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Hiroyuki Kobayashi

Publications and source records attributed to Hiroyuki Kobayashi.

At least 73 records · Page 4Linked to original sources
PubMed2005

Botryoid Wilms' tumor: a report of two cases.

We report two rare cases of botryoid Wilms' tumor (BWT) occupying the renal collecting system with no macroscopic parenchymal mass. In case 1, a 3-year-old boy presented with a mass in the right flank, low-grade fever, abdominal pain, and macrohematuria. Radiology revealed an enlarged right kidney with a heterogeneous mass occupying a large part of the dilated renal calyx, pelvis, and ureter. Radical right nephroureterectomy was performed. The histopathologic diagnosis was nephroblastoma, and the pedicle of the tumor was attached to the renal parenchyma near the pelvic wall. In case 2, a 2-year-old boy presented with macrohematuria, and the clinical course was almost the same as in case 1. No local recurrence or metastatic spread has been detected for 4 years postoperatively in case 1 and for 9 months postoperatively in case 2.

Child, Preschool↗
PubMed2005

Posterior urethral diverticulum after laparoscopic-assisted repair of high-type anorectal malformation in a male patient: surgical treatment and prevention.

Currently, laparoscopic-assisted colon pull-through (LACPT) is the treatment of choice for male patients with high-type imperforate anus and rectourethral fistula. Since laparoscopy was introduced for treating this condition, reports concerning post-LACPT complications are rare. Here we discuss the case of a boy, now 3.5 years old, born at 37 weeks' gestation weighing 2,300 g, who was diagnosed with rectobulbar urethral fistula (RUF) at birth. LACPT was performed when the boy was 11 months old and weighed 7.2 kg. No intraoperative complications occurred, and the initial post-LACPT course was uneventful. When he was 2 years old, he developed dysuria requiring urethral catheterization. Diagnostic radiology confirmed a large cystic mass behind the bladder, suggestive of a posterior urethral diverticulum (PUD). Histopathology of the excised mucosa of the cyst showed colonic mucosa, confirming that the cyst was indeed an enlarged residual RUF. We discuss our treatment and our approach to prevention.

Anus, Imperforate↗
PubMed2005

Cholecystectomy alone is inadequate for treating forme fruste choledochal cyst: evidence from a rare but important case report.

Treatment of "forme fruste" choledochal cyst (FFCC) where pancreaticobiliary malunion (PBMU) is associated with minimal dilatation of the common bile duct (CBD) remains controversial. PBMU allows pancreaticobiliary reflux to occur, which causes complications such as recurrent pancreatitis and gallbladder cancer. Therefore, some surgeons opt to treat FFCC by cholecystectomy alone in order to prevent gallbladder cancer, with the result that pancreaticobiliary reflux could still occur. Our treatment of choice-excision of both the CBD and the gallbladder, followed by Roux-en-Y hepatico-jejunostomy-can eliminate pancreaticobiliary reflux and prevent complications. Our case, a 2-year-old boy, initially presented to a hospital abroad with recurrent abdominal pain. Endoscopic retrograde cholangiopancreatography showed massive protein plugs impacted in the papilla of Vater and mild CBD dilatation, but PBMU was not identified. Intraoperative cholangiography performed during laparotomy 5 days later suggested PBMU with minimal CBD dilatation. Despite these findings, cholecystectomy with T-tube drainage was performed rather than CBD excision with biliary reconstruction. Postoperative T-tube cholangiography clearly showed PBMU. The T-tube was removed after 2 weeks, and 3 months later the boy was referred to us because of recurrent pancreatitis. We performed CBD excision and Roux-en-Y hepatico-jejunostomy. His postoperative course was uneventful, and he is well after 10 years of follow-up. This case provides strong evidence that CBD excision with biliary reconstruction is mandatory for treating FFCC and, conversely, that cholecystectomy alone is inadequate for treating children with FFCC.

Anastomosis, Roux-en-Y↗
PubMed2005

Median sternotomy provides excellent exposure for excising anterior mediastinal tumors in children.

Median sternotomy (M-S) provides excellent exposure and allows dissection of the medial side of an anterior mediastinal tumor (AMT) with minimal risk. We report our experience of resecting AMT using M-S. Five children with AMT were treated using M-S between 1997 and 2004 at our institute. Ages at M-S ranged from 8 months (case 2) to 9 years (case 1) and AMT ranged in size from 5x6x7 cm3 (case 2) to large enough to occupy nearly the entire right thoracic cavity (cases 4 and 5). AMT were resected completely in all cases through M-S with the patient in the supine position. M-S alone was used in cases 1, 2, and 3, and cases 4 and 5 required additional incisions. There were dense adhesions between AMT and important mediastinal structures such as the anterior part of the pericardium (cases 1 and 2), left phrenic nerve (case 3), and pulmonary vessels (case 4, 5), but all were dissected safely under direct vision. There was no respiratory or cardiovascular compromise during M-S due to compression of the healthy lung and mediastinum. Histopathologic findings were mature teratoma in cases 1, 3, and 5, immature teratoma in case 2, and pleuropulmonary blastoma in case 4. Postoperative recovery was unremarkable. After mean follow-up of 3.4 years, cases 1, 2, 3, and 5 are currently well with no signs of recurrence, but case 4 died from disseminated intravascular coagulation during postoperative chemotherapy for massive local tumor recurrence 6 months after surgery. Based on our experience, M-S allows access to all aspects of AMT under direct vision, and provides excellent exposure, thus facilitating complete resection.

Child↗
PubMed2005

Prospective analysis of primary modified Georgeson's laparoscopy-assisted endorectal pull-through for Hirschsprung's disease: short- to mid-term results.

The aim of this study was to analyze the short- to mid-term outcome of primary modified Georgeson's laparoscopy-assisted endorectal pull-through (PMGLEPT) for Hirschsprung's disease (HD). HD patients treated by PMGLEPT were evaluated prospectively by a single surgeon using a standard structured questionnaire to assess complications, incidence of enterocolitis, and evaluate continence (CE). CE involved scoring five parameters (frequency of motions, severity of staining/soiling, severity of perianal erosions, anal shape, and requirement for medications) on a 3-point scale (0, 1, and 2 for each parameter). Thus, scores for CE were: 10 = normal, 8-9 = good, 6-7 = fair, and 0-5 = poor. Our modifications include transanal rectal dissection starting below or on the dentate line, near total excision of the posterior rectal cuff, and intraoperative acetylcholinesterase staining to accurately identify normal colon. Patients with total colon aganglionosis or trisomy-21 were excluded, leaving 33 cases of PMGLEPT performed between 1997 and 2004. Mean operative age was 11.0 months. Follow-up ranged from 8 months to 7 years (mean 4.0 years). There were no intraoperative complications. Post-PMGLEP, bowel obstruction occurred in 1 subject who required middle colic division for pull-through (PT), and enterocolitis occurred in 3 (9.1%) of 33 patients. In 20 subjects aged over 3 years with a follow-up period of more than 12 months, final CE was normal in 5, good in 10, fair in 4, and poor in 1, despite staining/soiling being present in 12 (60%) of 20 subjects. None of the 33 had constipation. Our results suggest that PMGLEPT is safe with acceptable outcome in the short- to mid-term. However, careful long-term follow-up is mandatory as there appears to be a relatively high incidence of staining/soiling on short- to mid-term follow-up.

Child, Preschool↗
PubMed2005

Disseminated mixed intestinal dysmotility (DMID): a new intestinal ganglion cell disorder?

We experienced two cases with disseminated HP and IND occurring with normal bowel in between (disseminated mixed intestinal dysmotility--DMID) and postulate whether it could be classified as a new intestinal motility disorder. Our cases, both boys, died at 3 and 7 months, respectively. Both had irregular stool passage, and abdominal distention with bilious vomiting since birth. On barium enema, both had rigid distal ileum and colon with narrow lumens, with dilated and atonic proximal ileum and jejunum. An ileostomy was created on days 3 and 2 of life, respectively, however, they did not function and jejunostomies were created, which also did not function well. Both boys died after repeated episodes of severe enterocolitis. In each case, three 10 cm specimens were obtained randomly from the jejunum and ileum, and two 5 cm specimens were obtained randomly from each of the ascending colon, transverse colon, descending colon, and rectum and treated with hematoxylin and eosin (H & E) staining, acetylcholine esterase (AchE) histochemistry, and protein gene product 9.5 (PGP9.5) and neural cell adhesion molecule (NCAM) immunohistochemistry for histopathologic assessment. All specimens showed a mixture of disseminated IND and HP, with normal intestine in between. There was abnormal expression of NCAM activity in the intestinal smooth muscle layers in small and large intestine. This is the first report about disseminated IND and HP occurring with normal bowel in between (DMID) and we suggest it should be classified as a new intestinal motility disorder. The present findings demonstrate that patients with DMID have a complicated abnormality of NMJ that may directly influence bowel motility and prognosis according to the severity of the abnormality.

Digestive System Abnormalities↗
PubMed2005

Novel procedures for enhancing high jejunal atresia repair: bilateral side-plication and plication before anastomosis.

In high jejunal atresia (HJA), discrepancy between the diameters of the proximal and distal jejunum can often be significant and cause major anastomotic complications. We developed 2 novel procedures to enhance conventional jejuno-jejunostomy (JJ): bilateral side-plication during JJ (BSP): plication of both lateral aspects of the dilated proximal jejunum, and jejunal plication before JJ (pre-P): plication of the jejunum proximal to the planned JJ site along the anti-mesenteric line. We used BSP in a neonate with a membranous stenosis 5 cm distal to the duodeno-jejunal flexure, and pre-P in 2 neonates, both with HJA and hugely dilated proximal jejunum. By using BSP, the jejunum could be plicated symmetrically near the closed jejunotomy, allowing the caliber change at the closed jejunotomy to be smooth without any kinking. If simple anti-mesenteric plication had been performed instead, proximal-to-distal kinking caused by closing the jejunotomy site transversely after the membrane was excised could have worsened. By using pre-P, the caliber change across the JJ could be made smooth and symmetric. If plication had been performed along the anti-mesenteric line after completing the JJ, the proximal jejunum near the JJ would have become asymmetrical causing the JJ to become kinked. Postoperatively, there were no JJ-related complications, and all subjects are well after a mean follow-up period of 3.0 years. Our novel procedures are simple and appear to enhance JJ by controlling kinking at the JJ site.

Dilatation, Pathologic↗
PubMed2005

Mixed type I and II choledochal cyst: a new clinical subtype?

Traditionally, choledochal cyst (CC) is classified into five types according to Todani's classification. Of 356 cases of CC treated at our institute since 1965, we experienced four cases of mixed type I and II choledochal cyst (MTCC). The incidence of MTCC was 1.1%. All four patients had a fusiform common bile duct (CBD) with a diverticulum originating from the mid-portion of the CBD. The cystic duct drained into the right side of the diverticulum. All had pancreaticobiliary malunion (PBMU). All presented with recurrent abdominal pain. MTCC was suggested on ultrasonography or computerized tomography and confirmed by endoscopic retrograde cholangiopancreatography (three cases) or magnetic resonance cholangiopancreatography (one case). Age at surgery ranged from 3 to 12 years. All had hepaticoenterostomy, and total excision of the CC/diverticulum/gallbladder. There were no complications and all cases are currently well. In all cases, histopathology showed that the wall of the diverticulum was identical to the CBD. Although the incidence of MTCC is very low, pediatric surgeons should be aware of it as a new subtype of CC. Based on our experiences and a review of the literature, we suggest that its etiology does not affect treatment because the surgical management of choice is the same as for type I CC.

Biliary Tract↗
PubMed2005

Complete innervation profile of whole bowel resected at pull-through for Hirschsprung's disease. Unexpected findings.

We used Acetylcholinesterase (AchE) staining and neural cell adhesion molecule (NCAM) immunoreactivity to examine such resected lengths to determine the complete innervation profile of resected bowel in Hirschsprung's disease (HD). Resected specimens of colon obtained at pull-through surgery from 15 patients with HD [short type (S-type: n=5), recto-sigmoid type (RS-type: n=5), long type (L-type: n=5)] were sectioned at 1.5 cm intervals and stained conventionally with AchE histochemistry and NCAM immunohistochemistry. The number of positive nerve fibers (PNFs) in the lamina propria and smooth muscle layers was assessed on a scale of 0 to 3 where 0 meant no PNF and 3 meant many PNFs. The three types of HD had different AchE and NCAM innervation profiles, especially the L-type. There were also different AchE and NCAM innervation patterns seen within the same aganglionic or transitional segments of bowel depending on the site of sampling. The mean proportion of transitional segment in resected specimens from RS-type HD was significantly larger than that of S-type HD (P<0.001) although the proportion of aganglionic segments from S- and RS-type HD were almost the same. Our results suggest that the etiology of L-type HD may be different from the etiology of S- and RS-type HD because of different innervation profiles. Because segments of the excised bowel would appear to have different innervation patterns depending on whether the specimen is sampled proximally or distally, it is important to record the exact site of sampling to allow valid comparisons between types of HD to be made.

Acetylcholinesterase↗
PubMed2005

Cysts of the ejaculatory system: a report of two cases.

We report two cases of rare cystic dilatations of the ejaculatory system. In case 1, a 6-month-old boy was referred to us for the management of recurrent epididymo-orchitis (E-O) complicating open drainage and a colostomy was performed elsewhere for a purulent rectal discharge thought to be rectal duplication. Diagnostic imaging showed a retrovesical cyst. Urethrocystoscopy showed a swelling of the verumontanum. No fistula was seen between the cyst and rectum on colonoscopy. At laparotomy, both ejaculatory ducts and seminal vesicles were found to be fused into a mass with cystic dilatation of the ejaculatory duct. Intraoperative histopathology of the cyst identified a metaplastic epithelial lesion. The cyst was excised with bilateral vasoligation. Since surgery, 8 years ago, urination and defecation have been normal. In case 2, a 4-month-old boy presented with fever and a swollen right scrotum. Ultrasonography showed a retrovesical cyst. Right grade IV vesicoureteral reflux diagnosed on voiding cystourethrography was treated by ureter reimplantation (Cohen) but complicated by recurrent E-O. Urethrocystoscopy with retrograde contrast via the utriculus showed that the cyst opened on the verumontanum, that both ejaculatory ducts opened into the cyst, and there was reflux into the right vas deferens. Right vasoligation alone was performed through a scrotal approach. Although the cyst was not excised, there has been no recurrence of E-O nor enlargement of the cyst for 6 years. Cysts of the ejaculatory system should be considered in the etiology of recurrent E-O in prepubertal children and a high index of awareness is recommended.

Cystoscopy↗
PubMed2005

An extremely rare case of symptomatic right hepatic duct diverticulum located outside the liver.

Symptomatic hepatic duct diverticulum located outside the liver is extremely rare, with only one reported case. We encountered this anomaly and present our experience, focusing on surgical management. A 17-year-old-girl was referred to our institute because of recurrent right upper quadrant pain. At presentation, serum amylase, lipase, bilirubin, and transaminases were normal. White blood cell count and C-reactive protein were slightly raised. Ultrasonography and magnetic resonance cholangiopancreatography (MRCP) revealed a diverticulum-like lesion on the right side of the bile duct system appearing to overlap the gallbladder. The provisional diagnosis was type II choledochal cyst. Pancreaticobiliary malunion (PBMU) could not be confirmed on MRCP. The origin of the lesion could not be identified initially at laparotomy, but after repeated intraoperative cholangiography (IC) studies, the lesion was found to originate from a normal-sized right hepatic duct via a narrow duct. It was relatively easy to ligate the narrow duct and treat the lesion smoothly. IC also showed that the common bile duct was not dilated and that PBMU was absent. Histopathology showed the lesion to be a diverticulum of the bile duct epithelium. This is only the second report of a symptomatic hepatic duct diverticulum located outside the liver. Based on our experience, IC is particularly useful for the complete understanding of anomalous hepatobiliary duct anatomy and for planning surgical treatment.

Adolescent↗
PubMed2005

Primary sclerosing cholangitis in which differential diagnosis from gallbladder carcinoma was difficult.

We report a case of localized primary sclerosing cholangitis (PSC) which was difficult to distinguish from gallbladder carcinoma. A 75-year-old woman with elevated serum bilirubin was hospitalized and underwent endoscopic nasobiliary drainage (ENBD). There was no history of diseases such as gallbladder stone, pancreatitis, or ulcerative colitis. Cholangiography through the ENBD tube showed localized stenosis of the common bile duct; the gallbladder could not be seen. Angiography showed no encasement of the hepatic artery. Ultrasonography showed a tumor in the cystic duct, and the tumor had invaded the gallbladder and common bile duct. We diagnosed gallbladder carcinoma on radioimaging, and performed an S4aS5 subsegmentectomy of the liver and resection of the extrahepatic biliary tree. Pathologically, no malignant cells were detected, and fibrosis around bile ducts and infiltration of inflammatory cells into hepatic tissue were found. It is well known that PSC is sometimes difficult to differentially diagnose from cholangiocarcinoma. Our case is of high interest because ultrasonography showed findings suggestive of gallbladder carcinoma. It is therefore necessary to keep the possibility of PSC in mind for the diagnosis and treatment of such localized biliary stenosis.

Aged↗
PubMed2005

A tumor in the medulla oblongata producing beta-HCG and AFP.

A 23 year-old woman presented with dysarthria, hoarseness, dysphasia, ataxia and dyspnoea. MRI showed a mass of heterogeneous intensity at the dorsal medulla oblongata. Laboratory studies revealed high serum alpha-fetoprotein (AFP) and beta-subunit human chorionic gonadotropin (beta-HCG) levels. No other tumours were found on systemic investigation. An intracranial non-germinomatous germ cell tumour (NGGCT) was strongly suspected. The patient received combination chemotherapy using ifosfamide, cisplatin, and etoposide and local irradiation to a total of 52 Gy. Serum AFP and beta-HCG levels normalized after four cycles of chemotherapy and she became asymptomatic apart from mild postural hypotension. A follow-up MRI showed only a tiny residual lesion in the medulla oblongata, which has been stable for more than three years. Surgical resection should be carefully considered in patients with brainstem tumours with elevation of serum tumour markers as chemo- and radiotherapy may be effective for brainstem NGGCT.

Adult↗
PubMed2005

Bladder stone formation after sigmoidocolocystoplasty: statistical analysis of risk factors.

PURPOSE: Bladder stone formation (BSF) after sigmoidocolocystoplasty (SCP) is a major source of morbidity. The authors identify risk factors and analyze them statistically. METHODS: Medical records of 106 patients who had SCP at our institute were reviewed to examine the incidence of post-SCP BSF, the stone removal method and length of follow-up. The primary underlying pathological conditions were myelomeningocele in 103 patients and other conditions in 3. Risk factors for BSF were statistically assessed by comparing cases with and without BSF. RESULTS: Bladder stone formation occurred in 20 (18.9%) of 106 patients (BSF group). The remaining 86 did not have stones (NBSF group). Mean age at SCP was 11.7 years in the BSF group and 10.2 years in the NBSF group. Mean follow-up was 12.0 years in the BSF group and 11.0 years in the NBSF group. BSF developed after a mean of 30.3 +/- 25.6 months after SCP. Twenty-two stone removal procedures were performed in the BSF group and spontaneous evacuation occurred in 4 instances. Once stone free, BSF recurred in 4 patients. Although differences between the 2 groups with respect to sex, age at SCP, follow-up period, bladder capacity, bladder compliance, incidence of gram-negative bacteriuria, incidence of gram-positive coccus bacteriuria, electrolytes, frequency of urinary catheterization, post-SCP incidence of vesicoureteric reflux, and incidence of ureteric reimplantation were not statistically significant, differences in the incidence of spontaneous micturition, bladder neck tightening procedures, or gram-positive bacillus bacteriuria, or frequency of bladder irrigation were all statistically significant (P < .05 in all, Fisher's Exact test). CONCLUSIONS: The authors are the first to statistically analyze a wide range of varying risk factors for BSF. BSF would appear to be common after SCP.

Adolescent↗
PubMed2005

Optimum prednisolone usage in patients with biliary atresia postportoenterostomy.

PURPOSE: Prednisolone is used routinely after portoenterostomy (PE) in patients with biliary atresia (BA). The authors reviewed their patients with BA post-PE to assess prednisolone protocols. METHOD: Severity of fibrosis at PE (moderate or severe), age at PE (30-70 days), size of bile ductules in the fibrotic biliary remnant at the porta hepatis (>100 microm), and type of BA (uncorrectable type) were used as criteria for selecting 63 subjects from our patients with BA post-PE. Subjects were divided into 5 groups according to prednisolone dosage: group 1, no prednisolone; groups 2 to 4, single courses of intravenous prednisolone commencing on day 7 post-PE administered in decreasing dose for 3 days each as follows: group 2, 6, 4, and 2 mg; group 3, 10, 5, and 2.5 mg; group 4, 20, 15, 10, 5, and 2.5 mg; group 5, same as group 4, but stool color was used to monitor bile excretion and a course was restarted from 20 mg whenever stools began to turn pale. If necessary, single courses were repeated until serum total bilirubin was less than 2.0 mg/dL. Protocol efficacy was assessed by comparing the number of patients who became jaundice free, the period taken to become jaundice free, and the incidence of side effects related to prednisolone. RESULTS: The number of patients who became jaundice free in the no prednisolone group (group 1, 7/12 or 58.3%) was not significantly different from the number in the single-course groups (group 2, 8/12 or 66.6%; group 3, 10/13 or 76.9%; and group 4, 11/15 or 73.3%). The number in the stool-monitored group (group 5, 10/11 or 90.9%) was significantly greater (P < .05). The mean period taken to become jaundice free in group 1 (82.6 +/- 29.1 days) was not significantly different from the single-course groups (group 2, 74.5 +/- 29.3 days; group 3, 49.6 +/- 19.8 days; and group 4, 48.3 +/- 26.0 days). The mean period taken in the stool-monitored group (group 5, 33.3 +/- 6.4 days) was significantly shorter (P < .05). The number of subjects who developed cholangitis after becoming jaundice free was not significantly different (group 1, 2/7; group 2, 2/8; group 3, 2/10; group 4, 2/11; group 5, 2/10). There were no prednisolone-related complications identified in any subject. CONCLUSIONS: These results provide strong evidence that large-dose prednisolone therapy with stool color monitoring of bile flow has a positive impact on the time taken for patients with BA post-PE to become jaundice free and the number of patients who remain jaundice free.

Anti-Inflammatory Agents↗
PubMed2005

Graft serosectomy in adult small bowel transplantation without vascular reconstruction in rats improves graft survival by induction of vascular endothelial growth factor.

PURPOSE: The aim of this study was to assess whether adult small bowel grafts (ASBGs) can survive transplantation without vascular reconstruction if graft serosectomy (SS) is performed. METHODS: Syngeneic ASBG transplants were performed in 85 Lewis rats. The entire serosa was removed just before transplantation in the SS group (n = 50) and left intact in the nonserosectomy group (n = 35). Transplanted ASBG was harvested 1, 3, 5, 7, 14, 21, or 28 days after transplantation and studied using staining with hematoxylin-eosin, immunohistochemistry for protein gene product 9.5, S-100, CD34 and vascular endothelial growth factor (VEGF), and quantification of VEGF messenger RNA (mRNA). Adult small bowel graft viability was assessed blindly using a mucosal surface expansion score (0, no mucosa; 1, mucosa on one fourth of graft; 2, mucosa on one half of graft; 3, mucosa on three fourths of graft; and 4, circumferential mucosa on graft). RESULTS: No rejection was identified in any ASBG. Average mucosal surface expansion score and VEGF mRNA expression were significantly higher in the SS group (both P < .01). Vascular endothelial growth factor protein was detected in enterocytes from day 3 posttransplant in the SS group. Distribution of protein gene product 9.5 and S-100 was normal in SS-group ASBG. CONCLUSIONS: Our results suggest that SS allows VEGF mRNA and, subsequently, VEGF protein in ASBG to be induced very soon after transplantation, which may contribute to the survival of ASBG transplanted without vascular reconstruction.

Animals↗
PubMed2005

Occipitoparietal benign osteoblastoma: should entire lesion be resected when magnetic resonance images reveal wide abnormal signal intensity in surrounding bone marrow?

BACKGROUND: Benign osteoblastoma is an uncommon primary bone tumor that usually affects long bones and the vertebral column. Its occurrence in the calvarium is rare. Despite the characteristically benign nomenclature of osteoblastoma, it sometimes recurs with the possibility of transforming into a malignant form after an incomplete resection. Therefore, radical resection is recommended whenever possible. However, it has not been clarified whether the adjacent bones should also be completely resected when magnetic resonance (MR) images reveal abnormal signal intensity in the bone marrow. CASE DESCRIPTION: Presented in this case report is a 12-year-old boy with occipital tenderness associated with occipitoparietal bone tumor. Neuroradiological studies demonstrated a solid tumor located in the occipital bone extending over the right parietal bone. Magnetic resonance images further revealed abnormal signal intensity in the bone marrow of the entire occipital and bilateral parietal bones. Macroscopically, the calvarial bone adjacent to the solid tumor appeared to be reddish, but it was not covering the entire area, contradicting the abnormal intensity found on the preoperative MR images. The resected area was determined according to macroscopic findings, and bones with normal color tone were preserved. Because histological examination did not clearly indicate tumor invasion at the margin of the resection site, no additional therapy was given. Although MR images revealed abnormal intensity in the bone marrow of the surgical margin immediately after the operation, the intensity had been normalized by degrees and there was no evidence of recurrence during a follow-up period of 34 months. This may suggest that bone marrow lesion showing abnormal intensity was edema rather than tumor invasion. CONCLUSIONS: The authors conclude that total resection, including a bone marrow lesion, is not always necessary for benign osteoblastoma. Macroscopic findings that show an abnormal color tone of the cortex could be a good indicator in revealing tumor activity invading bone marrow.

Bone Marrow Neoplasms↗