Postgraduate Medicine
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
A Conservative Approach to Treatment of Thyroid Cancer George Crile Jr. To cite this article: George Crile Jr. (1975) A Conservative Approach to Treatment of Thyroid Cancer, Postgraduate Medicine, 57:7, 111-115, DOI: 10.1080/00325481.1975.11714078 To link to this article: http://dx.doi.org/10.1080/00325481.1975.11714078
Published online: 07 Jul 2016.
Submit your article to this journal
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Citing articles: 5 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ipgm20 Download by: [Australian Catholic University]
Date: 21 August 2017, At: 14:18
co sder • What treatment would you recommend for a 30-year-old patient with a thyroid nodule that is found on aspiration biopsy to be a papillary carcinoma? • Should the operation be the same if the lesion is a medullary carcinoma? • ln what circumstances would total thyroidectomy be indicated?
GEORGE CRILE, JR., MD
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
Cleveland Clinic, Cleveland
A Conservative Approach to Treatrnent of Thyroid Cancer Much of the controversy about the treatment of thyroid cancer is the result of poor communication between pathologists and surgeons and the lack of a universally accepted system of classification of the disease. Fear of cancer of the thyroid has encouraged the unnecessary surgical removal of many benign nodules of the gland. About one third of ali thyroid nodules are cystic lesions, and the great majority of these cysts-95 %--can be treated by aspiration and, if indicated, by subsequent intralesional injection of an appropriate sclerosing agent. The cytologie examination of specimens removed from solid thyroid nodules by aspiration biopsy has proved to be a very valuable diagnostic procedure. The only neoplasm of the gland which cannat be diagnosed with certainty by cytologie examination is encapsulated angieinvasive carcinoma. However, this lesion often identifies itself because it is extremely cellular and shows sorne malignant activity in the configuration of the nucleus. At present, my colleagues and 1 at the Cleveland Clinic do not operate on patients with thyroiditis, Graves' disease, or clearly benign
Vol. 57 • No. 7 • June 1975 • POSTGRADUATE MEDICINE
adenomas or cysts of the thyroid unless they are big nodular goiters with obstructive symptoms. Malignancy is really the only indication for thyroidectomy, and malignant lesions can be differentiated by cytologie examination of specimens removed by aspiration biopsy. Technique of Aspiration Biopsy
After induction of local anesthesia, an 18gauge needle is inserted into the thyroid nodule. If the lesion is cystic, the fluid is aspirated and submitted to the pathologist for examination. If a solid mass is encountered, aspiration of cellular material is possible by removing the biopsy needle while maintaining strong suction. Immediate aspiration of Zenker's solution or other appropriate fixative into the syringe usually provides enough material for cytologie examination. By centrifuging the solution and preparing a cell black, the pathologist usually can recognize the majority of malignant tumors of the thyroid. Papillary cancers and ali of the more malignant types of thyroid tumors are easily recognized, but it is sometimes difficult to differentiate
111
a cellular adenoma from a well-differentiated encapsulated adenocarcinoma. There is thus a small gray area necessitating the removal of sorne benign adenomas in arder to be able to insure the recognition of carcinoma. A Note on Classification of Thyroid Cancers
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
The entire problem of management of thyroid cancer is related to the histologie characteristics of the lesion. It is unfortunate that
A diagnosis of papillary carcinoma is almost a gross diagnosis, because the lesions are not encapsulated and do not resemble adenomas. The three histologie subgroups of papillary carcinoma behave biologically in the same manner, and ail are equally curable. Papillary neoplasms metastasize primarily to regional lymph nades and infrequently metastasize to lungs or bane. Although the tumors invade blood vessels, there is so much resistance to this type of cancer
Most papillary thyroid carcinomas in children and young adults who have undergone irradiation are endocrine-dependent and will not grow if suppressive doses of desiccated thyroid are given.
thyroid cancers are classified as papillary or follicular or are differentiated by morphologie characteristics alone rather than by biologie behavior. A pathologist who classifies tumors morphologieally may, in making the final diagnosis, fail to discriminate between a well-differentiated nonencapsulated tumor (ie, one that is predominantly follieular with only a few papillary areas) and a weil-differentiated encapsulated follicular carcinoma. Either of these may be designated follicular carcinoma. To be meaningful, a classification must take into account the biologie behavior of a neoplasm as weil as its morphologie characteristies. Papillary Carcinoma
Papillary carcinoma is the most common form of malignant neoplasm of the thyroid, accounting for 60% to 70% of ail thyroid cancers. These tumors, occurring chiefly in young persans from the ages of puberty through 45 years, often develop a few years after radiation therapy for sorne benign condition of the head, neck, or chest. The tumors may be pure papillary, mixed follicular and papillary, or predominantly follicular with only a few papillary elements.
112
that the occurrence of distant metastasis is rare. lt is now weil established that neither total thyroidectomy nor radical neck dissection is often necessary in the treatment of papillary thyroid cancer. Morbidity can be avoided if total thyroidectomy is clone only when there is gross evidence of cancer bilaterally or bilateral involvement of lymph nades. When the disease is unilateral, total lobectomy on the affected side and removal of the isthmus and the major portion of the contralateral lobe, sparing enough of the thyroid capsule to support the parathyroids, are ail that is required. The conventional radical neck dissection is almost never· necessary, and results that are equal from the standpoint of cure can be obtained without sacrifice of the sternocleidomastoid muscle or 11 th nerve. In patients undergoing the modified neck dissection, there is no deformity of the neck. AU patients are given suppressive doses of desiecated thyroid as a prophylactic measure. Lymph nades involved in papillary thyroid cancer are usually those located behind the thyroid gland and extending dawn into the mediastinum. Less often, the lateral nades in the jugular chain are involved. Nodal metastases
POSTGRAOUATE MEDICINE • June 1975 • Vol. 57 • No. 7
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
may encase the recurrent laryngeal nerve but rarely are invasive. Sacrifice of the nerve at operation usually is unnecessary unless the larynx is paralyzed preoperatively. Transthoracic mediastinal dissection seldom is required because nades adhere ta each ether and can be removed through the neck incision. On rare occasions when previous operations on the neck have caused scarring, thoracotomy and open mediastinal dissection are necessary. At the Cleveland Clinic, these measures have been required in only two of about 600 patients undergoing operation for papillary thyroid carcinoma. The snowflake type of pulmonary metastasis which characterizes papillary carcinoma of the thyroid occasionally can be treated successfully with radioactive iodine, but use of this modality in cases of extensive pulmonary metastasis may cause excessive pulmonary fibrosis and death. We prefer ta give these patients suppressive doses of thyroid hormone, because a higher proportion will respond ta this form of therapy than ta radioactive iodine. Pulmonary metastasis can be treated by thyroid suppression alone. When a papillary carcinoma responds ta thyroid suppression, the favorable effect will persist for as long as the treatment is continued. I have never seen a papillary thyroid turner escape from hormonal suppression, as breast or prostatic cancer is known ta do. In a patient who has received radiation therapy, it is possible for a papillary carcinoma ta change into an undifferentiated carcinoma with a hopeless prognosis. The prognosis for survival of young patients with papillary carcinoma of the thyroid is good, their life expectancy following effective treatment being almost normal. A follow-up survey of 231 patients with papillary carcinoma treated at the Cleveland Clinic showed that only 2% of those who were traced for 5 ta 20 years had died of cancer, 1% were living with uncontrollable cancer, and 95% had lived for five years. Metastasis ta regional lymph nades was noted in 65% of the patients in the series, and pulmonary metastasis was demonstrable before operation in 4%. Thirteen percent underwent a
Vol. 57 • No. 7 • June 1975 • POSTGRADUATE MEDICINE
GEORGE CRILE, JR. Dr. Crile is in the department of general surgery, Cleveland Clinic, Cleveland.
secondary operation ta remove a contralateral node outside the field of the primary surgical procedure. A change in the ultimate prognosis related ta the overlooking of the nodal involvement in these cases was indiscernible. The deaths from cancer in the series were unrelated ta local recurrence or inability ta control the disease in the gland but were attributed ta systemic metastasis present at the time of operation or developing afterward. Most of the papillary thyroid carcinomas that occur in children and young adults with a history of radiation therapy are endocrine-dependent and will not grow if suppressive doses of desiccated thyroid are given. It is therefore unnecessary ta perform radical surgery in these young people, because once a remission of papillary carcinoma is established, it tends ta persist indefinitely. The surgeon should remove as much of the cancer as is possible without inflicting severe morbidity, such as tetany or nerve injury. Moreover, in a case with bilateral encasernent of the recurrent laryngeal nerve, a trial of suppressive therapy would be better than sacrifice of the nerve. The prognosis of papillary thyroid cancer is much less favorable in persans more than 50 years of age. The rare tall-cell variant of this neoplasm which occurs in aider persans can have a mortality rate as high as 30%. Angioinvasive Follicular Carcinoma
Encapsulated angioinvasive follicular carcinoma of the thyroid and its more serious vari-
113
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
ant, invasive adenocarcinoma, tend ta invade blood vessels and ta metastasize almost exclusively via the bloodstream, spreading ta the lungs and bane but seldom involving regional lymph nades. Fortunately, sorne of these metastatic lesions concentrate radioactive iodine avidly and can be controlled by administration of this substance after surgical removal of the thyroid lesion. These encapsulated tumors are almost never
Anaplastie carcinoma ofte·n is suspected clinically by its rapid growth, and the diagnosis is confirmed by aspiration biopsy.
multicentric. Grossly they resemble benign cellular adenomas, but microscopically they show invasion of blood vessels. A true benign adenoma is sharply encapsulated and cellular and has no invasive characteristics. An optimal prognosis for a patient with encapsulated follicular carcinoma of the thyroid is provided by complete removal of the affected lobe of the gland. Attempts ta perform total thyroidectomy and node dissection are useless and usually increase morbidity. lt is important, however, ta remove the turner with die capsule intact, preferably by lobectomy, sa turner tissue does not become implanted in the wound. When removal is complete, the prognosis is less favorable for a man than for a woman, especially if he is elderly. The more serious invasive adenocarcinomas tend ta occur in persans more than 50 years of age and carry a poor prognosis. Invasive Follicular Carcinoma
Invasive follicular thyroid carcinoma, a very lethal turner, grows slowly. Our follow-up survey showed that more than half of the patients
114
who died from this form of malignant turner survived for more than five years after operation. Whether or not an encapsulated angieinvasive follicular adenocarcinoma represents an early phase of an invasive follicular adenocarcinoma is difficult ta determine, but 1 doubt that it does. Analyses of cases of these types of follicular carcinoma taking into account the patients' age and sex and the duration of disease suggest that each is a separate entity and does not originate in another type of neoplasm. Although invasive follicular carcinoma grows slowly, and a patient with metastases may live for many years, our experience has shawn it ta be ultimately fatal, death usually being caused by systemic metastasis. Angioinvasion is a prominent histologie feature, and distant metastasis seems ta occur via the bloodstream before the diagnosis is made. Operations in these cases are chiefly palliative. If lymph nades are involved, they should be removed as simply as possible, along with the primary tumor, without adding the morbidity of a radical surgical procedure. Medullary (Solid) Carcinoma
Medullary (solid) thyroid carcinoma is a turner without an identifiable capsule, one that is undifferentiated in structure with individual cells that are regular and not anaplastie. This thyroid neoplasm frequently produces an amylaid stroma which is demonstrable with special stains. The turner is locally invasive and metastasizes bath ta the regionallymph nades and via the bloodstream. Although the majority of patients eventually succumb ta the disease, the lesion does tend ta grow slowly. Many of our patients have lived for five years or more after treatment. Treatment of medullary carcinoma is the same as treatment of papillary carcinoma of the thyroid, ie, nodal dissection and total lobectomy on the affected side, removal of the isthmus, and almost total removal of the lobe on the contralateral side, leaving the posterior capsule ta protect the parathyroids. 1 do not like ta perform total thyroidectomy unless there is bilateral nodal involvement or clinical evidence of bi-
POSTGRADUATE MEDICINE • June 1975 • Vol. 57 • No. 7
lateral involvement of the gland. The incidence of tetany after total thyroidectomy has been rather high at the Cleveland Clinic, but we have now almost eliminated permanent tetany by leaving an intact posterior capsule on the contralateral side. These tumors rarely recur on the contralateral side.
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
Anaplastie Carcinoma
Anaplastie carcinoma of the thyroid is among the most malignant of tumors. The course of the disease from onset to death is usually less than a year and often is as short as four months. The tumor, usually occurring spontaneously in a persan 60 years of age or older, is characterized by local invasion and metastases to regional lymph nodes and to the lungs. Anaplastie carcinoma frequently is suspected clinically by its rapid growth, and the diagnosis confirmed by aspiration biopsy. Most of these lesions are inoperable when diagnosed, and the patients are best treated by aspiration biopsy and irradiation. Tissue damage resulting from surgical procedures causes the tumor to grow and systemic metastases to develop even more rapidly. Tracheostomy performed in the course of a radical operation allows the tumor to fungate into the trachea, with consequent bleeding and obstruction. Al-
though anaplastie carcinoma is not a radiosensitive tumor, irradiation may retard growth of the primary lesion and may be of palliative value until death occurs from systemic metastasis. Summary
Malignant lesions of the thyroid can be differentiated from benign tumors by cytologie examination of specimens removed by aspiration biopsy. To be meaningful, a classification of thyroid cancers must take into account the biologie behavior as well as the morphologie characteristics of the lesions. Papillary c;:ucinomas account for 60% to 70% of all thyroid cancers and metastasize primarily to regional lymph nodes. When the disease is unilateral, the operarive procedure recommended is total lobectomy on the affected side plus removal of the isthmus and a major portion of the contralateral lobe, sparing enough of the thyroid capsule to support the parathyroids. Total thyroidectomy and radical neck dissection are seldom indicated. Address reprint requests to George Crile, Jr., MD, Cleveland Clinic, 2020 E 93rd St, Cleveland, OH 44106. For ReadySource on thyroid management, see page 151. Summary self-test on thyroid management begins on page 144.
uest1on Match each type of thyroid cancer with one or more characteristics. 1. Invasive adenocarcinoma 2. Medullary carcinoma 3. Papillary carcinoma 4. Angioinvasive follicular carcinoma
d
a b, c
e, f
a. Tends to metastasize bath to regional lymph nod es and via the blood b. lnfrequently metastasizes to distant sites c. Nonencapsulated, does not resemble adenoma d. Tends to occur in persans over 50 years of age e. Metastasizes al most solely via bloodstream f. Encapsulated, grossly resembles adenoma
Vol. 57 • No. 7 • June 1975 • POSTGRADUATE MEDICINE
115
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
A Conservative Approach to Treatment of Thyroid Cancer George Crile Jr. To cite this article: George Crile Jr. (1975) A Conservative Approach to Treatment of Thyroid Cancer, Postgraduate Medicine, 57:7, 111-115, DOI: 10.1080/00325481.1975.11714078 To link to this article: http://dx.doi.org/10.1080/00325481.1975.11714078
Published online: 07 Jul 2016.
Submit your article to this journal
View related articles
Citing articles: 5 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ipgm20 Download by: [Australian Catholic University]
Date: 21 August 2017, At: 14:18
co sder • What treatment would you recommend for a 30-year-old patient with a thyroid nodule that is found on aspiration biopsy to be a papillary carcinoma? • Should the operation be the same if the lesion is a medullary carcinoma? • ln what circumstances would total thyroidectomy be indicated?
GEORGE CRILE, JR., MD
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
Cleveland Clinic, Cleveland
A Conservative Approach to Treatrnent of Thyroid Cancer Much of the controversy about the treatment of thyroid cancer is the result of poor communication between pathologists and surgeons and the lack of a universally accepted system of classification of the disease. Fear of cancer of the thyroid has encouraged the unnecessary surgical removal of many benign nodules of the gland. About one third of ali thyroid nodules are cystic lesions, and the great majority of these cysts-95 %--can be treated by aspiration and, if indicated, by subsequent intralesional injection of an appropriate sclerosing agent. The cytologie examination of specimens removed from solid thyroid nodules by aspiration biopsy has proved to be a very valuable diagnostic procedure. The only neoplasm of the gland which cannat be diagnosed with certainty by cytologie examination is encapsulated angieinvasive carcinoma. However, this lesion often identifies itself because it is extremely cellular and shows sorne malignant activity in the configuration of the nucleus. At present, my colleagues and 1 at the Cleveland Clinic do not operate on patients with thyroiditis, Graves' disease, or clearly benign
Vol. 57 • No. 7 • June 1975 • POSTGRADUATE MEDICINE
adenomas or cysts of the thyroid unless they are big nodular goiters with obstructive symptoms. Malignancy is really the only indication for thyroidectomy, and malignant lesions can be differentiated by cytologie examination of specimens removed by aspiration biopsy. Technique of Aspiration Biopsy
After induction of local anesthesia, an 18gauge needle is inserted into the thyroid nodule. If the lesion is cystic, the fluid is aspirated and submitted to the pathologist for examination. If a solid mass is encountered, aspiration of cellular material is possible by removing the biopsy needle while maintaining strong suction. Immediate aspiration of Zenker's solution or other appropriate fixative into the syringe usually provides enough material for cytologie examination. By centrifuging the solution and preparing a cell black, the pathologist usually can recognize the majority of malignant tumors of the thyroid. Papillary cancers and ali of the more malignant types of thyroid tumors are easily recognized, but it is sometimes difficult to differentiate
111
a cellular adenoma from a well-differentiated encapsulated adenocarcinoma. There is thus a small gray area necessitating the removal of sorne benign adenomas in arder to be able to insure the recognition of carcinoma. A Note on Classification of Thyroid Cancers
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
The entire problem of management of thyroid cancer is related to the histologie characteristics of the lesion. It is unfortunate that
A diagnosis of papillary carcinoma is almost a gross diagnosis, because the lesions are not encapsulated and do not resemble adenomas. The three histologie subgroups of papillary carcinoma behave biologically in the same manner, and ail are equally curable. Papillary neoplasms metastasize primarily to regional lymph nades and infrequently metastasize to lungs or bane. Although the tumors invade blood vessels, there is so much resistance to this type of cancer
Most papillary thyroid carcinomas in children and young adults who have undergone irradiation are endocrine-dependent and will not grow if suppressive doses of desiccated thyroid are given.
thyroid cancers are classified as papillary or follicular or are differentiated by morphologie characteristics alone rather than by biologie behavior. A pathologist who classifies tumors morphologieally may, in making the final diagnosis, fail to discriminate between a well-differentiated nonencapsulated tumor (ie, one that is predominantly follieular with only a few papillary areas) and a weil-differentiated encapsulated follicular carcinoma. Either of these may be designated follicular carcinoma. To be meaningful, a classification must take into account the biologie behavior of a neoplasm as weil as its morphologie characteristies. Papillary Carcinoma
Papillary carcinoma is the most common form of malignant neoplasm of the thyroid, accounting for 60% to 70% of ail thyroid cancers. These tumors, occurring chiefly in young persans from the ages of puberty through 45 years, often develop a few years after radiation therapy for sorne benign condition of the head, neck, or chest. The tumors may be pure papillary, mixed follicular and papillary, or predominantly follicular with only a few papillary elements.
112
that the occurrence of distant metastasis is rare. lt is now weil established that neither total thyroidectomy nor radical neck dissection is often necessary in the treatment of papillary thyroid cancer. Morbidity can be avoided if total thyroidectomy is clone only when there is gross evidence of cancer bilaterally or bilateral involvement of lymph nades. When the disease is unilateral, total lobectomy on the affected side and removal of the isthmus and the major portion of the contralateral lobe, sparing enough of the thyroid capsule to support the parathyroids, are ail that is required. The conventional radical neck dissection is almost never· necessary, and results that are equal from the standpoint of cure can be obtained without sacrifice of the sternocleidomastoid muscle or 11 th nerve. In patients undergoing the modified neck dissection, there is no deformity of the neck. AU patients are given suppressive doses of desiecated thyroid as a prophylactic measure. Lymph nades involved in papillary thyroid cancer are usually those located behind the thyroid gland and extending dawn into the mediastinum. Less often, the lateral nades in the jugular chain are involved. Nodal metastases
POSTGRAOUATE MEDICINE • June 1975 • Vol. 57 • No. 7
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
may encase the recurrent laryngeal nerve but rarely are invasive. Sacrifice of the nerve at operation usually is unnecessary unless the larynx is paralyzed preoperatively. Transthoracic mediastinal dissection seldom is required because nades adhere ta each ether and can be removed through the neck incision. On rare occasions when previous operations on the neck have caused scarring, thoracotomy and open mediastinal dissection are necessary. At the Cleveland Clinic, these measures have been required in only two of about 600 patients undergoing operation for papillary thyroid carcinoma. The snowflake type of pulmonary metastasis which characterizes papillary carcinoma of the thyroid occasionally can be treated successfully with radioactive iodine, but use of this modality in cases of extensive pulmonary metastasis may cause excessive pulmonary fibrosis and death. We prefer ta give these patients suppressive doses of thyroid hormone, because a higher proportion will respond ta this form of therapy than ta radioactive iodine. Pulmonary metastasis can be treated by thyroid suppression alone. When a papillary carcinoma responds ta thyroid suppression, the favorable effect will persist for as long as the treatment is continued. I have never seen a papillary thyroid turner escape from hormonal suppression, as breast or prostatic cancer is known ta do. In a patient who has received radiation therapy, it is possible for a papillary carcinoma ta change into an undifferentiated carcinoma with a hopeless prognosis. The prognosis for survival of young patients with papillary carcinoma of the thyroid is good, their life expectancy following effective treatment being almost normal. A follow-up survey of 231 patients with papillary carcinoma treated at the Cleveland Clinic showed that only 2% of those who were traced for 5 ta 20 years had died of cancer, 1% were living with uncontrollable cancer, and 95% had lived for five years. Metastasis ta regional lymph nades was noted in 65% of the patients in the series, and pulmonary metastasis was demonstrable before operation in 4%. Thirteen percent underwent a
Vol. 57 • No. 7 • June 1975 • POSTGRADUATE MEDICINE
GEORGE CRILE, JR. Dr. Crile is in the department of general surgery, Cleveland Clinic, Cleveland.
secondary operation ta remove a contralateral node outside the field of the primary surgical procedure. A change in the ultimate prognosis related ta the overlooking of the nodal involvement in these cases was indiscernible. The deaths from cancer in the series were unrelated ta local recurrence or inability ta control the disease in the gland but were attributed ta systemic metastasis present at the time of operation or developing afterward. Most of the papillary thyroid carcinomas that occur in children and young adults with a history of radiation therapy are endocrine-dependent and will not grow if suppressive doses of desiccated thyroid are given. It is therefore unnecessary ta perform radical surgery in these young people, because once a remission of papillary carcinoma is established, it tends ta persist indefinitely. The surgeon should remove as much of the cancer as is possible without inflicting severe morbidity, such as tetany or nerve injury. Moreover, in a case with bilateral encasernent of the recurrent laryngeal nerve, a trial of suppressive therapy would be better than sacrifice of the nerve. The prognosis of papillary thyroid cancer is much less favorable in persans more than 50 years of age. The rare tall-cell variant of this neoplasm which occurs in aider persans can have a mortality rate as high as 30%. Angioinvasive Follicular Carcinoma
Encapsulated angioinvasive follicular carcinoma of the thyroid and its more serious vari-
113
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
ant, invasive adenocarcinoma, tend ta invade blood vessels and ta metastasize almost exclusively via the bloodstream, spreading ta the lungs and bane but seldom involving regional lymph nades. Fortunately, sorne of these metastatic lesions concentrate radioactive iodine avidly and can be controlled by administration of this substance after surgical removal of the thyroid lesion. These encapsulated tumors are almost never
Anaplastie carcinoma ofte·n is suspected clinically by its rapid growth, and the diagnosis is confirmed by aspiration biopsy.
multicentric. Grossly they resemble benign cellular adenomas, but microscopically they show invasion of blood vessels. A true benign adenoma is sharply encapsulated and cellular and has no invasive characteristics. An optimal prognosis for a patient with encapsulated follicular carcinoma of the thyroid is provided by complete removal of the affected lobe of the gland. Attempts ta perform total thyroidectomy and node dissection are useless and usually increase morbidity. lt is important, however, ta remove the turner with die capsule intact, preferably by lobectomy, sa turner tissue does not become implanted in the wound. When removal is complete, the prognosis is less favorable for a man than for a woman, especially if he is elderly. The more serious invasive adenocarcinomas tend ta occur in persans more than 50 years of age and carry a poor prognosis. Invasive Follicular Carcinoma
Invasive follicular thyroid carcinoma, a very lethal turner, grows slowly. Our follow-up survey showed that more than half of the patients
114
who died from this form of malignant turner survived for more than five years after operation. Whether or not an encapsulated angieinvasive follicular adenocarcinoma represents an early phase of an invasive follicular adenocarcinoma is difficult ta determine, but 1 doubt that it does. Analyses of cases of these types of follicular carcinoma taking into account the patients' age and sex and the duration of disease suggest that each is a separate entity and does not originate in another type of neoplasm. Although invasive follicular carcinoma grows slowly, and a patient with metastases may live for many years, our experience has shawn it ta be ultimately fatal, death usually being caused by systemic metastasis. Angioinvasion is a prominent histologie feature, and distant metastasis seems ta occur via the bloodstream before the diagnosis is made. Operations in these cases are chiefly palliative. If lymph nades are involved, they should be removed as simply as possible, along with the primary tumor, without adding the morbidity of a radical surgical procedure. Medullary (Solid) Carcinoma
Medullary (solid) thyroid carcinoma is a turner without an identifiable capsule, one that is undifferentiated in structure with individual cells that are regular and not anaplastie. This thyroid neoplasm frequently produces an amylaid stroma which is demonstrable with special stains. The turner is locally invasive and metastasizes bath ta the regionallymph nades and via the bloodstream. Although the majority of patients eventually succumb ta the disease, the lesion does tend ta grow slowly. Many of our patients have lived for five years or more after treatment. Treatment of medullary carcinoma is the same as treatment of papillary carcinoma of the thyroid, ie, nodal dissection and total lobectomy on the affected side, removal of the isthmus, and almost total removal of the lobe on the contralateral side, leaving the posterior capsule ta protect the parathyroids. 1 do not like ta perform total thyroidectomy unless there is bilateral nodal involvement or clinical evidence of bi-
POSTGRADUATE MEDICINE • June 1975 • Vol. 57 • No. 7
lateral involvement of the gland. The incidence of tetany after total thyroidectomy has been rather high at the Cleveland Clinic, but we have now almost eliminated permanent tetany by leaving an intact posterior capsule on the contralateral side. These tumors rarely recur on the contralateral side.
Downloaded by [Australian Catholic University] at 14:18 21 August 2017
Anaplastie Carcinoma
Anaplastie carcinoma of the thyroid is among the most malignant of tumors. The course of the disease from onset to death is usually less than a year and often is as short as four months. The tumor, usually occurring spontaneously in a persan 60 years of age or older, is characterized by local invasion and metastases to regional lymph nodes and to the lungs. Anaplastie carcinoma frequently is suspected clinically by its rapid growth, and the diagnosis confirmed by aspiration biopsy. Most of these lesions are inoperable when diagnosed, and the patients are best treated by aspiration biopsy and irradiation. Tissue damage resulting from surgical procedures causes the tumor to grow and systemic metastases to develop even more rapidly. Tracheostomy performed in the course of a radical operation allows the tumor to fungate into the trachea, with consequent bleeding and obstruction. Al-
though anaplastie carcinoma is not a radiosensitive tumor, irradiation may retard growth of the primary lesion and may be of palliative value until death occurs from systemic metastasis. Summary
Malignant lesions of the thyroid can be differentiated from benign tumors by cytologie examination of specimens removed by aspiration biopsy. To be meaningful, a classification of thyroid cancers must take into account the biologie behavior as well as the morphologie characteristics of the lesions. Papillary c;:ucinomas account for 60% to 70% of all thyroid cancers and metastasize primarily to regional lymph nodes. When the disease is unilateral, the operarive procedure recommended is total lobectomy on the affected side plus removal of the isthmus and a major portion of the contralateral lobe, sparing enough of the thyroid capsule to support the parathyroids. Total thyroidectomy and radical neck dissection are seldom indicated. Address reprint requests to George Crile, Jr., MD, Cleveland Clinic, 2020 E 93rd St, Cleveland, OH 44106. For ReadySource on thyroid management, see page 151. Summary self-test on thyroid management begins on page 144.
uest1on Match each type of thyroid cancer with one or more characteristics. 1. Invasive adenocarcinoma 2. Medullary carcinoma 3. Papillary carcinoma 4. Angioinvasive follicular carcinoma
d
a b, c
e, f
a. Tends to metastasize bath to regional lymph nod es and via the blood b. lnfrequently metastasizes to distant sites c. Nonencapsulated, does not resemble adenoma d. Tends to occur in persans over 50 years of age e. Metastasizes al most solely via bloodstream f. Encapsulated, grossly resembles adenoma
Vol. 57 • No. 7 • June 1975 • POSTGRADUATE MEDICINE
115
