20% NBF, yielded the best pulmonary tissue morphology, including that of the alveolar-capillary interface. CONCLUSIONS: Pulmonary physicians and pulmonary pathologists should use a suitable fixative solution for obtaining a better pulmonary architecture as well as to preserve the tissue block in optimal condition for future assessment of pulmonary diseases.

A case of mucoepidermoid carcinoma with melanin pigmentation manifested in the palate.

This paper describes the first documented case of mucoepidermoid carcinoma (MEC) with melanin pigmentation manifested in the palate. Histopathological sections showed a neoplasm composed of epidermoid, mucous-producing and intermediate cells. Numerous large cells contained dark pigmented materials. Fontana Masson staining revealed dendritic melanocytes and melanin granules. HMB-45, Melan A and S-100 protein were all positive for melanocytes. Histopathological examination was not typical for malignant melanoma; the lesion was diagnosed as a low-grade MEC with melanin pigmentation.

A novel plasmacytoid dendritic cell line, CAL-1, established from a patient with blastic natural killer cell lymphoma.

Blastic natural killer (NK) cell lymphoma corresponding to CD4+CD56+ malignancies is a novel disease entity, according to the results of clinical, morphologic, and immunologic studies. It is especially noteworthy that this disease likely arises from plasmacytoid dendritic cells (pDCs), described previously as plasmacytoid T-cells, which have an important role in innate and adaptive immunity. However, the exact relationship between the tumor cells and pDCs remains to be elucidated. We encountered a patient with typical blastic NK cell lymphoma, which later converted to leukemic manifestations, and tried to establish a cell line using the leukemic cells. We succeeded in establishment of a novel cell line, CAL-1, which originated from the primary malignant cells. The genetic and phenotypic features of CAL-1 cells bear a similarity to those of pDCs, namely, plasmacytoid morphology at light and electron microscopy; negative results for CD11c and lineage-associated markers of CD3, CD14, CD19, and CD16; positive results for HLA-DR, CD4, CD56, CD45RA, and CD123; and negative results for TCR and IgH gene rearrangements. An interesting finding was that CAL-1 cells change morphologically into the mature DC appearance with many long dendrites after short-term culture in the presence of granulocyte-macrophage colony-stimulating factor and interleukin 3. CAL-1 cells can secrete tumor necrosis factor alpha but not interferon alpha. Thus although they do not share in part phenotypic and functional features with their normal counterparts, CAL-1 cells mostly exhibit a striking pDC phenotype. We describe the first novel pDC cell line of CAL-1. This cell line should open the opportunity for study not only of CD4+CD56+ tumor cells but also of pDCs in vitro.