Hamartoma of the Breast: Diagnostic Observation of 16 Cases 1
Diagnostic Radiology
Christian Hessler, M.D., Pierre Schnyder, M.D., and Luciano Ozzello, M.D. Of 10,000 mammographies done over a 9-year period, 16 cases of hamartoma of the breast were diagnosed. The entity is a well delimited mass composed of dysplastic-appearing mammary tissue admixed to fat. It can be readily recognized and should not be confused with fibroadenoma or mammary dysplasia. The accuracy with which it can be diagnosed by mammography makes possible the avoidance of surgical excision in selected patients. INDEX TERMS:
Breast, diseases • Breast, neoplasms. (Breast, other benign neoplasm,
0[0].3199) Radiology 126:95-98, January 1978 AMARTOMAS OF THE BREAST are grossly circumscribed
H
masses composed of mammary ducts and lobules admixed to varying amounts of fibrous and adipose tissue. The clinical and pathological features (1) and mammographic appearance (6) have been previously described. This entity is still little known, however, and is frequently misdiagnosed as a fibroadenoma or mammary dysplasia. We wish to discuss the mammographic and pathological diagnostic criteria of this lesion, and to underscore the accuracy with which it can be recognized by routine mammography. MATERIALS AND METHODS
This study is based on 16 cases diagnosed radiographically by one of us (C.H.) out of 10,000 consecutive mammographies performed from 1967 to 1976. This is not a retrospective study; the diagnoses were made on the first examination of the mammographic images. The patients ranged in age from 27 to 88 years, with a mean of 45. Most had been pregnant. Their only complaint was the presence of a mass noticed variably from as little as a few days up to as long as 15 years before. The size of the masses varied from 3 to 13 em in greatest dimension. They were not confined to any particular location in the breast: 10 of them were so large as to occupy more than one quadrant. On physical examination they appeared as a dominant lump whose consistency was not much different from that of the adjacent breast tissue. For this reason they were frequently felt only after their location had been made evident by the images.
Fig. 1. A 50-year-Old multipara woman had a soft large lump on the outer aspect of the right breast. Mammography shows a typical hamartoma with a predominance of fat (9 X 5.5 em).
RADIOLOGICAL ASPECTS
Although the clinical presentation of a mammary hamartoma may not be impressive, its radiological appearance is generally quite striking, especially because the lesion appears to be completely separate from the remainder of the breast. It has a circular configuration and 1
gives the impression of being surrounded by a "capsule." The distribution of the glandular structures within the lesion is irregular and contrasts sharply with the adjacent
From the Departments of Radiology and Pathology, University of Lausanne, Switzerland. Accepted for publication in August, 1977.
95
ss
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January 1978
CHRISTIAN HESSLER AND OTHERS
3). This is true even when the hamartoma is very large and occupies two thirds or more of the breast volume. Sometimes the lesion replaces the subcutaneous fat that normally separates the skin from the mammary tissue. Under these circumstances the hamartoma comes in contact with the epidermis without producing the cutaneous alterations often caused by superficially located carcinomas. THERMOGRAPHIC ASPECTS
The thermographic appearance is quite variable. Some lesions are hypothermic, while others are hyperthermic. Many of them do not perturb the thermographic image. We could not find any relationship between the thermographic appearance and the relative quantities of fat and parenchyma in the lesion. PATHOLOGICAL ASPECTS
Fig. 2. A 69-year-old nullipara woman had a lump on the outer upper quadrant of the right breast. Mammography shows a large typical hamartoma with predominance of parenchyma.
breast architecture. While mammary tissue, even when dysplastic, generally retains a triangular, nipple-oriented type of structure, the hamartoma is completely devoid of this architecture, and is therefore quite evident at first glance. The degree of opacity is variable and depends on the fat/parenchyma ratio. Some hamartomas have little parenchyma, and are consequently very radiolucent and may be confused with lipomas (Fig. 1). Most of our cases were rich in parenchyma, the glandular tissue being 3 to 5 times more abundant than fat, and were therefore fairly dense (Fig. 2). There is sometimes so little adipose tissue that the lesion could be mistaken for a fibroadenoma. Our hamartomas, however, never had a consistency as hard as that of fibroadenomas, even when they were composed mostly of glandular tissue. The hamartoma does not replace breast tissue: rather it pushes the normal parenchyma aside and is sometimes separated from it by a thin radiolucent zone as seen in other benign mammary conditions. It is of interest to remark that after the removal of a hamartoma, the breast tissue reexpands and again becomes symmetric and normal-appearing both clinically and radiologically (Fig.
Pathologically, the hamartoma of the breast can be best described as a well delimited mass of dysplastic-appearing mammary tissue. Grossly (Fig. 4), it is circumscribed and surrounded by a thin layer of fibrous tissue. Its cut surface is irregular and shows a variable admixture of adipose and fibrous tissue in which the glandular elements are located. The adipose tissue is very abundant in some, suggesting the macroscopic diagnosis of lipoma. Cysts of varying dimensions are sometimes visible. Slit-like spaces as seen in fibroadenomas are missing. Histologically (Fig. 5), the whole spectrum of dysplastic lesions is displayed. The ductal and lobular architecture is well recognizable although often altered to varying extents. No atypical hyperplasias were seen in any of our cases. When the entire lesion is excised, therefore, the hamartoma is easily distinguished from the fibroadenoma and from mammary dysplasia. On the other hand, if only an incisional biopsy is available and no information is given as to the sharp delimitation of the lesion, the pathologist may be Ied to the erroneous diagnosis of mammary dysplasia. DISCUSSION
When a surgeon palpates a rather soft nodule of the breast and excises a well-circumscribed ("encapsulated") lesion suggestive of a fibroadenoma, he is sometimes surprised to read the pathological report mentioning an unusual type of mammary dysplasia. A not too rare but poorly known lesion may be the correct diagnosis: mammary hamartoma. It is surprising that this lesion is so little known. In all likelihood many cases have been operated upon during the last decades. Furthermore, one can find descriptions of probably the same entity under different names such as adenolipoma (3-5, 9), fibroadenolipoma (6), and postlactational breast tumor (7). The term hamartoma, proposed by Arrigoni et al. (1),
Vol. 126
HAMARTOMA OF THE BREAST
97
Diagnostic Radiology
Fig. 3. A. A 27-year-old unipara woman had a lesion of the right breast palpable for a year. Mammography shows a typical hamartoma rich in parenchyma. B. Control mammography of the same breast 3 years after surgery shows that the breast tissue has reexpanded and looks now normal.
appears to us as the most appropriate. There is certainly no pathogenetic relationship between lactation and this lesion. Furthermore, it is difficult to visualize a mammary dysplasia becoming so well circumscribed and separate from the remainder of the breast parenchyma. The fibroadenoma also cannot be likened to the hamartoma due to its different histological make-up and age incidence. Our cases were found either after a pregnancy or more often after the menopause. This leads us to suspect that mammary hamartomas may develop within the breast as hamartomas of other organs, to become palpable when the rest of the breast undergoes an involution, as in the post-
partum period or after the menopause, or following a substantial weight loss. The radiologist is frequently the first to be able to recognize this lesion and advise the surgeon and the pathologist in advance. An excisional biopsy, which generally can be accomplished without difficulty, appears to us preferable to an incisional biopsy. Receiving the lesion intact, the pathologist is then in the position of recognizing the hamartoma macroscopically and to confirm it histologically. The mammographic appearance of mammary hamartomas being so distinctive, excision may not be necessary for selected patients presenting a clear picture
98
CHRISTIAN HESSLER AND OTHERS
Fig. 4. Gross appearance of a hamartoma of the breast. The lesion is well delimited and shows an irregular cut surface.
of this lesion and suffering no particular discomfort.
REFERENCES 1. Arrigoni MG, Dockerty MB, Judd ES: The identification and treatment of mammary hamartoma. Surg Gynecol Obstetr 133:577582, Oct 1971 2. Cuttler M: Tumors of the Breast: Their Pathology, Symptoms, Diagnosis and Treatment. Lippincott, Philadelphia, 1962, pp 33-36 3. Durso EA: Mammographic findings in adenolipoma. JAMA 218:886,8 Nov 1971 4. Dyreborg U, Starklint H: Adenolipoma mammae. Acta Radiol 16:362-366, 1975 5. Haagensen CD: Diseases of the Breast. Saunders, Philadelphia, 2d ed, 1971, pp 307-308
January 1978
Fig. 5. Peripheral portion of a mammary hamartoma. Notice the sharp delimitation from the surrounding tissue, the dysplastic appearance of ducts and lobules, and the presence of adipocytes (H and E X 50).
6. Hoeffken W, Lanyi M: ROentgen Untersuchung der Brust. Georg Thieme Verlag, Stuttgart, 1973, pp 117-119 7. Hageman KE, Ostberg G: Three cases of postlactational breast tumor of a peculiar type.Acta Pathol Microbiol Scand 73:169-176, 1968 8. Puente Duany N: Hiperplasia adenofibrolipomatosa 0 fibrolipomatosis periglandular de aspeto tumoral de la mama. Arch Cuban Cancer 17:361-367, 1958 9. SpaldingJE: Adena-lipoma and lipoma of the breast. Guys Hasp Rep 94:80-89, 1945
Department of Radiology Medical School University of Lausanne Lausanne, Switzerland
Diagnostic Radiology
Christian Hessler, M.D., Pierre Schnyder, M.D., and Luciano Ozzello, M.D. Of 10,000 mammographies done over a 9-year period, 16 cases of hamartoma of the breast were diagnosed. The entity is a well delimited mass composed of dysplastic-appearing mammary tissue admixed to fat. It can be readily recognized and should not be confused with fibroadenoma or mammary dysplasia. The accuracy with which it can be diagnosed by mammography makes possible the avoidance of surgical excision in selected patients. INDEX TERMS:
Breast, diseases • Breast, neoplasms. (Breast, other benign neoplasm,
0[0].3199) Radiology 126:95-98, January 1978 AMARTOMAS OF THE BREAST are grossly circumscribed
H
masses composed of mammary ducts and lobules admixed to varying amounts of fibrous and adipose tissue. The clinical and pathological features (1) and mammographic appearance (6) have been previously described. This entity is still little known, however, and is frequently misdiagnosed as a fibroadenoma or mammary dysplasia. We wish to discuss the mammographic and pathological diagnostic criteria of this lesion, and to underscore the accuracy with which it can be recognized by routine mammography. MATERIALS AND METHODS
This study is based on 16 cases diagnosed radiographically by one of us (C.H.) out of 10,000 consecutive mammographies performed from 1967 to 1976. This is not a retrospective study; the diagnoses were made on the first examination of the mammographic images. The patients ranged in age from 27 to 88 years, with a mean of 45. Most had been pregnant. Their only complaint was the presence of a mass noticed variably from as little as a few days up to as long as 15 years before. The size of the masses varied from 3 to 13 em in greatest dimension. They were not confined to any particular location in the breast: 10 of them were so large as to occupy more than one quadrant. On physical examination they appeared as a dominant lump whose consistency was not much different from that of the adjacent breast tissue. For this reason they were frequently felt only after their location had been made evident by the images.
Fig. 1. A 50-year-Old multipara woman had a soft large lump on the outer aspect of the right breast. Mammography shows a typical hamartoma with a predominance of fat (9 X 5.5 em).
RADIOLOGICAL ASPECTS
Although the clinical presentation of a mammary hamartoma may not be impressive, its radiological appearance is generally quite striking, especially because the lesion appears to be completely separate from the remainder of the breast. It has a circular configuration and 1
gives the impression of being surrounded by a "capsule." The distribution of the glandular structures within the lesion is irregular and contrasts sharply with the adjacent
From the Departments of Radiology and Pathology, University of Lausanne, Switzerland. Accepted for publication in August, 1977.
95
ss
96
January 1978
CHRISTIAN HESSLER AND OTHERS
3). This is true even when the hamartoma is very large and occupies two thirds or more of the breast volume. Sometimes the lesion replaces the subcutaneous fat that normally separates the skin from the mammary tissue. Under these circumstances the hamartoma comes in contact with the epidermis without producing the cutaneous alterations often caused by superficially located carcinomas. THERMOGRAPHIC ASPECTS
The thermographic appearance is quite variable. Some lesions are hypothermic, while others are hyperthermic. Many of them do not perturb the thermographic image. We could not find any relationship between the thermographic appearance and the relative quantities of fat and parenchyma in the lesion. PATHOLOGICAL ASPECTS
Fig. 2. A 69-year-old nullipara woman had a lump on the outer upper quadrant of the right breast. Mammography shows a large typical hamartoma with predominance of parenchyma.
breast architecture. While mammary tissue, even when dysplastic, generally retains a triangular, nipple-oriented type of structure, the hamartoma is completely devoid of this architecture, and is therefore quite evident at first glance. The degree of opacity is variable and depends on the fat/parenchyma ratio. Some hamartomas have little parenchyma, and are consequently very radiolucent and may be confused with lipomas (Fig. 1). Most of our cases were rich in parenchyma, the glandular tissue being 3 to 5 times more abundant than fat, and were therefore fairly dense (Fig. 2). There is sometimes so little adipose tissue that the lesion could be mistaken for a fibroadenoma. Our hamartomas, however, never had a consistency as hard as that of fibroadenomas, even when they were composed mostly of glandular tissue. The hamartoma does not replace breast tissue: rather it pushes the normal parenchyma aside and is sometimes separated from it by a thin radiolucent zone as seen in other benign mammary conditions. It is of interest to remark that after the removal of a hamartoma, the breast tissue reexpands and again becomes symmetric and normal-appearing both clinically and radiologically (Fig.
Pathologically, the hamartoma of the breast can be best described as a well delimited mass of dysplastic-appearing mammary tissue. Grossly (Fig. 4), it is circumscribed and surrounded by a thin layer of fibrous tissue. Its cut surface is irregular and shows a variable admixture of adipose and fibrous tissue in which the glandular elements are located. The adipose tissue is very abundant in some, suggesting the macroscopic diagnosis of lipoma. Cysts of varying dimensions are sometimes visible. Slit-like spaces as seen in fibroadenomas are missing. Histologically (Fig. 5), the whole spectrum of dysplastic lesions is displayed. The ductal and lobular architecture is well recognizable although often altered to varying extents. No atypical hyperplasias were seen in any of our cases. When the entire lesion is excised, therefore, the hamartoma is easily distinguished from the fibroadenoma and from mammary dysplasia. On the other hand, if only an incisional biopsy is available and no information is given as to the sharp delimitation of the lesion, the pathologist may be Ied to the erroneous diagnosis of mammary dysplasia. DISCUSSION
When a surgeon palpates a rather soft nodule of the breast and excises a well-circumscribed ("encapsulated") lesion suggestive of a fibroadenoma, he is sometimes surprised to read the pathological report mentioning an unusual type of mammary dysplasia. A not too rare but poorly known lesion may be the correct diagnosis: mammary hamartoma. It is surprising that this lesion is so little known. In all likelihood many cases have been operated upon during the last decades. Furthermore, one can find descriptions of probably the same entity under different names such as adenolipoma (3-5, 9), fibroadenolipoma (6), and postlactational breast tumor (7). The term hamartoma, proposed by Arrigoni et al. (1),
Vol. 126
HAMARTOMA OF THE BREAST
97
Diagnostic Radiology
Fig. 3. A. A 27-year-old unipara woman had a lesion of the right breast palpable for a year. Mammography shows a typical hamartoma rich in parenchyma. B. Control mammography of the same breast 3 years after surgery shows that the breast tissue has reexpanded and looks now normal.
appears to us as the most appropriate. There is certainly no pathogenetic relationship between lactation and this lesion. Furthermore, it is difficult to visualize a mammary dysplasia becoming so well circumscribed and separate from the remainder of the breast parenchyma. The fibroadenoma also cannot be likened to the hamartoma due to its different histological make-up and age incidence. Our cases were found either after a pregnancy or more often after the menopause. This leads us to suspect that mammary hamartomas may develop within the breast as hamartomas of other organs, to become palpable when the rest of the breast undergoes an involution, as in the post-
partum period or after the menopause, or following a substantial weight loss. The radiologist is frequently the first to be able to recognize this lesion and advise the surgeon and the pathologist in advance. An excisional biopsy, which generally can be accomplished without difficulty, appears to us preferable to an incisional biopsy. Receiving the lesion intact, the pathologist is then in the position of recognizing the hamartoma macroscopically and to confirm it histologically. The mammographic appearance of mammary hamartomas being so distinctive, excision may not be necessary for selected patients presenting a clear picture
98
CHRISTIAN HESSLER AND OTHERS
Fig. 4. Gross appearance of a hamartoma of the breast. The lesion is well delimited and shows an irregular cut surface.
of this lesion and suffering no particular discomfort.
REFERENCES 1. Arrigoni MG, Dockerty MB, Judd ES: The identification and treatment of mammary hamartoma. Surg Gynecol Obstetr 133:577582, Oct 1971 2. Cuttler M: Tumors of the Breast: Their Pathology, Symptoms, Diagnosis and Treatment. Lippincott, Philadelphia, 1962, pp 33-36 3. Durso EA: Mammographic findings in adenolipoma. JAMA 218:886,8 Nov 1971 4. Dyreborg U, Starklint H: Adenolipoma mammae. Acta Radiol 16:362-366, 1975 5. Haagensen CD: Diseases of the Breast. Saunders, Philadelphia, 2d ed, 1971, pp 307-308
January 1978
Fig. 5. Peripheral portion of a mammary hamartoma. Notice the sharp delimitation from the surrounding tissue, the dysplastic appearance of ducts and lobules, and the presence of adipocytes (H and E X 50).
6. Hoeffken W, Lanyi M: ROentgen Untersuchung der Brust. Georg Thieme Verlag, Stuttgart, 1973, pp 117-119 7. Hageman KE, Ostberg G: Three cases of postlactational breast tumor of a peculiar type.Acta Pathol Microbiol Scand 73:169-176, 1968 8. Puente Duany N: Hiperplasia adenofibrolipomatosa 0 fibrolipomatosis periglandular de aspeto tumoral de la mama. Arch Cuban Cancer 17:361-367, 1958 9. SpaldingJE: Adena-lipoma and lipoma of the breast. Guys Hasp Rep 94:80-89, 1945
Department of Radiology Medical School University of Lausanne Lausanne, Switzerland
