Institute of Molecular Pathology and Immunology of the University of Porto,. Portugal. Difficult Cases of Thyroid Pathology. The summer issue of Endocrine ...
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Difficult Cases of Thyroid Pathology
Endocrine Pathology, vol. 13, no. 4, 369–370, Winter 2002 © Copyright 2002 by Humana Press Inc. All rights of any nature whatsoever reserved. 1046–3976/02/13:369–370/ $20.00
The summer issue of Endocrine Pathology included a series of articles summarizing the International Case Conferences held at the Fifth Annual Meeting of the Japan Endocrine Pathology Society [1–5]. The two thyroid tumors reported by Kakudo et al. [2] were selected because they raise very difficult diagnostic problems. I would like to offer several comments on those cases. In case 1 the main issue was to decide whether or not there was enough evidence to make a diagnosis of follicular variant of papillary thyroid carcinoma (FVPTC) [2]. This is the most frequent problem now encountered in thyroid surgical pathology [6,7], and it would have been worthwhile discussing it in greater depth. It would also have been helpful to have a much better documentation of the case at different levels of magnification. With the restricted evidence available, I would favor the possibility of an FVPTC rather than a follicular adenoma, thus joining the two American pathologists who made that diagnosis [2]. However, further histological evidence is unquestionably needed. As Kakudo et al. [2] rightfully stress, it would be good to have additional immunohistochemical and/or molecular genetic evidence; besides ret/PTC, HBME-1, and galectin-1 [2], I would suggest searching for the presence of cytokeratin 19 and sialyl-Lewis x [8,9]. Case 2 is also very interesting and difficult. As in case 1, better documentation of the lesion, especially at lower magnification, with a more precise macroscopic description of the lesion, would probably
have helped both in establishing the diagnosis and in enabling the reader to join the diagnostic game. The lesion does not look like a poorly differentiated/undifferentiated carcinoma, or an adenoma, since it is described as “a circumscribed, very focally encapsulated lesion.” The age of the patient, 12 yr, is also an important diagnostic consideration. Mainly in consultancy cases we have seen foci of extremely pleomorphic and bizarre giant cells, with low mitotic indices and no foci of necrosis, occurring in nodular goiters or adenomas, with or without Hürthle cell features. The patients usually are young females. As far as we know, these lesions have followed a benign course, but our experience is too limited to draw any definitive conclusion on their clinical evolution. As Kakudo et al. [2] stress, analysis of the invasiveness of a follicular lesion is crucial for achieving a diagnosis, and that information in this particular case was missing. All in all, I think it is useful to publish articles on difficult cases. However, both the experts and the readers need to have access to the clinical information, to all the details of the macroscopy of the lesions, and to a thorough sampling of the relevant material in order for the exercise to be scientifically sound. Manuel Sobrinho-Simões, MD, PHD Professor of Pathology, Medical Faculty of the University of Porto Director, IPATIMUP— Institute of Molecular Pathology and Immunology of the University of Porto, Portugal 369
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References 1. Sano T, Kovacs K, Asa SL, Yamada S, Sanno N, Yokoyama S, Takami H. Pituitary adenoma with “Honeycomb Golgi” appearance showing phenotypic change at recurrence from clinically nonfunctioning to typical cushing disease. Endocr Pathol 13:125–130, 2002. 2. Kakudo K, Katoh R, Sakamoto A, Asa S, DeLellis RA, Carney JA, Naganuma H, Kameyama K, Takami H. Thyroid gland: international case conference. Endocr Pathol 13:131–134, 2002. 3. Kameyama K, DeLellis RA, Lloyd RV, Kakudo K, Takami HE. Parathyroid carcinomas: can clinical outcomes for parathyroid carcinomas be determined by histologic evaluation alone? Endocr Pathol 13:135–139, 2002. 4. Sasano H, Suziki T, Irle J, Kawal K, Alba M, McNicol AM, Takami H. Adrenal cortical diseases: international case conference. Endocr Pathol 13:141–148, 2002. 5. Kumaki N, Kajlwara H, Kameyama K, DeLellis RA, Asa SL, Osamura RY, Takami
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H. Prediction of malignant behavior of pheochromocytomas and paragangliomas using immunohistochemical techniques. Endocr Pathol 13:149–156, 2002. Baloch ZW, LiVolsi VA. Follicular-patterned lesions of the thyroid: the bane of the pathologist. Am J Clin Pathol 117:143–150, 2002. Castro P, Fonseca E, Magalhães J, SobrinhoSimões M. Follicular, papillary and “hybrid” carcinomas of the thyroid. Endocr Pathol 13: 313–320, 2002. Fonseca E, Nesland JM, Hoie J, SobrinhoSimões M. Pattern of expression of intermediate cytokeratin filaments in the thyroid gland: an immunohistochemical study of simple and stratified epithelial type cytokeratins. Virchows Archiv 430:239–245, 1997. Alves P, Soares P, Fonseca E, Sobrinho-Simoes M. Papillary thyroid carcinoma overexpresses fully and underglycosylated mucins together with native and sialylated simple mucin antigens and histo-blood group antigens. Endocr Pathol 10:305–313, 1999.
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The Author’s Reply: To the Editor
We thank Professor Sobrinho-Simoes for his comments on our article (K. Kakudo et al. Endocr Pathol 13:131–134, 2002) (1). In connection with our case 1, we certainly agree with him that the diagnosis of the follicular variant of papillary carcinoma may be difficult. As he points out, a number of immunostains, including cytokeratin 19 and sialyl-Lewis, may be helpful in establishing the diagnosis. Dr. Hirokawa with our coauthorship recently published a paper on observer variation of encapsulated follicular lesions of the thyroid gland in Am J Surg Pathol, in which significant observer disagreement is again shown (2). Regarding case 2, his experience with thyroid tumors in young patients having bizarre nuclei is of great interest, particularly in view of the rarity of such lesions. We look forward to seeing his formal report on these lesions.
Kennichi Kakudo, MD Department of Pathology, Wakayama Medical University, Wakayama, Japan J. Aidan Carney, MD Emeritus Member, Department of Laboratory Medicine and Pathology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota, USA
References 1. Kakudo K, Katoh R, Sakamoto A, et al. Thyroid gland: International Case Conference. Endocr Pathol 13: 131–134, 2002. 2. Hirokawa M, Carney JA, Goellner JR, et al. Observer variation of encapsulated follicular lesions of the thyroid gland. Am J Surg Pathol 26:1508–1514, 2002.
Endocrine Pathology, vol. 13, no. 4, 371, Winter 2002 © Copyright 2002 by Humana Press Inc. All rights of any nature whatsoever reserved. 1046–3976/02/13:371/ $20.00
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