Ancient Schwannoma of the Thigh: Metaplastic Ossification, Cartilage Formation, and Extensive Calcification.

Benign soft tissue masses that present with atypical features on imaging may erroneously be diagnosed as malignant processes. An ancient schwannoma, a schwannoma variant with pronounced degenerative features, is one possible etiology of an incidental soft tissue tumor. This case report describes a 69-year-old male with a history of lung carcinosarcoma who presented to the orthopedic oncology office following an incidental positron emission tomography-computed tomography (PET-CT) finding of a posterior, lateral thigh mass with extensive calcifications. Subsequent excision and pathological analysis revealed an ancient schwannoma with advanced degenerative features, including metaplastic bone and cartilage formation. Various degenerative changes may typically be identified with pathological analysis. In addition to the degenerative findings on pathological analysis, our case highlights an atypical instance where extensive calcification and ossification are evident radiographically. This case emphasizes the importance of considering ancient schwannoma when a calcified soft tissue mass is encountered, in addition to the list of more common calcified soft tissue masses.

The Role of the Duffy Blood Group Antigens in Renal Transplantation and Rejection. A Mini Review.

Finding a compatible donor for kidney transplant candidates requires overcoming immunological barriers such as human leukocyte antigens (HLA) compatibility and ABO compatibility. Emerging data suggest a role for red blood cell antigens (RCA) in renal transplant outcomes. The incidence of RCA alloimmunization is high in chronically transfused individuals, such as end stage renal disease patients, but whether antibodies to RCA can mediate renal graft rejection remains debatable. The Duffy blood group antigens (Fy) has been shown to be expressed in the kidney, among other tissues. There are some data to suggest that donor-recipient Fy mismatches may increase the risk for chronic allograft damage and that anti-Fy antibodies may be involved in renal graft rejection, however, while it is routine to screen renal transplant candidates for ABO antigens, detailed RCA phenotyping of the donor kidney is not routinely tested. In this paper, we review the current data on the role of Fy in renal transplantation and discuss the potential mechanisms of its biological function.

A Case of TFE3-positive Non-neoplastic Pseudodecidualized Endometrium Presenting as a Cervical Mass.

Transcription factor E3 (TFE3) represents a useful target for immunohistochemistry assays in routine surgical pathology practice. This protein has shown nuclear expression in a variety of normal tissues; however, this expression is usually at very low levels, while strong nuclear immunoreactivity of TFE3 has been seen almost exclusively in tumors. We present the case of a 30-year-old female on oral contraceptive pill (drospirenone/ethinylestradiol) and with complaints of dysmenorrhea and menorrhagia. She was found to have a cervical mass on pelvic ultrasound, and the biopsy showed fragments of benign squamous epithelium and polypoid endometrial tissue with stromal pseudodecidualization and abundant mixed inflammation. The pseudodecidualized stromal component showed moderate to strong nuclear staining in ~85% of stromal cells for TFE3. We discuss the intracellular role of TFE3 during inflammatory states and hypothesize that TFE3 expression can be associated with ongoing inflammation. Our case shed light upon the possibility that non-neoplastic environments with an inflammatory background could lead to increased nuclear expression of TFE3. Pathologists should be aware of the possibility of strong nuclear expression of TFE3 in non-neoplastic endometrium to avoid potential misdiagnosis.

Late onset ipilimumab-induced pericarditis and pericardial effusion: a rare but life threatening complication.

Metastatic cutaneous melanoma has poor prognosis with 2-year survival rate of 10-20%. Melanoma cells express various antigens including gp100, melanoma antigen recognized by T cells 1 (MART-1), and tyrosinase, which can induce immune-mediated anticancer response via T cell activation. Cytotoxic T-lymphocyte associated antigen-4 (CTLA-4) is an immune check point molecule that negatively regulates T cell activation and proliferation. Accordingly, recent phase III clinical trials demonstrated significant survival benefit with ipilimumab, a human monoclonal antibody (IgG1) that blocks the interaction of CTLA-4 with its ligands. Since the efficacy of ipilimumab depends on T cell activation, it is associated with substantial risk of immune mediated adverse reactions such as colitis, hepatitis, thyroiditis, and hypophysitis. We report the first case of late onset pericarditis and cardiac tamponade associated with ipilimumab treatment in patient with metastatic cutaneous melanoma.