Paget's disease of the nipple.

Paget's disease of the breast is a disorder of the nipple-areola complex that, while rare, is often associated with an underlying carcinoma. It is characterized by eczematoid changes of the nipple. Two theories have been proposed to explain the pathogenesis of Paget's disease. The Epidermotropic, which is the most accepted theory, suggests that Paget's cells originate from ductal cancer cells that had migrated from the underlying breast parenchyma. It is supported by the predominance of breast cancer markers found in Paget's disease. This article provides an overview of Paget's disease of the breast with special attention to immunohistochemistry and raises the question of new therapeutic approaches.

Multiple receptor conversions during the course of metastatic breast cancer therapy: a case report and review of the literature.

BACKGROUND: Adjuvant systemic therapy decreases recurrence and death from breast cancer, but late relapse still occurs. Therapeutic decisions are based heavily on receptor tissue characterization. Even though the vast majority of metastatic sites do not have receptor conversions, they can occur at the time of metastasis and/or during the course of treatment. However, multiple receptor conversions are uncommon. CASE PRESENTATION: We present an unusual case of a Caucasian patient originally diagnosed with an estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor 2-negative primary breast cancer who had a recurrence after 15 years of therapy. Her metastatic tumor had a different receptor status than the original tumor. During the course of therapy, at the time of progression, a new biopsy showed that her tumor had changed once more. CONCLUSION/DISCUSSION: Tracking receptor conversions is important in metastatic breast cancer treatment. Single receptor conversions have been documented to occur, but not much is known of multiple receptor conversions. This case sheds light on the possibility of patients having multiple receptor conversions and the importance of performing multiple biopsies during the course of metastatic treatment.

Rosai-Dorfman disease of the central nervous system: report of 6 cases and review of the literature.

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is an uncommon benign idiopathic lymphoproliferative disorder. The histologic hallmark of RDD is the finding of emperipolesis displayed by lesional histiocytes. While RDD most commonly affects lymph nodes, extranodal involvement of multiple organs has been reported, including the central nervous system (CNS). However, CNS involvement in RDD is rare and is not well characterized. As a result, therapeutic approaches to CNS involvement in RDD are not well established. Herein we report 6 cases of RDD with isolated CNS involvement and review the literature on RDD with CNS involvement. One of the presented cases exhibited intramedullary involvement of the spinal cord--a very rare form of RDD with CNS involvement.