Journal of Cancer Research and Therapeutics Medknow Publications on behalf of the Association of Radiation Oncologists of India (AROI) ISSN: 0973-1482 EISSN: 1998-4138 Vol. 5, Num. 4, 2009, pp. 321-323

Journal of Cancer Research and Therapeutics, Vol. 5, No. 4, October-December, 2009, pp. 321-323

Case Report

Rectal carcinoma metastasizing to the breast: A case report and review of literature

Singh Tejinder, Premalatha CS, Satheesh CT, Lakshmaiah KC, Suresh TM, Babu KGovind, Ramachandra C

Department of Medical Oncology, Kidwai Memorial Institute of Oncology, Bangalore-560 030

Correspondence Address:Department of Medical Oncology, Kidwai Memorial Institute of Oncology, Bangalore- 560 029
drtejinderseera@ gmail.com

Code Number: cr09078

PMID: 20160374

Abstract

Keywords: Breast metastasis, immunohistochemistry, rectal carcinoma

Introduction

Metastases in the breast from an extramammary primary is uncommon and, according to clinical reports, constitute approximately 1.2-2% of all breast metastases, although the incidence at autopsy is reported to be up to 6.6%. ^[1],[2] Approximately 300 cases of breast metastases from extramammary sites have been reported, mostly in small series or as single cases. The vast majority of extramammary breast metastases originate from melanomas, rhabdomyosarcomas, lung, ovary, and prostate in males (excluding lymphoma/leukemia). ^[3],[4],[5] They are usually seen in the reproductive age-group (30-45 years) and present as solitary well-defined lesions, usually in the upper outer quadrant. Metastases from gastrointestinal malignancies, such as esophageal, gastric, and colorectal primaries, are much less frequent. Breast metastases from colorectal carcinoma have been described previously in a small number of cases in the literature. ^[6],[7],[8]

Here, we report a case of metastasis to the breast from a previous rectal carcinoma and discuss the features differentiating metastatic rectal cancer from primary breast cancer.

Case Report

A 42-year-old woman presented with a 2 month history of a breast lump discovered incidentally by the patient. She had no increased risk factors for breast cancer, hormonal or familial. Eleven months earlier she had undergone an anterior resection for a stage T4N1M0 (Dukes stage C2) rectal carcinoma in another hospital, followed by chemo-radiation and subsequent chemotherapy. She also complained of bodyache, loss of appetite, fatigue, and dyspnea. On examination, her general condition was poor and she had tachycardia. Physical examination revealed 5 × 4 cm lump in the upper outer quadrant of the right breast, without evidence of axillary and supraclavicular lymphadenopathy. The contralateral breast and axilla were normal. Respiratory system examination revealed bilateral pleural effusion.

Mammograms showed a well-defined mass lesion that was not obviously malignant. Fine needle aspiration cytology (FNAC) was suspicious of malignancy. Pleural fluid cytology showed metastatic adenocarcinoma. Core needle biopsy of the breast lesions was performed and tissue was sent for histological examination. It revealed signet-ring cell carcinoma infiltrating the fat and fibrous tissue, with few preserved normal ducts and lobules [Figure - 1] and [Figure - 2]. No in situ carcinoma was noted. An immunohistochemistry study on the core biopsy specimens was positive for CK 20 [Figure - 3] and negative for CK 7, estrogen receptor, and progesterone receptor, which is typical of a rectal cancer primary. Histopathology slides of previous surgery were also sent for review, which showed mucin-secreting adenocarcinomas with signet ring cells infiltrating the full thickness of the rectum [Figure - 4]. The serum carcinoembryonic antigen (CEA) levels were mildly elevated. Biochemical parameters were normal. An ultrasound examination of the liver showed no abnormality at presentation.

The patient subsequently developed a liver metastasis and then became less well and complained of headaches. A computed tomographic scan demonstrated metastases in the brain. She deteriorated rapidly, becoming too unwell to receive intended cranial irradiation, and died 2 months after presenting with the breast mass.

Review of the Literature

Breast secondaries from a colorectal primary neoplasm are extremely rare. Only 10 such instances have been reported in the literature, two of them being in men. ^[6],[7],[8] It can occur as synchronous lesions or may follow the primary by months to years. The correct diagnosis is therefore crucial in these patients so that unnecessary surgical interventions can be avoided. These metastatic lesions must be differentiated from primary breast tumors on the basis of history, clinical and radiological features, morphology of the tumor (which resembles the primary tumor), and IHC findings.

Features favoring metastases are the following :

• Atypical or unusual histology
• Well-circumscribed tumor with periductal and perilobular distribution
• Absence of in situ carcinoma
• Multiple satellite foci in addition to the main mass
• Many lymphatic tumor emboli
• Immunohistochemistry negative for CK 7 and hormone receptors

For our patient the diagnosis was finally reached after studying the pattern of cytokeratins (CK) expression. Expression of CK7 and CK20 is considered to be most helpful in identifying the origin of adenocarcinomas whose morphological features do not allow specifying the initial origin in this algorithm. Some tumors (e.g., renal) express none of these cytokeratins, while some (mucinous ovarian carcinoma, pancreatic carcinoma, and transitional cell carcinoma of the bladder) express both cytokeratins. Importantly, the great majority of breast tumors are CK7-positive and CK20-negative, while colorectal carcinomas are usually CK7-negative and CK20-positive. ^[9] By combining the results of CK 20/7 and ER/PR staining, all the metastases to the breast could be properly classified in one study.

Metastatic disease in the breast is a marker for disseminated metastatic spread, and therefore indicates a poor prognosis. Metastases to the breast are rare in themselves, and such metastases occurring secondary to a previous rectal carcinoma makes this case very unusual. The local lymph nodes, liver, and lungs are the usual initial sites of spread of colorectal cancers; disseminated metastases with sparing of these organs is unlikely but possible. In our patient, the breast deposit was the first clinical indication of relapse. A history of previous malignancy is most important in making a diagnosis of metastasis to the breast.

References

Copyright 2009 - Journal of Cancer Research and Therapeutics

The following images related to this document are available:

Photo images