Tomoaki Torigoe

A case of secondary malignant giant-cell tumor of bone with p53 mutation after long-term follow-up.

A 46-year-old man was admitted to the hospital with a recurrent giant-cell tumor of the distal femur. This was his fourth recurrence, and it had occurred 16 years after his last treatment. The resected recurrent tumor was histologically determined to be a conventional giant-cell tumor. However, a single lung metastatic lesion and local recurrence were noticed 6 months after the resection, both of which were surgically excised. The lung lesion was histologically determined to be an implantation of giant-cell tumor, whereas the local recurrent lesion contained a clearly separated fibrosarcomatous area within the conventional giant-cell tumor. Immunohistochemistry showed diffuse and strong p53 expression in the fibrosarcomatous area. Direct sequencing revealed a p53 mutation in the sarcomatous area and a recessive mutant signal in the conventional area. The lung lesion also contained the same p53 mutation. Identification of the p53 mutation may help in diagnosing potential malignant transformation of giant-cell tumor.

Intraneural lipomatous tumor of the median nerve: Three case reports with a review of literature

INTRODUCTION Intraneural lipoma and fibrolipomatous hamartoma of the nerve are rare soft tissue tumors that most commonly occur in the forearm and the wrist, and particularly within the median nerve. When the lesions are large enough, they may cause progressive compression neuropathy. They are distinct entities each other with different clinical and radiological findings and thereby need different surgical treatments. PRESENTATION OF CASE We report here 3 cases of intraneural lipomatous tumors of the median nerve (1 case of intraneural lipoma and 2 cases of fibrolipomatous hamartoma). DISCUSSION All patients were surgically treated successfully with complete excision for intraneural lipoma and with carpal tunnel releases for the both fibrolipomatous hamartomas. CONCLUSION A careful preoperative planning is necessary for the optimal treatment by distinguishing whether it is a resectable or non-resectable tumor based on the clinical and radiological findings, because they have characteristic findings each other.

A case of de novo secondary malignant giant-cell tumor of bone with loss of heterozygosity of p53 gene that transformed within a short-term follow-up

A 19-year-old woman was admitted to the hospital with a complaint of right wrist pain. A plain radiograph showed an osteolytic lesion in the right distal radius. Surgical treatment with curettage and bone grafting was performed under the clinical diagnosis of a giant-cell tumor. However, local recurrence was noticed 6 months after the treatment, and the curettage and bone graft were performed again. The histology of the recurrent lesion revealed a malignant giant-cell tumor that was entirely composed of highly atypical stromal cells and tumor giant cells. After a retrospective review of the primary lesion, it was found to also contain a small focus of pleomorphic cells within the conventional giant-cell tumor. Immunohistochemical and genetic analysis revealed p53 overexpression in the tumor giant cells and loss of heterozygosity of p53 gene only in the recurrent tumor; thus, a diagnosis of secondary malignant giant-cell tumor was finally made. The patient underwent systemic chemotherapy along with curettage and cryosurgery using liquid nitrogen. It is now 1 year and 4 months after the last treatment, and the patient is well and alive with no evidence of the disease. Identification of p53 genetic alteration may help in diagnosing malignant giant-cell tumor.

A clinicopathological study of giant cell tumor of small bones

Abstract Background and purpose. Giant cell tumor (GCT) of the small bones (small-bone GCT) is usually rare and considered somewhat different from conventional GCT. The purpose of this study was to investigate and report the clinicopathological features of 11 cases with small-bone GCT. Materials and methods. Patient information was obtained with the help of questionnaires. X-rays and paraffin blocks obtained from several institutions were clinically, radiographically, and histologically evaluated. Results. Small-bone GCT was observed in younger patients compared to conventional GCT; 5 of the 11 (45%) patients were below 20 years of age, whereas the corresponding figure for all GCT patients is 16% in Japan. Excessive cortical bone expansion is a special feature. There were two cases of recurrence and one case of lung metastasis; the primary lesion was in the hand for all three cases. In contrast, no primary lesion of the foot recurred or metastasized. Varying degrees of positive p63 immunostaining were observed in all examined cases (n = 9) of small-bone GCT but were negative in case of giant cell reparative granuloma (GCRG) and solid variant of aneurysmal bone cyst (ABC). One case that demonstrated high-intensity positive staining had two episodes of recurrence. Conclusion. Small-bone GCT tends to develop in younger patients than does conventional GCT. Primary GCTs of the hand may be biologically more aggressive than those of the feet. The p63 immunostaining may be useful not only for differential diagnosis but also for prognostication of small-bone GCT.

Primary pleomorphic liposarcoma of bone: MRI findings and review of the literature

Primary liposarcoma of bone is exceedingly rare. We report a case of primary pleomorphic liposarcoma in the humerus of a 38-year-old female. Radiographs demonstrated an expansile and osteolytic lesion extending from the head to the proximal part of the shaft in the right humerus. MR study showed a defined lesion in the humerus. The lesion had an iso-signal intensity and partial high-intensity lesion on T1-weighted images and a heterogeneous high signal intensity on T2-weighted images. Wide resection and proximal humeral endoprosthesis replacement were performed. Final pathological diagnosis of the lesion was pleomorphic liposarcoma. This is the second reported case of pleomorphic liposarcoma of the bone, and the first case presenting MRI findings for liposarcoma of bone.

Xanthoma of bone associated with lipoprotein lipase deficiency

Lipoprotein lipase (LPL) deficiency is an extremely rare congenital metabolic disorder with an accumulation of chylomicrons in the blood. We encountered a patient with an LPL deficiency leading to multiple bone xanthomas associated with hyperlipidemia. Radiographs and MRI of the humerus and femur revealed symmetrical bone lesions, and there is a possibility that these symmetrical lesions may therefore be a characteristic feature for this disorder.

p63 as a prognostic marker for giant cell tumor of bone

Abstract Background and purpose. Giant cell tumor of bone (GCT) is sometimes difficult to distinguish from other giant-cell-rich tumors such as chondroblastoma (CHB) and aneurysmal bone cyst (ABC). The usefulness of p63 as a diagnostic marker for GCT is controversial. While there have been no reports about p63 as a prognostic marker for local recurrence, various p63-positive rates in GCT have been reported. The purpose of this study was to investigate retrospectively whether p63 is useful as a diagnostic marker and/or a prognostic marker for local recurrence of GCT. Methods. This study included 36 patients diagnosed with either GCT (n = 16), CHB (n = 9), ABC (n = 7), or non-ossifying fibroma (NOF) (n = 4). p63 immunostaining was performed for all specimens. The mean p63-positive rate was compared with the four diseases and between the recurrent and non-recurrent cases of GCT. Results. Although the mean p63-positive rate for GCT (36.3%) was statistically higher than that of all other diseases examined (CHB: 15.2%; ABC: 5.8%; NOF: 3.4%), p63 was not specific for GCT. The mean p63-positive rate for recurrent GCT cases (73.6%) was statistically higher than that for non-recurrent cases (29.1%). Conclusion. In the diagnosis of GCT, p63 is a useful but not a conclusive marker. However, p63 did appear to indicate the biological aggressiveness of GCT. Therefore, p63 may help surgeons to estimate the risk of recurrence after surgery and help them to choose the best treatment for each GCT case.

Low-grade myofibroblastic sarcoma of the distal femur

INTRODUCTION Low-grade myofibroblastic sarcoma (myofibrosarcoma) is described to be a distinct atypical myofibroblastic tumor often with fibromatosis-like features and predilection for head and neck. Low-grade myofibroblastic sarcoma of bone is extremely rare. PRESENTATION OF CASE A 50-year-old woman was admitted to our hospital because she had experienced right knee pain for 2 years. Plain radiography showed a honeycombed lesion on the right distal femur, and computed tomography showed a bone tumor with cortex destruction invading the soft tissue. A biopsy specimen from the intraosseous lesion showed a hypocellular area of spindle cell proliferation with dense collagen deposition, which is reminiscent of a histological feature of desmoplastic fibroma. However, histological examination of the extraosseous lesion indicated a slightly hypercellular area containing scattered spindle-shaped atypical cells with enlarged nuclei, suggestive of low-grade sarcoma. Spindle-shaped atypical cells were immunohistochemically positive for SMA. A final diagnosis of low-grade myofibroiblastic sarcoma of the bone was made from a surgically resected specimen. DISCUSSION The patient was alive and well with no evidence of disease at 15 months after the surgery without any additional therapy. CONCLUSION Extensive sampling of a tumor may be necessary to determine the true nature of the tumor and to make an accurate diagnosis.

Bone versus soft-tissue sarcomas in the elderly

Purpose. To compare survival rates in the elderly with bone versus soft-tissue sarcomas. Methods. Records of 12 men and 8 women aged 70 to 91 (mean, 77) years with bone or soft-tissue sarcomas were retrospectively reviewed. The grade, size, location, and stage of the sarcomas, as well as their surgical margins, treatment modalities, local recurrence, metastasis, and prognosis were recorded. The mean follow-up period was 37 (range, 2–137) months. Their 5-year survival rates were estimated using the Kaplan-Meier method, and compared with 110 younger controls aged 9 to 69 (mean, 45) years during the same period. There was no significant difference between the older patients and younger controls regarding tumour grading (p=0.068, Chi squared test), stage, and pathological diagnosis. Results. Six patients had bone and 14 had soft-tissue sarcomas. Of the 6 bone sarcomas, 3 were malignant fibrous histiocytomas, 2 were osteosarcomas, and one was a chordoma; all were high grade, except for the chordoma. Of the 14 soft-tissue sarcomas, 9 were malignant fibrous histiocytomas, 3 were myxofibrosarcomas, one was a liposarcoma and one an extraskeletal osteosarcoma; all were high grade except for 2 of the myxofibrosarcomas and the liposarcoma. Of the 110 younger controls, 30 had bone and 80 had soft-tissue sarcomas; 44 were low grade and 66 were high grade. The 5-year survival rate was significantly lower in older patients than in younger controls (35% vs 65%, p=0.048). Regarding bone versus soft-tissue sarcomas, the 5-year survival rate was not significantly different among older patients (0% vs 52%, p=0.068) or younger controls (61% vs 66%, p=0.863). The difference was also not significant for older patients versus younger controls with bone sarcomas (0% vs 61%, p=0.284) or soft-tissue sarcomas (52% vs 66%, p=0.368), for older patients with high- versus low-grade sarcomas (17% vs 100%, p=0.314), for older patients with sarcomas located in the limbs versus the trunk (39% vs 38%, p=0.233), as well as for older patients versus younger controls with low-grade sarcomas (100% vs 92%, p=0.512) or high-grade sarcomas (17% vs 46%, p=0.269). Conclusion. Survival rates tend to be lower in older patients with sarcomas, especially when the sarcoma is of bone and high grade.

Pedicle freezing with liquid nitrogen for malignant bone tumour in the radius: a new technique of osteotomy of the ulna

We describe a new technique of pedicle freezing of the distal radius with malignant bone tumour and osteotomy of the normal ulna. The distal radius was sufficiently elevated to enable freezing without damaging adjacent tissues by releasing the distal radio-ulnar and radio-carpal joint and cutting the middle third of the ulna. The distal radius (including the tumour) was soaked in liquid nitrogen and the defect filled with iliac grafts. The ulna was repaired with plate and screws and was united at month 2. There was no local recurrence and the postoperative function score was 93%. This technique decreases the risk of non-union of the osteotomy site of the tumorous bone.