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Mucin-Producing Poorly Differentiated Adenocarcinoma of the Thyroid
Path. Res. Pract. 189,608-612 (1993)
Mucin-Producing Poorly Differentiated Adenocarcinoma of the Thyroid A Case Report y. Mizukami1, H. Nakajima2 . Y. Annen 2 , T. Michigishi 3 ,
A. Nonomura 1 and S. Nakamura4
1Pathology Section, 3Nuclear Medicine, 41nternal Medicine, Kanazawa University Hospital, Kanazawa and 2Tonami Citizen Hospital, Tonami, Japan
SUMMARY A rare case of mucin-producing poorly differentiated adenocarcinoma of the thyroid is reported in a 58-year-old man. Light microscopically, the tumor composed of columnar cells, cuboidal cells and spindle cells and these tumor cells showed a various growth pattern; glandular growth with columnar cells, microfollicular growth with cuboidal cells and solid growth with spindle cells. Mucin histochemistry showed scattered foci of mucin production. Immunohistochemistry showed a focal positive staining for thyroglobulin and carcinoembryonic antigen, but a negative staining for calcitonin throughout the tumor. The patient had cervical and axillar lymph node recurrences after the radical operation. The histologic finding of this tumor is peculiar; we report this case briefly.
Introduction Primary mucin-producing tumor of the thyroid gland is extremely rare. Only a few cases of mucin-producing adenocarcinoma of the thyroid including our previously reported cases have been reported 2-4, 7, 9-11. Recently, we encountered a thyroid neoplasm associated with mucin production that had a feature of poorly differentiated adenocarcinoma. This is a case report. Case Report A 57-year-old man was admitted to Tonami Citizen Hospital (Tonami) because of a goiter. He had a goiter for more than 2 years and it began to increase in size over the preceding 6 months. Physical examination disclosed a visible and firm mass, 6 cm in diameter, in the right neck. Multiple lymph nodes were palpable on the right neck and chest roentgenogram was normal. Ultrasound examination disclosed a solid tumor in the right thyroid lobe. 0344-0338/93/0189-0608$3.50/0
Thyroid function tests were within normal ranges; the serum thyroxine was 8.4 !!g/dl (normal range; 4.6-11.0 !!g/dl) and the serum triiodothyronine was 113 ng/dl (95-200 ng/dl). The thyrotropin (TSH) was 1.3 !-lU/m!' The level of CA 19-9 was 36.6 Ulml (less than 37 U/ml) . Total thyroidectomy with right radical neck dissection was performed. The tumor mass was found in the right lobe of the thyroid. The capsule of the right lobe was attached to the adjacent muscle tissues and trachea. After the pathologic examination, a search of the head and neck, lung and gastrointestinal tract for an occult primary cancer failed to reveal any evidence of tumor. In the resected thyroid gland, much of the right lobe was replaced by the tumor mass, measuring 4 X 3 X 3 cm in size. The cut surface of the tumor was grayish-white and in the center of the tumor, a small fibrotic area was observed (Fig. 1). Most of the resected right cervical lymph nodes were enlarged, up to 3 cm in diameter, and were replaced by the tumor. One month after initial operation, the patient had a left cervical node recurrence and the left radical neck dissection combined with 1-131 (120 mCi) © 1993 by Gustav Fischer Verlag, Stuttgart
Mucin-producing Carcinoma of Thyroid . 609
I' , "I' , 'I I " "11" 1 111 I , I " " I " " I " I 'I' , " I' , ,'I' " , I' " Fig. 1. Surgically resected specimen. Cut-surface reveals replacement of the right lobe of the thyroid by tumor tissue.
therapy was performed. Six months after the initial recurrence, the patient had a left axillar lymph node recurrence and the axillar nodes were dissected. Thereafter, the patient has been well with no further recurrences for 10 months. Pathologic Findings An ill-circumscribed tumor measuring 4 x 3 x 3 cm in size was present in the right lobe of the thyroid gland. The
Fig. 2. Low-power view shows the nest of poorly differentiated adenocarcinoma. Various growth pattern from glandular to solid is observed (HE, x 40).
tumor was unencapsulated and infiltrated focally into the perithyroidal soft tissues. Microscopically, the tumor revealed a varied histologic pattern; glandular growth pattern showing some stratification with columnar cells, microfollicular growth with cuboidal cells and solid growth with spindle cells (Fig. 2). No well-developed papillae and psammoma bodies were observed. In the glandular and micro follicular growth areas, colloid material was observed within the lumen (Fig. 3). The columnar and cuboidal cells had vesicular nuclei showing a somewhat ground-glass appearance. There were two or three mitotic figures per 10 high-power fields. In some foci within the glandular growth area, the tumor cells showed a tall columnar shape with basally oriented nuclei, similar to those seen in colon carcinoma (Fig. 4). In the solid growth area, the spindle-shaped tumor cells were arranged showing a sheet-like pattern, but no evidence of intercellular bridges or individual cell keratinization suggesting a squamous metaplasia was observed (Fig. 5). Any evidence suggesting a transformation to anaplastic carcinoma, such as marked nuclear pleomorphism, numerous mitotic figures or giant cell formation, was not found. The tumor was infiltrated beyond the thyroid capsule and invaded into the adjacent soft tissues. The tumor metastases to the cervical lymph nodes showed a similar histologic feature to the primary with a small increase of the solid growth area. Mucin Histochemistry
The following mucin stammgs were used: periodic acid-Schiff reaction (PAS), high iron diamine (HID), colloid iron, alcian blue at pH 2.5 and pH 1.0 and
610 . Y. Mizukami et al.
3
4
7 Fig. 3. In the glandular growth area, columnar-shaped tumor cells are arranged showing some stratification. Colloid material is observed within the lumen (HE, X 200). - Fig. 4. In some foci of the glandular growth area, tumor cells show a high columnar shape with basally oriented nuclei, similar to those seen in colon carcinoma (HE, x 200). - Fig. 5. In the solid growth area, spindle-shaped tumor cells show a sheet-like arrangement (HE, X 100). - Fig. 6. Mucin staining of the tumor. Focally positive staining is observed. HID, X 400 (a) and alcian blue pH 2.5 , X 200 (b). - Fig. 7. Immunohistochemical staining of the tumor. Positive staining for TG is observed not only in the glandular growth area (a), but also in the solid growth area (b). CEA is also detectable using polyclonal antibody (c). (ABC method with hematoxylin counterstain, X 200).
Mucin-producing Carcinoma of Thyroid · 611
mucicarmine. In the scattered foci within the glandular growth area, the tumor cells and the luminal colloid-like material showed a positive result with these mucin stainings (Figs. 6a and 6b). The mucicarmine staining showed a less intense reaction among these mucin stainings. Immunohistochemistry Immunohistochemistry was performed using avidinbiotin-peroxidase complex (ABC) method. The following antibodies were used: thyroglobulin (TG), calcitonin (CT), carcinoembryonic antigen (CEA) (polyclonal and monoclonal), vim entin, keratin, epithelial membrane antigen (EMA) (all purchased from Dakopatts, Glostrup, Denmark). Positive staining for TG was observed focally in the tumor cells and the luminal colloid material in the glandular and microfollicular growth area. A few spindleshaped tumor cells in the solid growth area also showed a positive staining for TG (Figs. 7a and 7b). Calcitonin was negative throughout the tumor. Staining for CEA (using the polyclonal, not absorbed antibody) showed a focal positive reaction in the tumor, but the staining for CEA (using the monoclonal antibody) was entirely negative (Fig. 7 c). Keratin was positive predominantly in the solid growth area, but EMA positivity was more predominant in the glandular growth area. Vim en tin was positive both in the solid and the glandular growth area. Electron Microscopy Fragments of the tumor were sliced into 1 mm 3 blocks, fixed in 2.5% glutaraldehyde and 2% osmium tetroxide,
Fig. 8. Electron microscopic photograph of the mucin-secreting tumor cells. The cytoplasm contains many mucin granules (arrows) (x 3600).
dehydrated in graded ethanols and embedded in Epon 812. Thin sections were stained with uranyl-acetate and lead citrate. Mucin-producing tumor cells were arranged showing a glandular structure. These tumor cells possessed many mucin-containing granules in their cytoplasm (Fig. 8). Membrane-bound, electron-dense granules (secretory granules) were not observed in any tumor cells.
Discussion Primary mucin-producing adenocarcinoma of the thyroid is rare and several cases of this type of thyroid tumor have been reported; mucinous carcinoma 2,3, mucoepidermoid carcinoma4 , 7,9,11, and mucin-producing adenosquamous carcinoma 10. The histogenesis of these mucinproducing tumors of the thyroid has been questionable. Some authors 3,11 believe that they arise from embryonic remnants of salivary gland or thyroglossal duct within the thyroid gland, others5, 7 consider them to originate from solid cell nests and still others lO consider these unusual lesions to originate from metaplasia of thyroid follicular cells. In the present case, the tumor showed a various histologic growth pattern. Mucin-secreting and thyroglobulin-secreting tumor cells were intermingled in this tumor and this finding suggested that the mucin secretion in this tumor might be derived from a metaplasia of the thyroid follicular cell to the mucin-producing cell in the course of less differentiation of the papillary thyroid carcinoma. We previously reported a unique case of mucin-producing adenosquamous carcinoma of the thyroid 10, in which the follicular carcinoma cells showed a metaplasia to both the squamous cell and the mucin-producing cell. Chan et al. l reported that metastatic carcinoma cells from papillary thyroid carcinoma frequently show mucin production . This evidence supports the idea that the mucin production in the current case might be derived from a metaplasia of the carcinoma cell of follicular cell origin to the mucinproducing cell. In the present case, CEA was also expressed in some foci of the carcinoma. The differentiated (papillary and follicular) thyroid carcinomas usually do not produce CEA. However, sporadic cases of Hurthle cell tumor or anaplastic carcinoma have been shown to produce CEA6,8, 13. Schroder et al. 12 showed that CEA detectable using a monoclonal antibody was present only in C-cell tumors of the thyroid. The current tumor showed a negative staining when the monoclonal antibody for CEA was used. This negative finding for CEA (using the monoclonal antibody) and the negative result for calcitonin indicated that the current tumor does not contain a component of medullary carcinoma. We consider that CEA expression detectable using the polyclonal antibody might be associated with the poorer differentiation of the tumor of follicular cell origin. The biological behavior and the clinical prognosis of the present case might not be so good, because this tumor was in an advanced stage and the patient has had an early relapse twice. A careful and long-term follow-up is needed to cure the patient from this rare thyroid tumor.
612 . Y. Mizukami et al. / K. O. Franssila
Acknowledgements The authors thank Mrs Sanae Itoh for the preparation of the manuscript and Miss Mika Tokunou for technical assistance.
References 1 Chan JKC, Tse CCH (1988) Mucin production in metastatic papillary carcinoma of the thyroid. Hum Pathol19: 195-220 2 Deligdisch L, Subhani Z, Gordon RE (1980) Primary mucinous carcinoma of thyroid. Report of a case and ultrastructural study. Cancer 45: 2564-2567 3 Diaz-Perez R, Quiroz H, Nishiyama RE (1976) Primary mucinous adenocarcinoma of the thyroid gland. Cancer 38: 1323-1325 4 Franssila KO, Harach HR (1984) Mucoepidermoid carcinoma of the thyroid. Histopathology 8: 847-860 5 Harach HR (1985) A study on the relationship between solid cell nests and mucoepidermoid carcinoma of the thyroid. Histopathology 9: 195-207
6 Johnson TL, Lloyd RV, Burney RE, Thompson NW (1987) Hurthle cell thyroid tumors. An immunohistochemical study. Cancer 59: 107-112 7 Kato R, Sugai T, Ono S, et al. (1990) Mucoepidermoid carcinoma of the thyroid gland. Cancer 65: 2020-2027 8 LiVolsi VA, Brooks RV, Arendash-Durand B (1987) Anaplastic thyroid tumors: Immunohistology. Am J Clin Pathol 87: 434-442 9 Mizukami Y, Matsubara F, Hashimoto T, et al. (1984) Primary mucoepidermoid carcinoma in the thyroid gland. A case report including an ultrastructural and biochemical study. Cancer 53: 1741-1745 10 Mizukami Y, Matsubara F, Hashimoto T, et al. (1987) Primary mucin-producing adenosquamous carcinoma of the thyroid gland. Acta Pathol Jpn 37: 1157-1164 11 Rhatigan RM, Roque JL, Bucher RL (1977) Mucoepidermoid carcinoma of the thyroid gland. Cancer 39: 210-214 12 Schroder S, Kloppel G (1987) Carcinoembryonic antigen and nonspecific cross reacting antigen in thyroid cancer. Am J Surg Pathol 11: 100-108 13 Swamy Venkatesh YS, Ordonez NG, Schultz PN, et al. (1990) Anaplastic carcinoma of the thyroid. A clinicopathological study of 121 cases. Cancer 66: 321-330
Received April 1, 1992 . Accepted October 30, 1992
Key words: Thyroid - Mucin-production - Poorly differentiated adenocarcinoma Yuji Mizukami, M.D., Pathology Section, Kanazawa University Hospital, 13-1, Takara-machi, Kanazawa, 920, Japan
Critical Commentary to "Mucin-Producing Poorly Differentiated Adenocarcinoma of the Thyroid"
K. O. Franssila Helsinki, Finland The authors describe an unusual thyroid carcinoma composed of glandular structures and spindle cells. The tumour contained focal areas of mucin production, and immunohistochemically the tumour was focally thyroglobulin positive. Mucin production has been reported to occur in medullary thyroid carcinomaS, in some microfollicular (signet ring) thyroid adenomas 2 and in the following rare thyroid tumours: mucoepidermoid carcinoma4, so-called mucinproducing adenosquamous carcinoma, and mucinous carcinoma of the thyroid!. In mucinous carcinoma the majority of tumour cells have been reported to produce mucin 1 but in the other thyroid carcinomas mentioned above only focal mucin production has been detected. It has been suggested that in some of the reported mucin
positive thyroid fumours the positive mucin stain may be a result of staining of carbohydrate components in the breakdown products of thyroglobulin and colloid3 • The tumour described by Mizukami et a1. had focal mucin production and focal thyroglobulin positivity in common with mucoepidermoid carcinoma of the thyroid4 . Moreover, the nuclear type and architectural pattern as well as mucin staining patterns including hyaline bodies surrounded by mucin (Fig. 6b) had some resemblance to this tumour. The present tumour, however, had spindle cell proliferation and scant stroma that are not typical of mucoepidermoid carcinoma of the thyroid. Apparently the tumour does not completely fit to any of the previously described types of thyroid tumour. It can, however, be accepted to be of thyroid origin as thyroglobulin positivity
Mucin-Producing Poorly Differentiated Adenocarcinoma of the Thyroid A Case Report y. Mizukami1, H. Nakajima2 . Y. Annen 2 , T. Michigishi 3 ,
A. Nonomura 1 and S. Nakamura4
1Pathology Section, 3Nuclear Medicine, 41nternal Medicine, Kanazawa University Hospital, Kanazawa and 2Tonami Citizen Hospital, Tonami, Japan
SUMMARY A rare case of mucin-producing poorly differentiated adenocarcinoma of the thyroid is reported in a 58-year-old man. Light microscopically, the tumor composed of columnar cells, cuboidal cells and spindle cells and these tumor cells showed a various growth pattern; glandular growth with columnar cells, microfollicular growth with cuboidal cells and solid growth with spindle cells. Mucin histochemistry showed scattered foci of mucin production. Immunohistochemistry showed a focal positive staining for thyroglobulin and carcinoembryonic antigen, but a negative staining for calcitonin throughout the tumor. The patient had cervical and axillar lymph node recurrences after the radical operation. The histologic finding of this tumor is peculiar; we report this case briefly.
Introduction Primary mucin-producing tumor of the thyroid gland is extremely rare. Only a few cases of mucin-producing adenocarcinoma of the thyroid including our previously reported cases have been reported 2-4, 7, 9-11. Recently, we encountered a thyroid neoplasm associated with mucin production that had a feature of poorly differentiated adenocarcinoma. This is a case report. Case Report A 57-year-old man was admitted to Tonami Citizen Hospital (Tonami) because of a goiter. He had a goiter for more than 2 years and it began to increase in size over the preceding 6 months. Physical examination disclosed a visible and firm mass, 6 cm in diameter, in the right neck. Multiple lymph nodes were palpable on the right neck and chest roentgenogram was normal. Ultrasound examination disclosed a solid tumor in the right thyroid lobe. 0344-0338/93/0189-0608$3.50/0
Thyroid function tests were within normal ranges; the serum thyroxine was 8.4 !!g/dl (normal range; 4.6-11.0 !!g/dl) and the serum triiodothyronine was 113 ng/dl (95-200 ng/dl). The thyrotropin (TSH) was 1.3 !-lU/m!' The level of CA 19-9 was 36.6 Ulml (less than 37 U/ml) . Total thyroidectomy with right radical neck dissection was performed. The tumor mass was found in the right lobe of the thyroid. The capsule of the right lobe was attached to the adjacent muscle tissues and trachea. After the pathologic examination, a search of the head and neck, lung and gastrointestinal tract for an occult primary cancer failed to reveal any evidence of tumor. In the resected thyroid gland, much of the right lobe was replaced by the tumor mass, measuring 4 X 3 X 3 cm in size. The cut surface of the tumor was grayish-white and in the center of the tumor, a small fibrotic area was observed (Fig. 1). Most of the resected right cervical lymph nodes were enlarged, up to 3 cm in diameter, and were replaced by the tumor. One month after initial operation, the patient had a left cervical node recurrence and the left radical neck dissection combined with 1-131 (120 mCi) © 1993 by Gustav Fischer Verlag, Stuttgart
Mucin-producing Carcinoma of Thyroid . 609
I' , "I' , 'I I " "11" 1 111 I , I " " I " " I " I 'I' , " I' , ,'I' " , I' " Fig. 1. Surgically resected specimen. Cut-surface reveals replacement of the right lobe of the thyroid by tumor tissue.
therapy was performed. Six months after the initial recurrence, the patient had a left axillar lymph node recurrence and the axillar nodes were dissected. Thereafter, the patient has been well with no further recurrences for 10 months. Pathologic Findings An ill-circumscribed tumor measuring 4 x 3 x 3 cm in size was present in the right lobe of the thyroid gland. The
Fig. 2. Low-power view shows the nest of poorly differentiated adenocarcinoma. Various growth pattern from glandular to solid is observed (HE, x 40).
tumor was unencapsulated and infiltrated focally into the perithyroidal soft tissues. Microscopically, the tumor revealed a varied histologic pattern; glandular growth pattern showing some stratification with columnar cells, microfollicular growth with cuboidal cells and solid growth with spindle cells (Fig. 2). No well-developed papillae and psammoma bodies were observed. In the glandular and micro follicular growth areas, colloid material was observed within the lumen (Fig. 3). The columnar and cuboidal cells had vesicular nuclei showing a somewhat ground-glass appearance. There were two or three mitotic figures per 10 high-power fields. In some foci within the glandular growth area, the tumor cells showed a tall columnar shape with basally oriented nuclei, similar to those seen in colon carcinoma (Fig. 4). In the solid growth area, the spindle-shaped tumor cells were arranged showing a sheet-like pattern, but no evidence of intercellular bridges or individual cell keratinization suggesting a squamous metaplasia was observed (Fig. 5). Any evidence suggesting a transformation to anaplastic carcinoma, such as marked nuclear pleomorphism, numerous mitotic figures or giant cell formation, was not found. The tumor was infiltrated beyond the thyroid capsule and invaded into the adjacent soft tissues. The tumor metastases to the cervical lymph nodes showed a similar histologic feature to the primary with a small increase of the solid growth area. Mucin Histochemistry
The following mucin stammgs were used: periodic acid-Schiff reaction (PAS), high iron diamine (HID), colloid iron, alcian blue at pH 2.5 and pH 1.0 and
610 . Y. Mizukami et al.
3
4
7 Fig. 3. In the glandular growth area, columnar-shaped tumor cells are arranged showing some stratification. Colloid material is observed within the lumen (HE, X 200). - Fig. 4. In some foci of the glandular growth area, tumor cells show a high columnar shape with basally oriented nuclei, similar to those seen in colon carcinoma (HE, x 200). - Fig. 5. In the solid growth area, spindle-shaped tumor cells show a sheet-like arrangement (HE, X 100). - Fig. 6. Mucin staining of the tumor. Focally positive staining is observed. HID, X 400 (a) and alcian blue pH 2.5 , X 200 (b). - Fig. 7. Immunohistochemical staining of the tumor. Positive staining for TG is observed not only in the glandular growth area (a), but also in the solid growth area (b). CEA is also detectable using polyclonal antibody (c). (ABC method with hematoxylin counterstain, X 200).
Mucin-producing Carcinoma of Thyroid · 611
mucicarmine. In the scattered foci within the glandular growth area, the tumor cells and the luminal colloid-like material showed a positive result with these mucin stainings (Figs. 6a and 6b). The mucicarmine staining showed a less intense reaction among these mucin stainings. Immunohistochemistry Immunohistochemistry was performed using avidinbiotin-peroxidase complex (ABC) method. The following antibodies were used: thyroglobulin (TG), calcitonin (CT), carcinoembryonic antigen (CEA) (polyclonal and monoclonal), vim entin, keratin, epithelial membrane antigen (EMA) (all purchased from Dakopatts, Glostrup, Denmark). Positive staining for TG was observed focally in the tumor cells and the luminal colloid material in the glandular and microfollicular growth area. A few spindleshaped tumor cells in the solid growth area also showed a positive staining for TG (Figs. 7a and 7b). Calcitonin was negative throughout the tumor. Staining for CEA (using the polyclonal, not absorbed antibody) showed a focal positive reaction in the tumor, but the staining for CEA (using the monoclonal antibody) was entirely negative (Fig. 7 c). Keratin was positive predominantly in the solid growth area, but EMA positivity was more predominant in the glandular growth area. Vim en tin was positive both in the solid and the glandular growth area. Electron Microscopy Fragments of the tumor were sliced into 1 mm 3 blocks, fixed in 2.5% glutaraldehyde and 2% osmium tetroxide,
Fig. 8. Electron microscopic photograph of the mucin-secreting tumor cells. The cytoplasm contains many mucin granules (arrows) (x 3600).
dehydrated in graded ethanols and embedded in Epon 812. Thin sections were stained with uranyl-acetate and lead citrate. Mucin-producing tumor cells were arranged showing a glandular structure. These tumor cells possessed many mucin-containing granules in their cytoplasm (Fig. 8). Membrane-bound, electron-dense granules (secretory granules) were not observed in any tumor cells.
Discussion Primary mucin-producing adenocarcinoma of the thyroid is rare and several cases of this type of thyroid tumor have been reported; mucinous carcinoma 2,3, mucoepidermoid carcinoma4 , 7,9,11, and mucin-producing adenosquamous carcinoma 10. The histogenesis of these mucinproducing tumors of the thyroid has been questionable. Some authors 3,11 believe that they arise from embryonic remnants of salivary gland or thyroglossal duct within the thyroid gland, others5, 7 consider them to originate from solid cell nests and still others lO consider these unusual lesions to originate from metaplasia of thyroid follicular cells. In the present case, the tumor showed a various histologic growth pattern. Mucin-secreting and thyroglobulin-secreting tumor cells were intermingled in this tumor and this finding suggested that the mucin secretion in this tumor might be derived from a metaplasia of the thyroid follicular cell to the mucin-producing cell in the course of less differentiation of the papillary thyroid carcinoma. We previously reported a unique case of mucin-producing adenosquamous carcinoma of the thyroid 10, in which the follicular carcinoma cells showed a metaplasia to both the squamous cell and the mucin-producing cell. Chan et al. l reported that metastatic carcinoma cells from papillary thyroid carcinoma frequently show mucin production . This evidence supports the idea that the mucin production in the current case might be derived from a metaplasia of the carcinoma cell of follicular cell origin to the mucinproducing cell. In the present case, CEA was also expressed in some foci of the carcinoma. The differentiated (papillary and follicular) thyroid carcinomas usually do not produce CEA. However, sporadic cases of Hurthle cell tumor or anaplastic carcinoma have been shown to produce CEA6,8, 13. Schroder et al. 12 showed that CEA detectable using a monoclonal antibody was present only in C-cell tumors of the thyroid. The current tumor showed a negative staining when the monoclonal antibody for CEA was used. This negative finding for CEA (using the monoclonal antibody) and the negative result for calcitonin indicated that the current tumor does not contain a component of medullary carcinoma. We consider that CEA expression detectable using the polyclonal antibody might be associated with the poorer differentiation of the tumor of follicular cell origin. The biological behavior and the clinical prognosis of the present case might not be so good, because this tumor was in an advanced stage and the patient has had an early relapse twice. A careful and long-term follow-up is needed to cure the patient from this rare thyroid tumor.
612 . Y. Mizukami et al. / K. O. Franssila
Acknowledgements The authors thank Mrs Sanae Itoh for the preparation of the manuscript and Miss Mika Tokunou for technical assistance.
References 1 Chan JKC, Tse CCH (1988) Mucin production in metastatic papillary carcinoma of the thyroid. Hum Pathol19: 195-220 2 Deligdisch L, Subhani Z, Gordon RE (1980) Primary mucinous carcinoma of thyroid. Report of a case and ultrastructural study. Cancer 45: 2564-2567 3 Diaz-Perez R, Quiroz H, Nishiyama RE (1976) Primary mucinous adenocarcinoma of the thyroid gland. Cancer 38: 1323-1325 4 Franssila KO, Harach HR (1984) Mucoepidermoid carcinoma of the thyroid. Histopathology 8: 847-860 5 Harach HR (1985) A study on the relationship between solid cell nests and mucoepidermoid carcinoma of the thyroid. Histopathology 9: 195-207
6 Johnson TL, Lloyd RV, Burney RE, Thompson NW (1987) Hurthle cell thyroid tumors. An immunohistochemical study. Cancer 59: 107-112 7 Kato R, Sugai T, Ono S, et al. (1990) Mucoepidermoid carcinoma of the thyroid gland. Cancer 65: 2020-2027 8 LiVolsi VA, Brooks RV, Arendash-Durand B (1987) Anaplastic thyroid tumors: Immunohistology. Am J Clin Pathol 87: 434-442 9 Mizukami Y, Matsubara F, Hashimoto T, et al. (1984) Primary mucoepidermoid carcinoma in the thyroid gland. A case report including an ultrastructural and biochemical study. Cancer 53: 1741-1745 10 Mizukami Y, Matsubara F, Hashimoto T, et al. (1987) Primary mucin-producing adenosquamous carcinoma of the thyroid gland. Acta Pathol Jpn 37: 1157-1164 11 Rhatigan RM, Roque JL, Bucher RL (1977) Mucoepidermoid carcinoma of the thyroid gland. Cancer 39: 210-214 12 Schroder S, Kloppel G (1987) Carcinoembryonic antigen and nonspecific cross reacting antigen in thyroid cancer. Am J Surg Pathol 11: 100-108 13 Swamy Venkatesh YS, Ordonez NG, Schultz PN, et al. (1990) Anaplastic carcinoma of the thyroid. A clinicopathological study of 121 cases. Cancer 66: 321-330
Received April 1, 1992 . Accepted October 30, 1992
Key words: Thyroid - Mucin-production - Poorly differentiated adenocarcinoma Yuji Mizukami, M.D., Pathology Section, Kanazawa University Hospital, 13-1, Takara-machi, Kanazawa, 920, Japan
Critical Commentary to "Mucin-Producing Poorly Differentiated Adenocarcinoma of the Thyroid"
K. O. Franssila Helsinki, Finland The authors describe an unusual thyroid carcinoma composed of glandular structures and spindle cells. The tumour contained focal areas of mucin production, and immunohistochemically the tumour was focally thyroglobulin positive. Mucin production has been reported to occur in medullary thyroid carcinomaS, in some microfollicular (signet ring) thyroid adenomas 2 and in the following rare thyroid tumours: mucoepidermoid carcinoma4, so-called mucinproducing adenosquamous carcinoma, and mucinous carcinoma of the thyroid!. In mucinous carcinoma the majority of tumour cells have been reported to produce mucin 1 but in the other thyroid carcinomas mentioned above only focal mucin production has been detected. It has been suggested that in some of the reported mucin
positive thyroid fumours the positive mucin stain may be a result of staining of carbohydrate components in the breakdown products of thyroglobulin and colloid3 • The tumour described by Mizukami et a1. had focal mucin production and focal thyroglobulin positivity in common with mucoepidermoid carcinoma of the thyroid4 . Moreover, the nuclear type and architectural pattern as well as mucin staining patterns including hyaline bodies surrounded by mucin (Fig. 6b) had some resemblance to this tumour. The present tumour, however, had spindle cell proliferation and scant stroma that are not typical of mucoepidermoid carcinoma of the thyroid. Apparently the tumour does not completely fit to any of the previously described types of thyroid tumour. It can, however, be accepted to be of thyroid origin as thyroglobulin positivity