Checkpoint inhibitor therapy with monoclonal antibodies against programmed cell death protein 1 (PD1) has been implemented in the treatment of numerous malignancies. Pembrolizumab is one such medication. While severe toxicities are very rare, mild immune-mediated reactions with a variety of end organ injuries are among the most commonly encountered adverse events attributed to these medications. Acute liver injury manifesting as biochemical abnormalities with or without synthetic dysfunction is one such potential adverse reaction. Rarely, a relatively severe hepatitis can occur. While such severe adverse events are often successfully managed with systemic corticosteroids and drug discontinuation, our patient was refractory to standard management. We present a case of pembrolizumab-induced hepatitis in a patient with squamous cell carcinoma and prior orthotopic liver transplantation. Through a combination of serial plasmapheresis and intravenous immunoglobulin(IVIG) infusion, the patient’s hepatitis resolved as evidenced by virtual normalization of his liver indices. This illustrates the effectiveness of a relatively novel treatment strategy for this rare side effect of checkpoint inhibitor antineoplastic therapy.

Differentiating diffuse undifferentiated small-cell carcinoma of the thyroid from malignant lymphoma is difficult. A case of small-cell carcinoma was studied by electron microscopy and is reported here to illustrate the value of electron microscopy in separating epithelial thyroid tumor from lymphoma. Ultrastructurally, the tumor was composed of cells possessing occasional intercellularjunctional complexes and spaces with microvilli. There were abundant free ribosomes and well-developed rough endoplasmic reticulum in the cytoplasm. Golgi apparatus, smooth endoplasmic reticulum, membrane-bound cytosomes, and centrioles were also evident. Numerous swollen mitochondria were seen in some tumor cells. A few large tumor cells characterized by abundant cytoplasm containing few mitochondria, endoplasmic reticulum and numerous microfibrils were also observed. A few collagen fibers, lymphocytes and plasma cells were present among tumor cells. No basement membranes nor virus-like particles were seen.

Introduction Cribrifrom-morular variant of papillary thyroid carcinoma (CMVPTC) is an uncommon thyroid neoplasm that occurs predominantly in women and is sometime associated with familial adenomatous polyposis (FAP). Some of these tumors may undergo dedifferentiation to poorly differentiated thyroid carcinoma (PDTC). We describe a rare case of this carcinoma in a women without a history of FAP. Case presentation A 49-year-old woman with a history of breast carcinoma presented with a thyroid mass. A CMVPTC was diagnosed after excision. There was no history of FAP. Histological examination showed classical features of CMVPTC in most areas, but about 20% of the carcinoma showed features of a poorly differentiated carcinoma with a solid pattern of growth, increase mitotic activity and a high Ki-67 proliferative index (25%). Immunohistochemical stains were positive for nuclear and cytoplasmic beta catenin staining. These special studies supported the diagnosis. Conclusion CMVPTC with dedifferentiation to PDTC is a rare carcinoma with only 4 previous documented cases in the literature. This aggressive variant of thyroid carcinoma is more common in females, as is CMVPTC, and is often associated with an aggressive biological course. The cases usually express nuclear beta catenin and estrogen, progesterone and androgen receptors have been reported in some cases. Some cases may have somatic alterations of the APC gene and TERT promoter mutations. These carcinomas may metastasize to lung, bones and lymph nodes. Because of its aggressive behavior, patient with this diagnosis should be treated aggressively to control disease spread and mortality from the carcinoma.

resection using ESD knives and post-resection closure with OTSC(Group 1), the other was closure with OTSC and secondary EFTR with snare(Group 2). Results Of 11 patients, 6 cases were in Group 1 and 5 cases in Group 2. The mean time of EFTR procedure was 76.83 ± 34.97 minutes in Group 1 which is significantly longer than that of Group 2 (P=0.0128). The mean time of OSTC closure and length of hospital stay of Group 1 were also longer compared to Group 2, but the difference was not significant. Complete resection (R0) and technical success rate of Group 1 and Group 2 were 83.3% and 100%(P=0.338).VAS scores of Group 1 after operation and 24 hours are significantly higher than those of Group 2(P=0.047 and P=0.009, respectively). In Group 1, One patient had delayed perforation which led to fever and pneumoperitoneum, and one patient developed abdominal pain.No complications associated with endoscopic procedure was observed in Group 2. Conclusions EFTR of pre-resection closure is potentially faster and safer compared with the concept of applying closure after EFTR. Larger prospective controlled studies comparing these two techniques are warranted in the future.

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