Carcinoma arising from thyroglossal duct remnants.

Thyroglossal duct cysts (TGDCs) are unusual remnants of the thyroid gland that are rarely observed in association with carcinoma. The present study aimed to showcase the clinical characteristics, diagnosis and management of patients with TGDC carcinoma. It was a single-center study conducted from February 2016 to February 2020. The study involved the retrospective analysis of a series of cases with TGDC carcinoma. A total of 10 patients were included in the study, of whom eight (80%) were females. Their age ranged from 25 to 48 years with a mean age of 39.1 years. A total of five cases (50%) underwent only Sistrunk's procedure, four patients (40%) underwent total thyroidectomy along with Sistrunk's procedure and one patient (10%) was treated by Sistrunk operation and lobectomy. In all of the cases (100%), histopathological examination confirmed papillary thyroid carcinoma in TGDCs. In addition, in the thyroid tissue, 2 cases (20%) also had papillary thyroid carcinoma and 3 cases (30%) had papillary thyroid microcarcinoma. Radioiodine was administered in one patient (10%) with suppressive thyroxine. A three-year follow-up with ultrasound revealed no suspicious lesions in any of the cases. Although rare, carcinoma may develop in the thyroglossal cysts. In this situation, both the thyroid gland and different lymph node compartments should be evaluated for malignancy. Surgical intervention is the cornerstone of management.

Granulomatous mastitis masking ductal carcinoma in situ: A case report with literature review.

Granulomatous mastitis (GM) is a rare inflammatory disorder that infrequently occurs with synchronous breast carcinoma. The present study reports the case of a patient who was initially diagnosed with recurrent GM, which eventually proved to be masking an underlying ductal carcinoma in situ (DCIS). A 30-year-old female presented with left breast pain. On clinical examination, there was a large, palpable and painful lump in the left breast, with axillary lymphadenopathy. Initially, the diagnosis was GM and conservative treatment was applied. Surgical resection was decided upon for the condition after it became recurrent, and the histopathological examination revealed extensive DCIS with GM. Later on, the patient underwent a mastectomy with an axillary sentinel lymph node biopsy. The postoperative follow-up was uneventful. In conclusion, tissue diagnosis has a key role in detecting DCIS masked by GM, especially in young females who are not undergoing regular mammogram screening. The present study shows the challenge that the specialists in this field may face when dealing with recurrent GM of the breast, and warns them to search for a second pathology such as the DCIS presented in the current case.

Sarcoid­like granulomatous inflammation in a carotid body paraganglioma: A case report and mini­review of the literature.

Sarcoid-like granulomatous inflammation (SLGI) is defined as the development of non-necrotizing epithelioid granulomas in patients who do not meet the criteria for systemic sarcoidosis. Its occurrence is known to be linked to diverse conditions, including malignancies, infections, the use of certain drugs and inorganic substances. To the best of our knowledge, the available literature to date lacks any description regarding SLGI in a paraganglioma. The present study describes the first case of SLGI in a carotid body paraganglioma (CBP). A 54-year-old female patient presented with anterior neck swelling for 27 years without any other symptoms. An ultrasonography revealed a multinodular goiter with retrosternal extension and a solid lesion on the right side of the neck measuring 40x30x22 mm, which was suggestive of a CBP. The patient underwent a total thyroidectomy, and the right-side cervical mass was resected via another longitudinal incision. A histopathological examination of the thyroid specimen revealed findings of a multinodular goiter. Sections from the right-side cervical mass confirmed the diagnosis of CBP accompanied by multiple, well-formed, small-medium sized, non-necrotizing epithelioid granulomas associated with multinucleated giant cells, indicative of SLGI. Non-necrotizing epithelioid cell granulomas (as with SLGIs), identical to those observed in sarcoidosis, may rarely be observed in patients who do not meet the criteria of systemic sarcoidosis; however, they have been observed in association with various neoplasms. It is thus crucial to distinguish them from actual sarcoidosis, as misdiagnoses may lead to severe consequences. The presence of SLGIs accompanying a paraganglioma is an extremely rare phenomenon. Due to this, it is difficult to conclude if it confers a better prognosis or not.

Management of Idiopathic Granulomatous Mastitis: A Single Institution Experience.

Introduction: There are multiple management modalities for idiopathic granulomatous mastitis, but the treatment of choice is still under debate. This study aims to evaluate the diagnosis and outcomes of different management modalities in patients with idiopathic granulomatous mastitis and to identify the risk factors associated with recurrence. Method: This is a single-group cohort study that included those patients who had idiopathic granulomatous mastitis. Ultrasonography was conducted for all of the cases using LOGIQ E9 with an ML6-15 transducer (5-15 MHz). A core needle biopsy was conducted to take samples from the cases for histopathological examination. The patients were put on steroid therapy. Whenever the cases did not respond to the steroid therapy, treatment with a combination of low-dose steroids and methotrexate was started. In the lack of response to conservative treatments, surgical interventions were started. Results: Sixty-three cases with a confirmed histopathological diagnosis of granulomatous mastitis were included. The mean age of patients was 35.7 years. The history of more than one childbirth was positive in a large portion of the cases (82.5%). The lesion side was unilateral in 58.7% of the cases. A large proportion of the lesions were classified as BIRADS category 2. The best treatment outcome was yielded by a combination of low-dose steroids and incision and drainage. The factors of age, lesion area (cm2), skin thickening, and white blood cell count enhanced the chance of recurrence. Conclusion: Incision and drainage in combination with a low dose of steroids can give an acceptable outcome with a low rate of recurrence.

Coexistence of acute pancreatitis and an obstructing upper ureteral calculus: does a calculus cause pancreatitis? a case report.

Acute pancreatitis is an inflammatory disease that can affect both the peripancreatic tissues and distant organs. There are few reports of acute pancreatitis caused by endourological procedures. However, an obstructing ureteral calculus causing acute pancreatitis is very rare. Case presentation: A 36-year-old male patient presented with epigastric, and right loin pain with decreased urine output for 3 days. On physical examination, he had central abdominal and right flank tenderness. An abdominal ultrasound showed mild to moderate ascites, a hyperechoic pancreas, a small (26×77 mm) left kidney with increased echogenicity, right renal hypertrophy with moderate hydronephrosis, and a dilated upper ureter due to a 10 mm obstructing stone with a perirenal fluid collection. The diagnosis of acute pancreatitis with an obstructing right upper ureteric stone was established. Under spinal anesthesia, an emergency ureteroscopy with laser fragmentation of the stone was performed, and a JJ stent was inserted. He developed postobstructive diuresis and his renal function was improved with a rapid decline of pancreatic enzymes as well. Clinical discussion: Two theories explain the presentation of acute pancreatitis by ureteral obstruction. First, the obstructed severe hydronephrotic kidney compresses the duodenum and head of the pancreas, obstructing the distal part of the common bile duct and triggering the elevation of pancreatic duct pressure, bile reflux, trypsin activation, and pancreatic autodigestion. The second theory states that acute pancreatitis develops when urine is extravasated from an obstructed kidney into the adjacent tissues, irritating the uncinate process of the pancreas. Conclusion: Although mentioning ureteral obstruction as a cause of pancreatitis is scarce, the clinician should be aware that in each case of ureteral obstruction, the emergence of acute pancreatitis is a possible complication.

Thyroglossal duct diseases: presentation and outcomes.

OBJECTIVE: The incidence of thyroglossal duct diseases in the general population is about 7%. We aimed to demonstrate the clinical presentations and management of thyroglossal duct diseases. METHODS: We conducted a retrospective review of all patients who underwent surgery for histopathologically confirmed thyroglossal duct cyst, sinus, or fistula at a single center. RESULTS: A total of 151 cases were included in this study. There were more female patients (87, 58%) than male patients (64, 42%). The patients' ages ranged from 1 to 63 years old. The most prevalent complaint was painless upper midline neck swelling (93.3%). Most cases were diagnosed as thyroglossal duct cysts (137, 90.7%). Six cases (4%) were associated with carcinoma. All the cases were managed using the modified Sistrunk procedure. There were no procedure-related complications, and five cases of recurrence. CONCLUSIONS: Although thyroglossal duct cyst is the most common neck anomaly in children, it may also present with various characteristics later in life. This condition can be managed successfully without complications and with a low recurrence rate.

Non-operative management of umbilical pilonidal sinus: One more step towards ideal therapy.

There are controversies regarding the management of umbilical pilonidal sinuses. The current study aims to report on the efficacy of a non-operative, umbilical conserving procedure in the treatment of umbilical pilonidal sinus. This is a prospective, single cohort study. The cases were managed in a single private practice center. Patients were assessed and managed throughout the previous nine years (from January 2013 to June 2022). The required information was obtained from the center's medical database. The current study included 114 patients. There were 82 (71.9%) male patients. The patients' ages varied from 14 to 56 years (mean = 23.24). The umbilicus was retracted under local anesthesia. The sinuses were cleaned with povidone-iodine. Following the drying of the cavity, the mixture was put in the umbilicus, and the area was dressed. The amount of mixture was determined by the size of the cavity. Following treatment, the patients were directly discharged home with instructions to remove all hair from the chest and abdomen and keep the dressing dry for three days. After three days, the patients were advised to use a clean cotton swab to remove the injected mixture. Recurrence was reported in 5 cases (4.4%). The current technique might be used effectively in the treatment of umbilical pilonidal sinus. It is an umbilical preserving technique with a minimal recurrence rate.

Pattern of facial nerve palsy during parotidectomy: a single-center experience.

OBJECTIVE: This study was performed to report and analyze the prevalence of permanent facial nerve paralysis following parotidectomy for various benign and malignant lesions in a single center. METHODS: This single-center retrospective study included all patients who underwent parotidectomy (total and superficial) for benign and malignant tumors and chronic inflammatory diseases during a 6-year period. Patients who had previously undergone an operation of the parotid gland and those with preoperative facial weakness were excluded. RESULTS: The study included 127 patients ranging in age from 14 to 83 years (median, 45.89 years). Most patients were female (n = 83, 65.4%). The most prevalent procedure was superficial parotidectomy (n = 117, 92.1%), followed by total parotidectomy (n = 6, 4.7%). The average operative duration was 138 minutes (range, 80-400 minutes). Histopathology revealed that 109 (85.8%) patients had benign tumors, 14 (11.0%) had malignant tumors, and 4 (3.1%) had chronic sialadenitis. Only two patients sustained an injury to the cervical branch of the facial nerve. CONCLUSION: In this single-center experience of parotid surgery, the rates of transient and permanent facial paralysis were acceptably low at 9.0% and 1.6%, respectively, for all pathologies.

Thymoma with osseous metaplasia; a case report with a brief literature review.

INTRODUCTION AND IMPORTANCE: The thymus is a primary lymphatic organ within the mediastinum that plays an essential role in developing and maintaining cell-mediated immunity. The current study aims to report a case of intra-tumoral osseous metaplasia of the thymus gland, which is an infrequent phenomenon. CASE PRESENTATION: A 43-year-old male presented with weakness and easy fatigability for 2 months. The patient had an elevated anti-acetylcholinesterase antibody (19.5 nmole/L). Magnetic resonance imaging showed a round, capsulated, enhanced mass in the anterior mediastinum measuring 5.5 × 3.5 cm, suspecting thymoma. The patient underwent plasmapheresis three times in one week, under general anesthesia, in a supine position, sternotomy was performed, and the thymoma was totally resected. DISCUSSION: Thymomas are known to occur in all age groups with the peak of nearly between 35 and 70 years with the median age of 54 years. The sex distribution of thymoma is approximately equal with slight predilection of women in old age groups. However, among all reported cases of thymomas with osseous metaplasia, the majorities are female. The significance of this ossification is still to be clarified. CONCLUSION: Although it is rare, secondary changes in thymoma may occur including calcification and ossification.

Breast cancer metastasizing to the contralateral axilla several years after treatment: A case report with literature review.

INTRODUCTION AND IMPORTANCE: Lymph node metastasis is the most prominent prognostic factor in breast cancer. The aim of this paper is to report a case of contralateral axillary lymph node metastasis (CAM) which look like metachronous initially, but histopathologicaly confirmed as synchronous CAM. CASE PRESENTATION: A-44-year old female was a known case of left breast cancer five years prior to this presentation (T2,N2,M0, grade III, Triple negative, multifocal invasive ductal carcinoma). On follow up, multiple contralateral axillary suspicious lymph nodes were discovered. Fine Needle Aspiration Cytology from the lesion revealed grade III, Triple negative, invasive ductal carcinoma consistent with metastasis from the left invasive ductal carcinoma. Bilateral mastectomy and right axillary dissection were performed. The histopathological examination and immunohistochemistry showed left breast recurrent 0.5 cm grade III, Triple negative invasive ductal carcinoma. DISCUSSION: If a cancer is found in the contralateral axilla, three main potential sources should be considered: contralateral spread from the original breast tumor, metastasis from an occult primary in the ipsilateral breast, and metastasis from an extramammary site. CONCLUSION: Although CAM in patients with breast cancer is an uncommon condition, it is still possible to occur. There is a controversy regarding the appropriate management.

Prediction of outpatient visits and expenditure under the Universal Coverage Scheme in Bangkok using subscriber's attributes: A random forest analysis.

Objectives: There is limited evidence on methods to allocate budgets to healthcare providers under capitation schemes. The objective of this study was to construct and test models that predict outpatient visits and expenditure for each healthcare facility using subscriber data from the preceding year. Study design: We used the database of the Universal Coverage Scheme in Bangkok, Thailand that stores subscriber information and healthcare service utilization data. One-percent and ten-percent random samples of subscribers were selected as training and testing groups, respectively. Methods: Using data of the training group, we constructed a model using a random forest algorithm to predict outpatient visits and expenditure in 2017 from the 2016 data. The model was applied to the testing group and facility-level predicted number of visits and expenditure were compared with actual data. Results: The identically-structured training and testing groups consisted of 37,259 and 371,650 subscribers, respectively. Approximately 25% of subscribers utilized outpatient services. The R2 for models predicting facility-level utilization rate (visits/subscribers) and expenditure per subscriber in 2017 were 0.85 and 0.75, respectively. Conclusions: The model to predict outpatient visits and expenditure performed well. Such a prediction model may be useful for allocating budgets to healthcare facilities under capitation systems.

Hydatid cyst of thyroid gland, a rare case report with a literature review.

INTRODUCTION: Although hydatid cysts can affect any organ in the body, reports regarding affection of thyroid gland are scanty in the literature. This report aims to present a case of thyroid hydatid disease with literature review. CASE REPORT: A 48-year-old female presented with painless anterior neck mass of about 2 year duration. There was an ill-defined, central anterior neck mass, with a smooth surface and mobile with deglutition. Ultrasound of the thyroid gland revealed an enlarged left lobe of thyroid gland due to well defined thick wall cystic nodule. The patient underwent left thyroid lobectomy under general anesthesia, the pathology report revealed hydatid cyst of thyroid gland. DISCUSSION: Liver and lungs are often the end destination for hydatid cysts, while other places like mediastinum, diaphragm, cardiac, smooth and skeletal muscles, abdominal and chest walls are rarely involved. In this case, the cyst affected even a rarer organ which was the left lobe of thyroid gland. Most of the time the disease is asymptomatic and is found accidentally, yet depending on the site and size of the cysts, symptoms can occur. CONCLUSION: Hydatid disease of thyroid gland is an extremely rare condition. The main presenting symptom is swelling. Operation under general anesthesia is the only modality of treatment.

Double cystic duct, a review of literature with report of a new case.

INTRODUCTION: Although cystic duct variation is quite common, duplication of cystic duct is an extreme rare variant. We report a case of double cystic duct with literature review. A 33-year old female presented with right upper quadrant pain of three day duration, associated with nausea and poor appetite. The patient reported previous three attacks of right upper quadrant pain within the last two years. On examination: Murphy's sign was positive and the right upper quadrant was tender. Abdominal ultrasound showed multiple gall stones. Oesophago-gastro- duodenoscopy was normal. Under general anesthesia, four port formal laparoscopy was done, double cystic duct was found. Histopathological examination showed features of chronic cholecystitis. CONCLUSION: double cystic duct is a very rare variant of the cystic duct anomaly. Identification pre or intraoperatively is very important to prevent ductal injury.

Porocarcinoma; presentation and management, a meta-analysis of 453 cases.

BACKGROUND: porocarcinoma is a rare sort of skin cancer developing from sweat glands. Its clinical course and management are not well understood. OBJECTIVES: the current meta-analysis is to address the presentation and management of porocarcinoma. DATA SOURCES: Web of Science, PubMed, MEDLINE on OVID and Google scholar were searched for English-language studies published before December 1, 2016. RESULTS: The review of literature revealed 453 cases. From which 222 (49%) cases were male and female were 231 (51%). The mean age was 67.57 years. The mean duration of presentation was 5.57 years ranging from 4 days to 60 years of age. The most common site of affection is the head and neck (39.9%) followed by lower extremity (33.9%). Mass and nodule are the most common modes of presentation. Metastasis occurred at presentation in 110 (31%) cases. The most common organ to which porocarcinoma metastizes is the nearby lymph node (57.7%). CONCLUSIONS: Porocarcinoma is an aggressive skin cancer. Surgery is the main modality of treatment. SYSTEMATIC REVIEW REGISTRATION NUMBER: reviewregistry233.

Metaplastic breast carcinoma with osseous differentiation: A rare case report.

INTRODUCTION: Metaplastic breast carcinoma (MBC) is a rare type of breast cancer. Osseous differentiation is a very rare subtype. Reporting this kind of case is important because its clinical course and line of management are poorly mentioned in the literatures. We present a very rare case of MBC with osseous differentiation. A 48-year-old female presented with painless hard mass of the left breast. Examination and investigations showed MBC with osseous differentiation. She was managed by operation with adjuvant chemotherapy. CONCLUSION: MBC with osseous differentiation is a very rare type of breast carcinoma presenting with hard mass and managed by mastectomy, axillary lymph node sampling and adjuvant chemotherapy.

Hibernoma subescapular. Presentación de un caso y revisión de la bibliografía / Subscapular hibernoma: a case report and literature review

Los hibernomas son tumores raros compuestos de grasa parda. La mayor base de datos encontrada contiene 170 casos. En humanos surge a partir de vestigios de la grasa parda fetal. La escisión incompleta puede tener como resultado el continuo crecimiento y recurrencia, incluso en tumores en apariencia benignos. Este caso fue un hallazgo quirúrgico que se detectó tras realizar la linfadenectomía axilar en un carcinoma de la mama derecha (AU)

Hibernomas are uncommon neoplasms composed of brown adipose tissue. The largest database found contains 170 cases. In humans, this type of tumor arises from the remnants of fetal brown adipose tissue. Incomplete excision may result in continued growth and recurrence, even in tumors appearing to be histologically benign. The interest of the case reported herein lies in detection of the tumor during axillary lymphadenectomy for a right breast carcinoma (AU)

Multiple sclerosis in Jordan and Iraq. Clinical and social overview.

OBJECTIVES: To verify clinical features of multiple sclerosis (MS) patients throughout the course of their illness and to study the socioeconomic status of MS patients in Jordan and Iraq. METHODS: Fifty-two patients were examined by 2 neurologists looking for the clinical and radiological features of MS at Al-Bashir Teaching Hospital, Amman, Jordan (35 patients), and Rezgary Teaching Hospital-Erbil, Kurdistan, Iraq (17 patients) from January 2004 to July 2007. The study design was based on full clinical examination of MS patients, investigate the signs, and symptoms, tabulating them, and show the percentage of their presence in all patients, and then comparing the results with other findings through systematic review of the available data from other reviews. RESULTS: The percentage of different symptoms, signs, and radiological features of the 52 MS patients were recorded. Weakness in one limb, mostly the leg (90.4%) was the most common symptom described by our patients, while hyperreflexia was the most prominent sign in MS patients (75%). Higher level of school performance, and moderate to good socioeconomic status were the common status between MS patients. The MRI results were interpreted according to the anatomical sites, and according to different MRI sequences, and the MRI showed MS plaques in almost all patients. CONCLUSION: This study showed comparable findings with other studies, except nystagmus, which was less observed in Jordanian and Iraqi patients.

Diagnóstico y tratamiento de las lesiones benignas de la mama en el embarazo / Diagnosis and treatment of benign breast lesions during pregnancy

Objetivo. Estudiar retrospectivamente el diagnóstico y tratamiento de la patología benigna de la mama durante el embarazo y puerperio realizado en nuestra Unidad. Revisamos la literatura existente al respecto.Materiales y métodos. De enero de 2001 a marzo de 2005 diagnosticamos un total de 91 mujeres (gestantes o puérperas) con patología mamaria benigna manifestada como nódulo palpable o clínica inflamatoria, con un rango de edad de 23-36. En todos los casos se realizóecografía y citología diagnóstica, siendo necesaria la realización de biopsia percutánea con aguja gruesa en tres ocasiones. En el caso de los abscesos se procedió también a su drenaje. Todo se realizó tras la obtención del correspondiente consentimiento informado.Resultados. En 28 casos (30%) se detectaron tumoraciones: fibroadenomas (12), adenomas de lactancia (9), galactoceles (5) y papilomas (2). El tratamiento fue conservador con seguimiento ecográfico, salvo en un caso que precisó tratamiento quirúrgico en el tercer trimestre. En 63 ocasiones (70%) la patología fue inflamatoria, evidenciándose abscesos en 24 (38%), de los cuales se drenaron con aguja fina 16 y concatéter pig-tail 3, según protocolo, atendiendo a su tamaño (menor o mayor de 3 cm). En 5 casos se realizó drenaje quirúrgico.Conclusiones. La patología benigna más frecuente durante la gestación es la inflamatoria, que se maneja satisfactoriamente con antibióticos y drenaje percutáneo, siendo el resultado estético mejor. La ecografía es la técnica diagnóstica de elección junto con la citología y sólo en casos dudosos realizaremos biopsia percutánea por el riesgo de fístulas

Objectives. To retrospectively study the diagnosis and treatment of benign breast disease during pregnancy and breastfeeding at our department. To review the relevant literature.Materials and methods. From January 2001 to March 2005, a total of 91 pregnant or breastfeeding women (age range: 23-36 years) were diagnosed with benign breast pathology. All patients presented with palpable nodules or inflammatory symptoms. Ultrasound-guided fineneedle cytology was performed in all cases and percutaneous core biopsy was considered necessary in three cases. Abscesses were drained when present. Patients provided their informed consent before all procedures.Results. Tumors were detected in 28 cases (30%): fibroadenomas (n = 12), lactating adenomas (n = 9), galactoceles (n = 5), and papillomas (n = 2). Conservative treatment with ultrasound follow-up was employed in all cases except one, which required surgical treatment in the third trimester. On 63 occasions (70%), the pathology was inflammatory, including abscesses in 24 cases (38%); abscesses were drained using fine-needle aspiration (n = 16) or pig-tail catheter (n = 3), according to protocol, depending on the size of the abscess (less than or greater than 3 cm). In 5 cases the abscesses were drained surgically.Conclusions. The most common benign breast pathology during pregnancy is inflammatory and is satisfactorily managed with antibiotics and percutaneous drainage with good esthetic results. Ultrasound is the diagnostic technique of choice, together with cytology; percutaneous biopsy is only performed in uncertain cases to minimize the risk of fistulas. Management of tumors after histological confirmation should be conservative with close follow-up. These tumors cause no problems for the child, the mother, or breastfeeding

[Diagnosis and treatment of benign breast lesions during pregnancy]. / Diagnóstico y tratamiento de las lesiones benignas de la mama en el embarazo.

OBJECTIVES: To retrospectively study the diagnosis and treatment of benign breast disease during pregnancy and breastfeeding at our department. To review the relevant literature. MATERIALS AND METHODS: From January 2001 to March 2005, a total of 91 pregnant or breastfeeding women (age range: 23-36 years) were diagnosed with benign breast pathology. All patients presented with palpable nodules or inflammatory symptoms. Ultrasound-guided fine-needle cytology was performed in all cases and percutaneous core biopsy was considered necessary in three cases. Abscesses were drained when present. Patients provided their informed consent before all procedures. RESULTS: Tumors were detected in 28 cases (30%): fibroadenomas (n = 12), lactating adenomas (n = 9), galactoceles (n = 5), and papillomas (n = 2). Conservative treatment with ultrasound follow-up was employed in all cases except one, which required surgical treatment in the third trimester. On 63 occasions (70%), the pathology was inflammatory, including abscesses in 24 cases (38%); abscesses were drained using fine-needle aspiration (n = 16) or pig-tail catheter (n = 3), according to protocol, depending on the size of the abscess (less than or greater than 3 cm). In 5 cases the abscesses were drained surgically. CONCLUSIONS: The most common benign breast pathology during pregnancy is inflammatory and is satisfactorily managed with antibiotics and percutaneous drainage with good esthetic results. Ultrasound is the diagnostic technique of choice, together with cytology; percutaneous biopsy is only performed in uncertain cases to minimize the risk of fistulas. Management of tumors after histological confirmation should be conservative with close follow-up. These tumors cause no problems for the child, the mother, or breastfeeding.

Differential activation in the medial temporal lobe during a sound-sequence discrimination task across age in human subjects.

To elucidate the brain mechanisms to encode sequential events, event-related potentials (ERPs) were recorded during a sound-sequence discrimination task using young and middle-aged adult subjects. In the task, a series of six or 12 kinds of natural sounds were sequentially presented; 70-80% of the stimuli were presented in a fixed order (Non-target), but the remaining stimuli, in a random order (Target). The subjects were instructed to detect the Targets and press a button at the end of each Target. In a control task, the same sounds were randomly presented (Control), and they were instructed to press the button at the end of each sound. Behavioral results indicated that the young subjects learned the task faster than did the middle-aged subjects. Positive ERP waves were evoked by Targets and Non-targets in the parieto-occipital area around 300-700 ms after stimulus onset. The mean amplitudes during this period in the young subjects were larger in Target than Control conditions, and those in Target condition were larger in the young than middle-aged subjects. Furthermore, the mean amplitudes in the Target condition were significantly correlated with behavioral performance. Equivalent dipoles for the ERPs evoked by Targets were estimated in the medial temporal lobe including the hippocampal formation and parahippocampal gyrus. The results suggest that the ERPs around 300-700 ms latency are involved in sound-sequence information processing. Furthermore, decrease in amplitudes of this positivity in the middle-aged subjects suggests that age-related memory decline is associated with deficits in encoding and retrieval of unfamiliar sequence.