Year : 2009 | Volume
: 52 | Issue : 2 | Page : 249--251
Large mammary hamartoma with focal invasive ductal carcinoma
Suneet K Pervatikar1, Ravikala Rao1, US Dinesh1, S Parameswaraiah2,
1 Department of Pathology, SDMCMSH, Dharwad, India
2 Department of Pathology, HIMS, Hassan, India
Suneet K Pervatikar
SDM College of Medical Sciences and Hospital, Manjushree Nagar, Dharwad - 580 009
Mammary hamartomas are uncommon benign lesions rarely associated with malignancy. We report a case of a 25-year-old female patient presenting with a lump in the left breast. Fine needle aspiration cytology showed features of invasive ductal carcinoma along with normal benign glands that were mistaken for normal breast tissue. However, the mastectomy specimen revealed the malignant mass within a larger hamartomatous mass. Mammary hamartomas are benign lesions but, on exceedingly rare occasions, they may be involved by incidental, coexisting carcinoma, as illustrated in this case report.
|How to cite this article:|
Pervatikar SK, Rao R, Dinesh U S, Parameswaraiah S. Large mammary hamartoma with focal invasive ductal carcinoma.Indian J Pathol Microbiol 2009;52:249-251
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Pervatikar SK, Rao R, Dinesh U S, Parameswaraiah S. Large mammary hamartoma with focal invasive ductal carcinoma. Indian J Pathol Microbiol [serial online] 2009 [cited 2020 Aug 9 ];52:249-251
Available from: http://www.ijpmonline.org/text.asp?2009/52/2/249/48935
Hamartomas are uncommon benign lesions composed of an admixture of fatty, fibrous connective tissue and glandular elements. Rarely, carcinomas arise within a hamartoma. Only 12 cases of carcinoma associated with hamartoma have been described in the literature.  This paper presents a case of a large, 15 × 10cm mammary hamartoma in a young, 25-year-old lady with an associated invasive ductal carcinoma (IDC).
A 25-year-old woman presented with a complaint of a lump in the left breast. The lump, on clinical examination, was in the upper outer quadrant of the left breast, measuring approximately 15 × 10cm. The lump was not attached to the skin or the underlying structures. The lump had gradually progressed to the present size. No nipple discharge was present. No other significant medical history was present.
Examination of the left axilla revealed a mobile lump measuring 1cm in diameter. No mammography was performed. The right breast on palpation revealed no lump.
FNAC was performed from three different sites. Two sites revealed benign ductal epithelial cells. FNAC from the third site showed large pleomorphic cells in small clusters, acini and singles, with a moderate amount of eosinophilic cytoplasm. Nuclei were round and hyperchromatic with irregular borders, some showing prominent nucleoli. The background showed hemorrhage. Diagnosis of IDC was made. FNAC from the ipsilateral axillary lymph node showed similar tumor cell deposits.
A radical mastectomy specimen was received measuring 33 × 28 × 8cm 3 . The external surface was unremarkable. A cut section showed a large well-circumscribed grayish white nodular rubbery mass measuring 12 × 6 × 6cm 3 . One area of the mass showed cystic change with dilated ducts containing greenish inspissated material. A yellowish ill-circumscribed nodule measuring 1.5cm in diameter was seen within this large mass [Figure 1]. A cut section of the nodule was homogenously yellow, with punctate areas of necrosis. Ten lymph nodes were isolated from the axillary tail, with the largest measuring 1cm in diameter.
Sections studied from the larger mass showed a well-circumscribed lesion composed of small lobules having few acini and ductules surrounded by intralobular stroma. Few ducts were dilated with cystic change. The fibrous stroma showed hyalinization [Figure 2a] and areas of pseudoangiomatous hyperplasia [Figure 2b]. Areas of entrapped adipose tissue were also seen [Figure 2c]. Features were indicative of a hamartoma breast.
The smaller mass within the larger mass showed tumor composed of large pleomorphic cells arranged in sheets and acini having scanty, eosinophilic cytoplasm and hyperchromatic irregular nuclei [Figure 3]. Numerous atypical mitotic figures were seen. Tumor cells were seen infiltrating the adjacent stroma of the hamartoma but not extending beyond the margins of the hamartoma. A focal area of necrosis was seen. Tumor emboli were seen in the lymphatics. Diagnosis of moderately differentiated IDC was made. Four of the 10lymph nodes isolated showed metastasis. Chemotherapy and radiotherapy were offered but were declined. No recurrence was seen after 1year of follow-up.
Breast hamartomas are uncommon, benign, slow growing lesions first reported by Arrigoni et al. in 1971.  These are also known as fibroadenolipomas. The reported incidence of breast hamartomas is 0.7% of benign breast tumors in females.  Clinically, they present as a painless slow growing mobile mass in the outer quadrant of the breast not attached to the underlying structures. They may even be impalpable, detected only on mammography. Clinically, they may be confused with fibroadenoma or phyllodes tumor. Patients are usually more than 35 years of age. Less than 10% present in the teenage. The size varies from 1 to 25cm 3 . Mammographically, they have a characteristic appearance consisting of a circumscribed mass of mixed fatty and soft tissue elements with a thin pseudocapsule and characteristic central lucency. 
Pathologically, they are grey to yellow well-circumscribed masses, smooth surfaced with a firm fleshy consistency. The lobulated appearance of the fibroadenoma is not seen. Microscopically, they have a pseudocapsule and are composed of a variable proportion of glandular, fibrous and adipose tissue.  Four morphological patterns have been described: encapsulated breast parenchyma with fibrocystic changes, fibroadenoma with fibroblastic stroma surrounding glandular structures, fibroadenoma like with normal lobules and circumscribed adenolipoma with adipose tissue containing scattered ducts and lobules.  These divisions have not been widely used because of the lack of any clinical and prognostic significance.
Microscopically, they should be distinguished from fibroadenoma. Both are well circumscribed but hamartomas have more fat, glands, lobules and less cellular stroma compared with fibroadenoma.  Epithelial hyperplasia is not a feature but cases of malignancy arising from mammary hamartoma have been reported. Of the 12 cases of hamartomas associated with malignancy, six patients had IDC. ,,, Of these six cases, two had coexisting ductal carcinoma in situ . ,
An additional two cases reported by Tse et al . had only ductal ca in situ , with foci of microinvasion in one of them. The remaining four cases had in situ and invasive lobular carcinoma.  It is expected that with increasing use of mammography or clinical screening more hamartomas will be recognized and diagnosed. The mean age for malignant cases is 62.4 years (32-78).  In 10 of the cases reported previously, patients were more than 50 years of age. In the case reported by Ruiz-Tovar et al. , the patient was 35 years old and in the other case reported by Tse, the patient was 32 years of age. In the present case, the patient was only 25 years old, indicating that malignancy should be ruled out in mammary hamartomas even in young patients. Malignancy in such a young age with coexisting hamartoma could be due to the associated genetic mutation, which was not sought in our case due to the lack of facilities.
Also, most of the cases of hamartoma were diagnosed on radiology (mammography) and malignancy was diagnosed later on. However, in the present case, IDC was diagnosed on cytology and hamartoma was diagnosed on gross specimen.
Treatment for benign cases is only lumpectomy. In cases associated with malignancy, the treatment protocol is the same as for other malignant tumors of the breast.
Hamartomas are uncommon lesions that are probably underdiagnosed. Malignancy in a hamartoma, just like in a fibroadenoma, is exceedingly rare (0.1%). This rare occurrence is illustrated by our case.
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