1/9. A case of spurious hypercalcitoninemia: a cautionary tale on the use of plasma calcitonin assays in the screening of patients with thyroid nodules for neoplasia.The measurement of plasma CT has an important role as a screening test for medullary thyroid carcinoma (MTC) in patients with thyroid nodules. However, elevated plasma CT levels should be interpreted within the context of the overall clinical picture in each individual case and carefully validated before therapeutic decisions are made. We present the case of a 17-yr-old girl who was referred to us with a thyroid nodule and elevated plasma CT levels, as measured by a one-site RIA not involving prior plasma extraction. plasma CT was re-measured using two different methods, a RIA with prior plasma extraction and a two-site immunochemiluminometric assay (ICMA), and was either very low or undetectable. Subsequently, samples were re-assayed using the initially applied CT RIA; plasma CT levels were again found to be elevated. These elevations were of a spurious nature, probably caused by the presence of an unidentified substance in the patient's plasma interfering with the measurement of CT in the initially used RIA. Our patient was eventually diagnosed with Hashimoto's thyroiditis, and had no evidence of MTC. As several conditions can cause either true or spurious hypercalcitoninemia, we suggest that elevated plasma CT levels should be confirmed at least once before other extensive diagnostic investigations are initiated or thyroidectomy is recommended. Finally, the assay selected should detect only the mature CT molecule.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/9. Two cases of medullary thyroid carcinoma.INTRODUCTION: Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy but accounts for a significant mortality. We present 2 cases of MTC and review the literature regarding its management and genetic screening. CLINICAL PICTURE: Patient 1 presented after a routine health screening and subsequently was found to have a germline mutation for men 2A. Patient 2 presented with sweating irritability and a thyroid mass which illustrates the progressive relentless nature of the disease and highlights current imaging practice. TREATMENT: Both patients underwent extensive surgery and received postoperatively ablative dose of radioactive iodine. Patient 2 also had a large dose I-131 MIBG therapy and further surgery. OUTCOME: In Patient 1, postoperative calcitonins remained elevated indicating residual disease. Patient 2 underwent further radioguided surgery; however, his postoperative calcitonins remained elevated. CONCLUSION: MTC can be relentless. Routine genetic screening of all patients with MTC, Tc-99m pentavalent (V) DMSA imaging, near total thyroidectomy with routine central neck dissections and removal of all lymph nodes in the central neck compartment should be performed.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/9. Mixed follicular-medullary thyroid carcinoma: a case report.We report on a 35-yr-old woman presenting with a single thyroid nodule. Fine-needle aspiration (FNA) of the nodule was reported to contain both follicular and parafollicular cells. The biphasic nature of the tumor was highlighted on immunohistochemical investigation of the cellblock. Positive staining for thyroglobulin was limited to the follicular structures and the dense areas stained positive for calcitonin. The serum calcitonin level was highly elevated. Surgery was recommended because of suspected malignancy. The patient underwent total thyroidectomy. The diagnosis of mixed medullary and follicular carcinoma of the thyroid was established by histological investigation using immunohistochemical staining for thyroglobulin, chromogranin, and calcitonin. The patient was well 1 yr after the operation. Repeated measurements of serum calcitonin levels were normal. Total body scan revealed no radioactive iodine uptake in the thyroid bed, bones, or lungs.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
4/9. gene expression profiling of renal medullary carcinoma: potential clinical relevance.BACKGROUND: Renal medullary carcinoma is a rare kidney tumor with highly aggressive behavior. This tumor occurs exclusively in young patients with sickle cell trait or disease. To the authors' knowledge, very little is known to date regarding the underlying molecular genetics of this tumor, and no effective therapy has been established. methods: The authors analyzed the gene expression profiles of 2 renal medullary carcinomas from patients with sickle cell trait using microarrays containing 21,632 cyclic dna (cDNA) clones and compared them with the gene expression profiles of 64 renal tumors. RESULTS: Based on global gene clustering with 3583 selected cDNAs, the authors found a distinct molecular signature of renal medullary carcinoma, which clustered closely with urothelial (transitional cell) carcinoma of the renal pelvis, rather than renal cell carcinoma (RCC). This finding of a significant difference in the gene expression patterns of renal medullary carcinoma compared with RCC suggests that this tumor should not be treated as a conventional RCC but, rather, as a special malignancy. This study also identified genes/proteins that may serve as biomarkers for renal medullary carcinoma or as potential targets of novel therapies. In addition, comparative genomic microarray analysis allowed the authors to predict the lack of chromosomal imbalances in this tumor. CONCLUSIONS: To the authors' knowledge, the current study is the first molecular profiling of renal medullary carcinoma, a rare but highly aggressive kidney carcinoma. The genes that are expressed specifically in this tumor may lead to not only a better understanding of its molecular pathways and discoveries of novel diagnostic markers but also, more important, to effective therapeutic interventions.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
5/9. Lymphoepithelioma-like carcinoma of the breast. Report of a case with the first electron microscopic study and review of the literature.Lymphoepithelioma-like carcinoma (LELC) is a tumor which occurs outside the nasopharynx and has morphological features identical to nasopharyngeal lymphoepithelioma. LELC of the breast (LELC-B) is uncommon, and its resemblance to medullary carcinoma of the breast (MC-B) obscures distinction between these two tumors. We report a case of LELC-B occurring in a 47-year-old woman. The tumor consisted of multinodules without circumscription. The tumor cells mainly exhibited loose clusters being permeated by numerous lymphocytes. The tumor cell clusters showed inconspicuous margins, which were far from syncytial patterns. The epithelial nature of the tumor cells was demonstrated by positivity for epithelial membrane antigen, AE1/AE3 and CAM5.2. Furthermore, glandular differentiation of the tumor cells was confirmed using electron microscopy for the first time. Epstein-Barr virus (EBV) was not detected using either in situ hybridization or polymerase chain reaction. These findings, together with former reports of LELC-B, suggest that the distinction between LELC-B and MC-B depends on whether circumscription and syncytial growth patterns exist. The other findings, including absence of EBV and immunohistochemical aspects of the tumor cells, are not considered different thus far. Although the prognosis of LELC-B is thought to be favorable, which is also similar to MC-B, distant metastasis was detected in the present case. To confirm the clinicopathological entity of these two tumors, it is important to recognize the difference between LELC-B and MC-B.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
6/9. Medullary thyroid carcinoma metastatic to breast masquerading as infiltrating lobular carcinoma.Metastatic tumors to the breast from an extramammary site are rare entities and may present diagnostic difficulties for the surgical pathologist because of frequent histological similarities to primary neoplasms in this location. A case is reported of medullary thyroid carcinoma metastatic to the breast in a 28-year-old woman with a family history of men IIA (Sipple's) syndrome. Histological features resembled infiltrating lobular carcinoma and included the so-called "targetoid" and "Indian file" patterns. Immunostaining revealed the true nature of the lesion and was diffusely positive for calcitonin, chromogranin, and carcinoembryonic antigen. Electron microscopy disclosed typical neurosecretory granules confirming the diagnosis. A brief review of the literature and differential diagnosis is also presented.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
7/9. A case of metastatic medullary thyroid carcinoma: early identification before surgery of an RET proto-oncogene somatic mutation in fine-needle aspirate specimens.Medullary thyroid carcinoma (MTC) management requires determination of the sporadic or familial nature of the disease. RET proto-oncogene mutation analysis in the tumor tissue obtained at surgery and in the peripheral blood identifies somatic vs. germinal mutations. We now report a case of MTC in which a RET somatic mutation at codon 918 was detected in fine-needle aspiration specimens obtained from both the thyroid nodule and two enlarged neck lymph nodes but not in peripheral blood. Therefore, a diagnosis of sporadic MTC was made before surgery. Thus, this approach, by excluding preoperatively multiple endocrine neoplasia disease, permitted immediate thyroidectomy without search for pheochromocytoma. PCR-based genetic analysis in fine-needle aspiration biopsy specimens, therefore, preoperatively identifies genetic abnormalities at an early and easily manageable stage and may well contribute to the management strategy of MTC.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
8/9. Cancer as a marker of genetic medical disease: an unusual case of medullary carcinoma of the kidney.Medullary carcinoma is a recently recognized tumor of the kidney with distinctive microscopic features; the most notable are diffuse and glandular growth patterns, inflammatory infiltrates, and rhabdoid/plasmacytoid cells. It is a clinically aggressive tumor that occurs in relatively young patients. Moreover, this tumor shows a peculiar clinical association: it occurs in patients with sickle cell hemoglobinopathy. The case presented is that of a 37-year-old black woman with a history of bronchial asthma who died suddenly. autopsy showed a 4-cm renal mass with extension to the inferior vena cava and metastases to the liver. Histologic evaluation showed the characteristic findings of medullary carcinoma of the kidney. This diagnosis prompted the investigation and subsequent detection of sickle cell trait in the deceased, alerting the family to the genetic nature of her illness. This case is the first report of this entity since the original described series of patients and shows the unique nature of this cancer as a marker of a genetic medical disease.- - - - - - - - - - ranking = 2keywords = nature (Clic here for more details about this article) |
9/9. Renal medullary carcinoma: report of a case with positive urinary cytology.Renal medullary carcinoma is an aggressive neoplasm of the renal pelvis arising in patients with a history of sickle-cell trait. The authors report a case of renal medullary carcinoma with positive urinary cytology. Due to the location of the tumor in the renal pelvis and the loosely cohesive nature of poorly differentiated neoplasms, the presence of renal medullary carcinoma in a urinary cytology specimen is not surprising. The cytologic characteristics as well as the ultrastructural features are described.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |