[A case of primary gastric mantle cell lymphoma].

Endoscopic examination of a 60-year-old man revealed multiple erosions in the gastric antrum. After 6 months, erosions also formed in the duodenal bulb and systemic lymph nodes become enlarged. After 20 months, the gastroduodenal erosions developed into mucosal ulcers, and the systemic lymph node swelling progressed. Histological examination of the neck lymph node showed mantle cell lymphoma (MCL). This result agreed with the results of the gastroduodenal biopsy. This case was diagnosed as recurrent primary gastric MCL in other areas, with systemic lymph node metastasis and bone marrow invasion. Hyper-CVAD (cyclophosphamide, doxorubicin, vincristine, and dexamethasone), high-dose methotrexate and cytarabine in combination with Rituximab and stem cell transplantation was performed. The gastroduodenal lesions and atypical cells in the bone marrow disappeared after 2 cycles of the chemotherapy. Metastatic lymph node swelling regressed after stem cell transplantation. We have had no evidence of recurrence for 50 months. Primary gastric MCL is very rare and cyclin D1 immunohistochemistry and FISH assay were very useful for the diagnosis of MCL.

Mucinous cystic neoplasm in a young male patient.

A 25-year-old Japanese man was admitted to our hospital with a history of recurrent pancreatitis and a pseudocyst of the pancreas. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) revealed an encapsulated multilocular cystic mass 5 cm in diameter in the pancreatic tail. Endoscopic ultrasonography demonstrated a mural nodule, and endoscopic retrograde pancreatography showed a communication of the lesion with the main pancreatic duct. A neoplastic cystic tumor was suspected, and a resection of the body tail of the pancreas was performed. The lesion was a multilocular cyst having a common fibrous capsule and viscous content. Histologically, the cystic lesion was lined with a single layer of columnar cells with low-grade atypia. Ovarian-type stroma (OS) was confirmed, and it showed positive for antiestrogen receptor and antiprogesteron receptor staining. Based on these findings, the lesion was diagnosed as mucinous cystic neoplasm (MCN), an adenoma that shows extraordinarily high prevalence in women. Further study on the pathogenesis of MCN in male patients should be undertaken to elucidate the process of development.