Heterotopic breast tissue versus occult metastatic carcinoma in lymph node, a diagnostic dilemma

Breast cancer is the leading cause of cancer in women and the third leading cause of cancer mortality in the United States. We report a case of a patient who underwent bilateral simple mastectomies and right sentinel node biopsy for invasive lobular carcinoma in the right breast. An ipsilateral sentinel lymph node showed a microscopic focus of ductal elements. Although residual lobular carcinoma was identified in the right breast, no ductal carcinoma was identified in either breast. The ducts were discrete distributed in a 3-mm focus in the lymph node parenchyma as well as the subcapsular sinus. By immunohistochemistry, the ducts were positive for cytokeratin, estrogen receptor/progesterone receptor and did not show a myoepithelial layer by P63 or smooth-muscle myosin heavy-chain staining. The differential diagnosis includes heterotopic epithelial inclusions and benign mechanical transport. Mechanical transport of the breast tissue was ruled out because primary tumor type in the breast and the ductal structures in the lymph nodes were of different types. The diagnosis of occult metastatic tumor was based on the lack of the myoepithelial layers associated with the ductal structures. The diagnostic dilemma of the differential diagnoses is discussed, and pertinent literature is reviewed.

Supraclavicular failure after breast-conserving therapy in patients with four or more positive axillary lymph nodes when prophylactic supraclavicular irradiation is omitted

PURPOSE

The incidence of supraclavicular metastasis as the initial failure and the failure patterns in patients with four or more positive axillary lymph nodes (PALNs) after breast-conserving therapy (BCT) without prophylactic supraclavicular irradiation were investigated.

MATERIALS AND METHODS

Between 1991 and 2002, a total of 48 women with four or more PALNs underwent BCT without prophylactic supraclavicular irradiation (33 patients with 4-9 PALNs; 15 patients with > or =10 PALNs).

RESULTS

The median follow-up time was 50 months. Among the patients with 4-9 PALNs, 3% had isolated supraclavicular metastasis as the initial failure, and 30% had distant metastasis as the initial failure. Among patients with > or =10 PALNs, 7% had isolated supraclavicular metastasis as the initial failure, and 40% had distant metastasis as the initial failure. The 4-year isolated supraclavicular failure rates were 5% for all patients, 3% for patients with 4-9 PALNs, and 8% for patients with >/=10 PALNs.

CONCLUSION

In patients who had undergone BCT and had had four or more PALNs, the major failure pattern was distant failure with or without locoregional failure; isolated supraclavicular failure as the initial failure comprised a less common failure pattern. Omission of prophylactic supraclavicular irradiation may be acceptable for this subset of patients.