Dual Expression of Immunoglobulin Light Chains in Plasma Cell Myeloma: A Case Report and Literature Review.

Typically, myeloma cells express a monoclonal immunoglobulin (Ig), either heavy or light chain. Here, we present a case of multiple myeloma with clonal dual expression of kappa and lambda light chain in a 74-year-old woman. Awareness of rare biphenotypic myeloma is important for proper diagnostic workup. A 74-year-old woman underwent hip replacement with an incidental finding of 20% plasma cells in the femoral head. Subsequent bone marrow biopsy also showed about 30% of plasma cells negative for CD20, CD56, and CD117. Immunohistochemistry (IHC) and in situ hybridization studies showed a mixture of kappa and lambda plasma cells. Flow cytometry showed ambiguous results for cytoplasmic Ig light chains kappa and lambda. However, cyclin D1 was highly expressed by plasma cells, and increased free kappa light chains were identified in serum. Further investigation by double IHC demonstrated co-expression of kappa and lambda light chains in the same cells. Fluoresces in situ hybridization studies were positive for t(11;14)(q13;q32) and the deletion 13q. Since its first description by Taylor and Burns in 1974, the demonstration of restricted cytoplasmic Ig light chain expression by immunohistochemistry is 1 of the basic tools for corroborating clonality of the plasma cells in tissue biopsy. IHC results in myeloma with dual expression of Ig light chains may suggest polyclonal plasma cell population, especially when plasma cells do not form sheets in the bone marrow. In an appropriate clinical setting, other investigations are needed to exclude plasma cell neoplasm, even with seemingly "polytypic" results by IHC.

Massive gallstone in an asymptomatic Indigenous Canadian male: Case report and literature review.

INTRODUCTION: Gallstones are present in 10-15% of North Americans, but only 20% become symptomatic. This case report describes a patient with a 7.5 cm gallstone detected incidentally while being investigated for cardiac pathology. This is the first report in the English literature of a stone this size that has remained clinically asymptomatic. This work is reported in line with the SCARE criteria. CASE REPORT: The patient was a 71-year-old Indigenous Canadian male, with atrial fibrillation. His cardiologist ordered a CT scan of his chest, which incidentally identified a large gallstone. He was referred to surgery for asymptomatic cholelithiasis. An uncomplicated laparoscopic cholecystectomy was performed. Final pathology showed a 7.5 cm gallstone with features of chronic cholecystitis. DISCUSSION: The patient's ethnicity and gallstone size placed him at increased risk for gallbladder cancer, gallstone fistulization and perforation. We reviewed the literature for asymptomatic patients who may benefit from cholecystectomy: transplant recipients and those with hemolytic disorders. Laparoscopic cholecystectomy is not currently indicated in diabetics and bariatric surgery patients. CONCLUSION: This case report shows that there are asymptomatic patients with massive gallstones. A review of their history, risk factors for malignancy and future gallstone related complications must be carefully weighed and discussed prior to deciding on surgical versus expectant management.

De novo adolescent gastric carcinoma: a first case report in Saskatchewan, Canada.

Adolescent gastric cancers are extremely rare with a reported incidence of 0.05-0.10% in North America. We present a de novo case of gastric carcinoma in a 17-year-old teenager with no concomitant family history or risk factors. His main clinical presentation included anaemia and melaena stools. Despite an extensive clinical workup that included a diagnostic laparoscopy, the tumour was deemed surgically irresectable, and he was started on a palliative chemotherapy protocol at the local paediatric oncology centre. He demised 7 months later. This is the first recorded case of an adolescent gastric cancer in Saskatchewan, Canada. This case highlights the need for an international tumour registry to document and investigate rare adolescent gastric malignancies and thereby potentiate a possible cure through the pooling of limited resources.

Clear cell 'sugar' tumor of the breast: another extrapulmonary site and review of the literature.

A group of lesions show morphologic and immunophenotypic evidence of differentiation toward a putative perivascular epithelioid cell. These so-called PEComas include angiomyolipoma, lymphangiomyoma, lymphangioleiomyomatosis, renal capsuloma, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, and clear cell "sugar" tumor. PEComas are characterized by strong immunoreactivity with the HMB45 antibody and variable expression of muscle markers. This family of lesions may be composed of a spectrum of cells from epithelioid to spindle cells with clear to granular eosinophilic cytoplasm. One member of this family, composed of epithelioid cells with glycogen-rich clear cytoplasm, is descriptively called a clear cell "sugar" tumor. This tumor, originally described in the lung, is being recognized increasingly in extrapulmonary sites. We report a case of a primary extrapulmonary clear cell "sugar" tumor occurring in the right breast of a 16-year-old girl. The tumor was composed of clear epithelioid cells with abundant glycogen and distinct cell borders. The tumor showed strong immunoreactivity with HMB45 antibody and Melan-A. There was focal vimentin staining. In addition, there was diffuse and strong nuclear staining for progesterone receptor. Antibodies to actins, S-100 protein, cytokeratins (AE1/AE3 and CAM5.2), desmin, and estrogen receptor were negative. The tumor was completely excised, and the patient is well without evidence of disease 9 months postexcision.

Acinic cell carcinoma: an unusual cause of bronchial obstruction in a child.

Primary acinic cell carcinomas of the lung are rare tumors, usually presenting in adulthood as parenchymal or endobronchial masses. These lesions are generally recognized by their morphological pattern and the presence of periodic acid-Schiff (PAS)-positive, diastase-resistant cytoplasmic granules. We describe a case of pri-mary acinic cell carcinoma of the bronchus in a 4-year-old girl. The tumor has the typical acinar structures:weakly PAS-positive, diastase-resistant cytoplasmic granules and intra-acinar laminated calcific structures. A lobectomy was done with a clear bronchial resection margin. The child is well with no evidence of recurrence or metastasis 2 years postresection.