We present a case of rare primary yolk sac tumour of the urinary bladder in adulthood. A 31-year-old female patient presented with a history of chronic ketamine abuse, which has not previously been shown to be associated with malignancy development. The final diagnosis was established only after radical cystectomy. A computed tomography (CT) scan showed paraaortic lymph node metastasis. The patient was treated with systemic chemotherapy. A review of the literature revealed that surgical excision and cisplatin-based chemotherapy remain to be the standard of care for extragonadal yolk sac tumours.

Hyperparathyroidism-jaw tumor syndrome (HPT-JT) is an autosomal dominant disease characterized by the occurrences of parathyroid tumors and ossifying fibroma of maxilla/mandible. It is caused by mutations in CDC73 gene and mutation carriers are at increased risk of parathyroid carcinoma. Hyperparathyroidism could be the sole manifestation. We reported two Chinese patients having parathyroid neoplasm with equivocal malignant potential and parathyroid carcinoma respectively with both germline and somatic CDC73 mutations detected. Both of them presented with severe hypercalcemia and primary hyperparathyroidism with no other HPT-JT associated tumors and negative family history. We identified one novel germline mutation CDC73 NM_024529.4: c.1475G > A; NP_078805.3: p.Trp492X and one novel somatic mutation CDC73 NM_024529.4: c.142G > T; NP_078805.3: p.Glu48X. The other germline mutation CDC73 NM_024529.4: c.226C > T; NP_078805.3: p.Arg76X and somatic mutation CDC73 NM_024529.4: c.85delG; NP_078805.3: p.Glu29SerfsX8 were previously reported. This is the first report of CDC73 mutations in the Chinese population. Genetic analysis is reliable to confirm the underlying hereditary basis of hyperparathyroidism. By identification of mutations, the patient and the family members could benefit from regular surveillance for early detection of tumors.

Protein-losing enteropathy (PLE) is a rare syndrome of gastrointestinal protein loss that may complicate a variety of diseases. The primary causes can be divided into erosive gastrointestinal disorders, nonerosive gastrointestinal disorders, and disorders involving increased central venous pressure or mesenteric lymphatic obstruction.Herein, we report on a 65-year-old man with PLE caused by invasive gastrointestinal stromal tumor (GIST). To our best knowledge, this is the first reported association between GIST and PLE. A brief review of the literature on the incidence, pathogenesis and management of GIST is also presented.