Hereditary protein C deficiency (PCD) is caused by mutation in the PC gene (PROC). The homozygous mutation form of PCD is rare. Furthermore, in Asia, cases of noncirrhotic patients with portal vein thrombosis (PVT) secondary to PCD have been rarely reported. The present study reported the case of a patient with PVT due to hereditary PCD. Of note, the mutation of PROCc.152G>A was observed in the patient of the present study. According to the current literature, there has been no previous report regarding the mutation of this gene in China. The patient suffered abdominal pain for 20 days, which was accompanied by vomiting for 2 days. Multiple ulcers and diverticula in the sigmoid colon, as well as erosive small ulcers throughout the colon, were discovered during a colonoscopy. Abdominal angiography indicated thrombosis of the portal vein and its branches. Furthermore, laboratory parameters indicated a hypercoagulable state with normal PC antigen values but decreased PC activity. The discovery of blood coagulation-related genes suggested that homozygous mutation in PC resulted in an amino acid missense mutation. Anticoagulants were prescribed after a diagnosis of type II hereditary PCD with PVT was made. After 15 days, the blood coagulation function of the patient was restored to normal and the symptoms were substantially alleviated. Hence, the present study expanded the mutation spectrum of PROC in China and reaffirmed the value of anticoagulant therapy in PCD.

Background: Systemic lupus erythematosus (SLE) is a systemic disease, which can bring damage to multiple organ systems. It is easily misdiagnosed as mechanical intestinal obstruction and treated by surgery, which not only brings physical pain to patients, but also increases their economic burden. On the other hand, Castleman disease (CD) is also a rare disease that can be easily missed clinically. Consequently, IPO in SLE complicated by CD is extremely rare in clinical practice and easily ignored for clinicians, which may result in delayed diagnosis, and treatment, and even overtreatment.Case Description: An 18-year-old Chinese woman presented with over a month's history of abdominal pain and fever, accompanied by abdominal distension and nausea. The patient was admitted to a local hospital before admission, and imaging test showed intestinal obstruction. After symptomatic treatment, abdominal pain was relieved, but symptoms reappeared about 20 days later. In addition, a red rash on face, light-sensitiveness and alopecia appeared 7 months prior to presentation. Physical examination showed a temperature of 38.9 ℃, facial butterfly erythema, enlarged axillary lymph nodes, lower abdominal tenderness, and diminished bowel sounds. Laboratory examinations showed proteinuria, decreased white blood cell, low C3 and low C4, positive antinuclear antibody (ANA), and positive anti-double-stranded DNA (anti-dsDNA).Abdominal noncontrast computed tomography (CT) showed partial small bowel obstruction. Chest contrastenhanced CT showed multiple enlarged lymph nodes in the bilateral axillary and mediastinal areas. The results of the axillary lymph node biopsy were consistent with the typical histologic features of clear vascular CD. After glucocorticoid and immunosuppression therapy, the patient's immune indexes and proteinuria gradually returned to normal and abdominal pain did not recur during the follow up. Conclusions: In order to avoid misdiagnosis of IPO in SLE and missed diagnosis of SLE complicated by CD, this case emphasizes the importance of medical history combined with appropriate laboratory examination, imaging examination and lymph node biopsy in SLE patients with lymphadenopathy for accurate diagnosis and reasonable treatment. At the same time, this case report aims to improve the diagnostic thinking of clinicians for similar patients.