[Efficacy of serum immunoglobulin free light chain and 18F-FDG PET/CT for therapeutic evaluation in a case with multiple plasmacytoma of bone].

Solitary/multiple plasmacytoma of bone, a rare disease as compared to multiple myeloma, is characterized by monoclonal proliferation of plasma cells in local legion (s) of bone, with no bone marrow abnormalities. Monoclonal gammagloblinemia is often absent in these conditions, and useful examinations allowing evaluation of responses to treatment are as yet lacking. Recently, 18F-FDG PET/CT (PET/CT) was reported to be useful for detecting bone lesions. PET/CT is also valuable for predicting the outcomes of patients with solitary plasmacytoma, when applied in combination with the serum free light chain (sFLC) κ/λ ratio. We present a 62-year-old male with multiple plasmacytoma of bone (MPB), in whom PET/CT and the sFLC κ/λ ratio were useful for evaluating the response to treatment. The patient was diagnosed with MPB, with PET/CT showing multiple abnormal tracer uptakes in the scapula, spine, and ribs. The sFLC ratio was markedly elevated, with the κ chain level being especially high. We administered bortezomib and dexamethasone, after which the abnormal uptakes on PET/CT disappeared. The sFLC ratio and the FLC value also normalized, and have remained stable for more than one year, to date, since treatment. In our case, PET/CT and the sFLC κ/λ ratio were found to be extremely useful for monitoring treatment responses.

Metastatic breast cancer from gastric and ovarian cancer, mimicking inflammatory breast cancer: report of two cases.

Breast metastases from extra-mammary malignancies, especially those mimicking primary inflammatory breast carcinoma, are extremely rare. We report here two cases of inflammatory breast metastases from gastric or ovarian cancer. Both patients, who had prior advanced malignant disease, presented with unilateral breast redness and swelling with peau d'orange sign, resembling primary inflammatory breast cancer or acute mastitis. Breast biopsy revealed poorly differentiated adenocarcinoma with signet-ring cells or clear cell carcinoma in the lymphatic vessels and the parenchyma without an in situ lesion, similar to primary lesions of the stomach or ovary, respectively. Immunohistochemical staining for estrogen receptor, progesterone receptor, and gross cystic disease fluid protein 15 was of value for correct diagnosis. Since breast metastasis is a sign of poor prognosis of the primary malignant disease, the possibility of breast metastasis should be considered in appropriate patients to preclude unnecessary major surgery.

Breast signet-ring cell lobular carcinoma presenting with duodenal obstruction and acute pancreatitis.

We report here an extremely rare case of breast signet-ring cell carcinoma (SRCC) initially manifesting as duodenal metastasis and acute pancreatitis. A 62-year-old female presented with duodenal obstruction and swollen head of the pancreas, and the diagnosis of acute pancreatitis was initially made. Upper gastrointestinal endoscopy revealed duodenal stenosis with erosive mucosa, with signet-ring cells infiltrating the submucosal layer, suggesting duodenal metastasis of SRCC. Despite absence of a palpable mass in both breasts, computed tomography revealed diffuse enhancement of the left breast in addition to left axillary lymphadenopathy. Histological examination of mammary needle biopsy samples revealed SRCC with a non-invasive lobular carcinoma component. Primary breast SRCC with duodenal metastasis was therefore diagnosed. The patient underwent palliative surgery twice for intestinal obstruction due to peritoneal dissemination. She has remained alive without bowel obstruction for 18 months while being treated with cytotoxic chemotherapies.