780
CORRESPONDENCE AND CORRECTIONS
The immunohistologic results of our case satisfy the criteria for both ES and PNETs of bone. It has been well established that PNET express antigens commonly associated with neuroectodermal phenotypes (NK cell markers and NSE).2"5 However, the case reported by Parham and colleagues was GFAP positive and the tumor cells of our case were GFAP negative. We agree with Parham and colleagues that round cell tumors of the bone encompass a range of more- or less-differentiated tumors. The case reported here shares features with both Parham's case
(clinical and histologic data) and ES or PNET (immunohistologic data). We cannot tell, as yet, whether this case represents a distinct entity or a single phenotype variant. The presence of a specific chromosomal translocation (t), t(ll;22)(q24;q 12), and the expression of the MIC2 gene, in ES and PNET of bone argue in favor of a common neuroectodermal origin." The rapid local lymph node metastasis that occurred in these cases (Parham's and our own) correlates well with the high proliferative rate indicated by mitotic counts and Ki-67 positivity.8 Lymph node metastases usually are not encountered in ES, so we cannot assign a prognostic value to such a local extension. However, the survival rates of patients with metastatic ES at the time of diagnosis remains far below the average commonly accepted rates.9 M. PEUCHMAUR, M.D. P. TOUZET, M.D. N. BROUSSE, M.D.
Service d'Anatomie Pathologique Service d'Orthopedie Infantile Hopital Necker-Enfants Malades Paris, France REFERENCES 1. Parham DM, Thompson E, Fletcher B, Meyer WH. Metastatic small cell tumor
of bone with "true" rosettes and glial fibrillary acidic protein positivity. Am J Clin Pathol 1991;95:166-171. 2. Cavazanna AO, Miser JS, Jefferson J, Triche TJ: Experimental evidence for a neural origin of Ewing's sarcoma of bone. Am J Pathol 1987;127:507-518. 3. Pinto A, Grant LH, Hayes FA, Schell ML, Parham DM: Immunohistochemical expression of neuron-specific enolase and Leu-7 in Ewing's sarcoma of bone. Cancer 1989;64:1266-1273. 4. Ushigome S, Shimoda T, Takaki K, et al: Immunohistochemical and ultrastructural studies of the histogenesis of Ewing's sarcoma and putatively related tumors. Cancer 1989;64:52-62. 5. Lizard-Nacol S, Lizard G, Justrabo E, TurcCarel C: Immunologic characterization of Ewing's sarcoma using mesenchymal and neural markers. Am J Pathol 1989;135:847-855. 6. Turc-Carel C, Aurias A, Mugneret F, et al: Chromosomes in Ewing's sarcoma. I. An avaluation of 85 cases of remarkable consistency of t( 11 ;22Xq24; q 12). Cancer Genet Cytogenet 1988;32:229-238. 7. Ambros IM, Ambros PF, Strehl S, et al: MIC2 is a specific marker for Ewing's sarcoma and peripheral primitive neuroectodermal tumors. Cancer 1991;67: 1886-1893. 8. Ueda T, Aozasa K, Tsujimoto M, et al: Prognosis significance of Ki-67 reactivity in soft tissue sarcomas. Cancer 1989;63: 1607-1611. 9. Crist WM, Kun LE: Common solid tumor of childhood. N Engl J Med 1991; 324: 461-471.
Multilocular Cystic Renal Cell Carcinoma To the Editor:—The lesions reported by Dr. T. Murad and associates1 seem to be examples of Perlmann's tumor 23 ; whether they should be classified as renal cell carcinomas is a moot point. We have experience with two such cases with at least a 5-year follow-up and, in neither instance, was there evidence of aggressive behavior. Until such time as these lesions are
more fully categorized, it might be advisable to classify them under this eponym or call them benign adenomatous multicystic kidney tumors. PAUL K. O'BRIEN, M.B., F.R.C.P. (C). NILAM CLERK, M.B.,F.R.C.P. (C).
Department of Pathology The Etobicoke General Hospital Rexdale, Ontario, Canada
REFERENCES 1. Murad T, Komaiko W, Oyasu R, Bauer K. Multilocular cystic renal cell carcinoma. Am J Clin Pathol 1991;95:633-637. 2. Perlmann S. Uber einen Fall von Lymphangioma cysticum der Niere. Virchows Arch f path Anat 1928;268:524-535. 3. Robinson GL. Perlmann's tumour of the kidney. Br J Surg 1957;44:620-623.
The Author's Reply The cases reported by Perlmann and Robinson share certain microscopic features with our cases of multilocular cystic renal cell carcinoma, such as finding clear cells with small round hyperchromatic nuclei in the wall of these tumors. An im-
portant question is centered around the argument as to how cystic lesions should be classified when clear cells (which would unquestionably be classified as carcinoma cells when found in a solid renal mass) are the principle cells. Because there are
AJ.C.P. • December 1991
no cytologic or immunohistochemical markers to distinguish these two types of cells, it is best to classify multilocular renal mass with clear cells as a carcinoma. The same rationale applies to the debate about the renal adenoma-adenocarcinoma issue.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
labeling for desmin or GFAP (Fig. 1Q. Many tumor cell nuclei were strongly positive for Ki-67. Thus, the clinical and histologic features of our patient are similar to those reported by Parham and colleagues. Our patient was black and had a local lymph node metastasis, both features unusual for ES. No other primary tumor was found. There were abundant rosettes with structures, including a central lumen surrounded by cylindrical cells with basal nuclei associated with the undifferentiated tumor cells. As indicated by Parham and colleagues, this feature has not previously been reported in bone tumors. Whereas the tumor cells of ES are usually PAS positive, the tumor cells of our case were PAS negative.
CORRESPONDENCE AND CORRECTIONS
The immunohistologic results of our case satisfy the criteria for both ES and PNETs of bone. It has been well established that PNET express antigens commonly associated with neuroectodermal phenotypes (NK cell markers and NSE).2"5 However, the case reported by Parham and colleagues was GFAP positive and the tumor cells of our case were GFAP negative. We agree with Parham and colleagues that round cell tumors of the bone encompass a range of more- or less-differentiated tumors. The case reported here shares features with both Parham's case
(clinical and histologic data) and ES or PNET (immunohistologic data). We cannot tell, as yet, whether this case represents a distinct entity or a single phenotype variant. The presence of a specific chromosomal translocation (t), t(ll;22)(q24;q 12), and the expression of the MIC2 gene, in ES and PNET of bone argue in favor of a common neuroectodermal origin." The rapid local lymph node metastasis that occurred in these cases (Parham's and our own) correlates well with the high proliferative rate indicated by mitotic counts and Ki-67 positivity.8 Lymph node metastases usually are not encountered in ES, so we cannot assign a prognostic value to such a local extension. However, the survival rates of patients with metastatic ES at the time of diagnosis remains far below the average commonly accepted rates.9 M. PEUCHMAUR, M.D. P. TOUZET, M.D. N. BROUSSE, M.D.
Service d'Anatomie Pathologique Service d'Orthopedie Infantile Hopital Necker-Enfants Malades Paris, France REFERENCES 1. Parham DM, Thompson E, Fletcher B, Meyer WH. Metastatic small cell tumor
of bone with "true" rosettes and glial fibrillary acidic protein positivity. Am J Clin Pathol 1991;95:166-171. 2. Cavazanna AO, Miser JS, Jefferson J, Triche TJ: Experimental evidence for a neural origin of Ewing's sarcoma of bone. Am J Pathol 1987;127:507-518. 3. Pinto A, Grant LH, Hayes FA, Schell ML, Parham DM: Immunohistochemical expression of neuron-specific enolase and Leu-7 in Ewing's sarcoma of bone. Cancer 1989;64:1266-1273. 4. Ushigome S, Shimoda T, Takaki K, et al: Immunohistochemical and ultrastructural studies of the histogenesis of Ewing's sarcoma and putatively related tumors. Cancer 1989;64:52-62. 5. Lizard-Nacol S, Lizard G, Justrabo E, TurcCarel C: Immunologic characterization of Ewing's sarcoma using mesenchymal and neural markers. Am J Pathol 1989;135:847-855. 6. Turc-Carel C, Aurias A, Mugneret F, et al: Chromosomes in Ewing's sarcoma. I. An avaluation of 85 cases of remarkable consistency of t( 11 ;22Xq24; q 12). Cancer Genet Cytogenet 1988;32:229-238. 7. Ambros IM, Ambros PF, Strehl S, et al: MIC2 is a specific marker for Ewing's sarcoma and peripheral primitive neuroectodermal tumors. Cancer 1991;67: 1886-1893. 8. Ueda T, Aozasa K, Tsujimoto M, et al: Prognosis significance of Ki-67 reactivity in soft tissue sarcomas. Cancer 1989;63: 1607-1611. 9. Crist WM, Kun LE: Common solid tumor of childhood. N Engl J Med 1991; 324: 461-471.
Multilocular Cystic Renal Cell Carcinoma To the Editor:—The lesions reported by Dr. T. Murad and associates1 seem to be examples of Perlmann's tumor 23 ; whether they should be classified as renal cell carcinomas is a moot point. We have experience with two such cases with at least a 5-year follow-up and, in neither instance, was there evidence of aggressive behavior. Until such time as these lesions are
more fully categorized, it might be advisable to classify them under this eponym or call them benign adenomatous multicystic kidney tumors. PAUL K. O'BRIEN, M.B., F.R.C.P. (C). NILAM CLERK, M.B.,F.R.C.P. (C).
Department of Pathology The Etobicoke General Hospital Rexdale, Ontario, Canada
REFERENCES 1. Murad T, Komaiko W, Oyasu R, Bauer K. Multilocular cystic renal cell carcinoma. Am J Clin Pathol 1991;95:633-637. 2. Perlmann S. Uber einen Fall von Lymphangioma cysticum der Niere. Virchows Arch f path Anat 1928;268:524-535. 3. Robinson GL. Perlmann's tumour of the kidney. Br J Surg 1957;44:620-623.
The Author's Reply The cases reported by Perlmann and Robinson share certain microscopic features with our cases of multilocular cystic renal cell carcinoma, such as finding clear cells with small round hyperchromatic nuclei in the wall of these tumors. An im-
portant question is centered around the argument as to how cystic lesions should be classified when clear cells (which would unquestionably be classified as carcinoma cells when found in a solid renal mass) are the principle cells. Because there are
AJ.C.P. • December 1991
no cytologic or immunohistochemical markers to distinguish these two types of cells, it is best to classify multilocular renal mass with clear cells as a carcinoma. The same rationale applies to the debate about the renal adenoma-adenocarcinoma issue.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
labeling for desmin or GFAP (Fig. 1Q. Many tumor cell nuclei were strongly positive for Ki-67. Thus, the clinical and histologic features of our patient are similar to those reported by Parham and colleagues. Our patient was black and had a local lymph node metastasis, both features unusual for ES. No other primary tumor was found. There were abundant rosettes with structures, including a central lumen surrounded by cylindrical cells with basal nuclei associated with the undifferentiated tumor cells. As indicated by Parham and colleagues, this feature has not previously been reported in bone tumors. Whereas the tumor cells of ES are usually PAS positive, the tumor cells of our case were PAS negative.
