Stem cells are defined as having both self-renewal and multilineage differentiation capacity. Based on this definition, the existence of mesenchymal stem cells （MSCs） in bone marrow （BM） has been well documented. However, the in vivo dynamics of MSCs in intact BM conditions remain unclear because most experiments have used in vitro culture systems or transplantation assays. Recent studies using genetic mouse models revealed that perivascular stromal cells function as BM-MSCs. Furthermore, mouse genetic approaches made it possible to perform lineage tracing analyses of BM-MSCs in vivo to investigate the underlying mechanisms that regulate cell fate. Here, we reviewed recent information about identification and differentiation mechanisms of BM-MSCs in vivo.
Perioperative oral management is recognized as an important supportive therapy in cancer treatment and is being implemented in many medical institutions. The Estimation of Physiologic Ability and Surgical Stress scoring system （E-PASS） can grasp the risk of postoperative complications from the physiological functions of patients and the degree of surgical invasion, and has been reported to be useful in the field of gastroenterological surgery.
E-PASS consists of preoperative risk score （PRS） representing the physiological functions of the patient, surgical stress score （SSS） representing the magnitude of the operation, and comprehensive risk score （CRS） defined from both PRS and SSS. Based on the value of CRS, patients who underwent gastric cancer surgery were divided into those who received perioperative oral management （oral management group, n＝99） and patients who did not receive perioperative oral management （control group, n＝165）, and the incidence of postoperative complications of the two groups was compared and examined.
In the patient group with CRS of 0.2 or more, the oral management group showed a significant decrease in the postoperative complication rate compared with the control group.
By identifying the patients who need perioperative oral management based on the value of CRS, it is considered beneficial for patients and enables limited medical and human resources to be effectively utilized. We could predict the onset of postoperative complications by grasping age and surgical invasion in advance without being limited only to the disease. It could be a useful index that focuses on perioperative oral management.
A 57-year-old male was referred to our department with a chief complaint of a right submandibular mass. Fluorodeoxyglucose-positron emission tomography/computed tomography revealed a lesion with abnormal FDG uptake （SUV max. 9.1） in the right submandibular region. Malignant lymphoma, cervical lymph node metastasis from an unknown primary cancer, and tuberculous lymphadenitis were suspected. Excisional biopsy of the submandibular mass was performed, and the histopathological diagnosis was epithelioid cell granuloma with necrotic tissue. Under the suspicion of tuberculosis, Ziehl–Neelsen staining was added to identify the acid-fast bacteria. Moreover, testing with sputum acid-fast bacteria staining, tuberculin reaction test, and interferon-gamma release assay were performed. The result of Ziehl–Neelsen staining was negative, and no acid-fast bacteria were detected from the sputum. However, the results of the tuberculin reaction test and interferon-gamma release assay were positive. Based on these results, a diagnosis of tuberculous cervical lymphadenitis was made. Therefore, quadruple chemotherapy including isoniazid, rifampicin, pyrazinamide, and ethambutol was started. After one year and two months from the start of the treatment, the course of the patient was uneventful without a new lesion or relapse.
Syncopal attacks associated with carotid sinus syndrome （CSS） are rare in cases of head and neck malignancy. Here, we report a case of CSS with syncopal attacks in a patient with recurrent neck metastasis from oral cancer. A 46-year-old man presented with a painful mass of the tongue. Upon clinical diagnosis of oral cancer of the tongue （T4aN2bM0）, radical neck dissection, supraomohyoid neck dissection, subtotal glossectomy, and reconstruction using free rectus abdominis myocutaneous flap were performed. Pathological findings of tissue samples from the neck dissection revealed multiple positive lymph nodes; therefore, chemoradiotherapy （CDDP, 5FU＋RTx 60Gy） was administered. Three months after the chemoradiotherapy, frequent syncope attacks occurred with low blood pressure and bradycardia. Computed tomography showed a 36mm irregular mass with infiltration at the bifurcation of the carotid artery. A diagnosis of recurrent neck metastasis from oral cancer with CSS was made and weekly chemotherapy with cetuximab and paclitaxel was administered 24 times. The treatment induced a partial response and the syncopal attacks ceased. The patient was discharged from hospital and with continuous outpatient chemotherapy showed improved levels of activities of daily living. Chemotherapy for unresectable recurrent neck metastasis is suggested to be an effective treatment in cases of CSS with syncopal attacks.
Acinic cell carcinoma is a rare tumor of salivary gland origin. Acinic cell carcinoma usually occurs in the parotid gland, and is most frequently seen in adults. We report a rare case of acinic cell carcinoma in the submandibular gland of a 13-year-old boy. He was referred to our department because of painless swelling in the right submandibular gland. US revealed a mass like a pleomorphic adenoma, but it had an unclear margin between the salivary gland tissue and mass lesion. CT and MRI showed that the mass included enhanced or non-enhanced areas with unclear margin. We diagnosed this lesion as a salivary gland tumor, and excised the whole submandibular gland because the tumor was surrounded by normal salivary gland tissue and did not invade adjacent structures. Histological findings of the surgical specimen revealed that this tumor was acinic cell carcinoma and was localized within the submandibular gland with normal capsule. Nine years after operation, there has been no evidence of recurrence or metastasis.
The risk of systemic infection increases in situations where immunosuppressive agents and corticosteroids are administered and also in cases where highly invasive surgery has been performed. Virus infections that develop in these types of situations are often fatal. We investigated the usefulness of a cytological examination in four cases of viral stomatitis to verify the diagnosis. All of the four cases had immuno-compromised hosts, and severe ulcers on the oral mucosa were present. Scraping cytology was carried out on the surface of the ulcer. Ground glass-like nuclei in the sampled cells were found; thus, a virus infection was strongly suspected. It was concluded that cytological examination is a very useful method to support the diagnosis of virus infections in immuno-compromised hosts as cytology is a relatively uninvasive procedure compared to a biopsy procedure.
Malignant tumors occur during pregnancy in about 1 in 1,000-1,500 cases and reports of oral and maxillofacial cases are rare. Here, we report a case of tongue cancer that occurred during pregnancy. The patient was a 35-year-old woman with a chief complaint of pain in the tongue. She was 9 weeks pregnant and her general condition was good. The oral examination revealed a 15mm elastic hard mass with erosion and a 20mm white lesion. The clinical diagnosis was tongue squamous cell carcinoma （T2N0M0）. Partial glossectomy was performed under general anesthesia at 11 weeks. Delayed neck metastasis appeared in the submandibular lymph node 5 months post-surgery. Modified radical neck dissection was performed at 34 weeks of pregnancy with monitoring via a nonstress test by an obstetrician-gynecologist. The pathological diagnosis of the lymph nodes was pN2b with extracapsular metastasis. She delivered a healthy baby girl weighing 2,805g by Caesarean section. Chemoradiotherapy with 59.4Gy of radiotherapy and cetuximab was additionally performed 9 weeks post-surgery. Two years after treatment, she remains healthy with no recurrence or metastasis.