Bone Sarcoma WithEWSR1-NFATC2Fusion: Sarcoma With Varied Morphology and Amplification of Fusion Gene Distinct From Ewing Sarcoma

Ewing sarcomas are typified by EWSR1 fusion to ETS gene family members. Tumors with fusion partners other than ETS family members and atypical histologic features pose significant diagnostic challenges and controversies as to their classification. In this article, we report a tumor with EWSR1-NFATC2 fusion in the left femur of a 43-year-old man and with unusual morphologic features that resemble undifferentiated high-grade sarcoma. Analysis together with reported cases in the literature shows that tumors with EWSR1-NFATC2 exhibit distinctive clinicopathologic features, including predilection for young male adults, highly variable histology that varies from round cell tumors frequently associated with nuclear irregularity, short spindle cells with nuclear pleomorphism, to myoepithelial tumor-like with or without myxohyaline matrix. They show variable positivity to CD99, frequent expression of cytokeratins, and consistent high-level amplification of EWSR1-NFATC2 fusion gene with distinctive gene expression profile. These tumors thus deserve classification separate from Ewing sarcoma.

Heat Damage Zones Created by Different Energy Sources Used in the Treatment of Benign Prostatic Hyperplasia in a Pig Liver Model

INTRODUCTION

There are different types of transurethral prostatic surgeries and the complication profiles are different. This study aims to compare the heat damage zones (HDZ) created by five different technologies in a pig liver model.

MATERIALS AND METHODS

Monopolar resection, bipolar resection, electrovaporization, and Greenlight™ lasers of 120 and 180 W were used to remove fresh pig liver tissue in a simulated model. Each procedure was repeated in five specimens. Two blocks were selected from each specimen to measure the three deepest HDZ.

RESULTS

The mean of HDZ was 295, 234, 192, 673, and 567 μm, respectively, for monopolar resection, bipolar resection, electrovaporization, Greenlight laser 120 W, and Greenlight laser 180 W, respectively. The Greenlight laser produced one to three times deeper HDZ than the other energy sources (p=0.000).

CONCLUSION

Both 120 and 180 W Greenlight lasers produced deeper HDZ than the other energy sources. Urologists need to be aware of HDZ that cause tissue damage outside the operative field.

Prognostic factors associated with clear cell sarcoma in 14 Chinese patients

PURPOSE. To identify prognostic factors associated with clear cell sarcomas in 14 Chinese patients. METHODS. Medical records of 7 men and 7 women (mean age, 36 years) with histologically confirmed clear cell sarcoma of tendons and aponeuroses were reviewed. Patient demographics, tumour characteristics, and treatment modalities were retrieved. Prognostic factors associated with favourable 5-year survival were determined. RESULTS. The most affected sites were the thigh (n=5) and the foot (n=4); the mean time from symptom onset to diagnosis was 9.5 months. The tumour stage at diagnosis was IIA in 8 patients, IIB in 2, and III in 4. The mean tumour size was 4.5 cm in diameter. One patient was lost to follow-up. For the remaining 13 patients, the mean time to disease-related mortality was 2.5 years. Nine patients had distant metastases; the most common sites were lungs and pleura (n=7), followed by distant lymph nodes (n=4), bone (n=2), pericardium (n=2), and brain (n=1). All patients underwent surgical excision. Three women and one man (mean age, 27 years) attained 5-year disease-free survival. All had stage IIA tumours at diagnosis. Their mean tumour size was 1.75 cm in diameter, which was significantly smaller than that of all patients (4.5 cm). Tumour size of ≤ 2.5 cm in diameter (p=0.004) and stage IIA tumour at diagnosis (p=0.04) were significant prognostic factors for 5-year survival. CONCLUSION. Tumour size of ≤ 2.5 cm and early stage tumour are associated with 5-year disease-free survival. Early detection is crucial for the prognosis of clear cell sarcomas.

Pigmented ependymoma with lipofuscin and neuromelanin production

We report an unusual case of ependymoma with pigmentation, a phenomenon that has only been described in a few cases, to our knowledge. This tumor occurred in the fourth ventricle of a 45-year-old man. It showed the typical histologic appearance of ependymoma with perivascular pseudorosettes and rare ependymal rosettes. Some tumor cells contained brown cytoplasmic pigment, which was shown histochemically to represent a mixture of lipofuscin and neuromelanin. The pigment was positive for acid-fast and periodic acid-Schiff stains and was also focally positive for Masson-Fontana and Schmorl stains (bleached by pretreatment with potassium permanganate). In addition, some other tumor cells showed a signet ring morphology as a result of prominent intracytoplasmic vacuolation. Immunohistochemically, all the tumor cells expressed glial fibrillary acidic protein, and rare pigmented tumor cells also expressed HMB-45. Ultrastructural examination showed irregularly shaped heterogeneous electron-dense bodies corresponding to the pigment, and the cytoplasmic vacuoles were formed by dilatation of intracytoplasmic lumens lined by microvilli. Since lipofuscin production can occur in normal ependymal cells and neuromelanin has been suggested to be a melanized form of lipofuscin, it is not surprising that these 2 pigments can be found in ependymoma. In all the previously reported cases, the pigment was shown to represent melanin only. In our case, the HMB-45 positivity in rare tumor cells indicated that there might also be a minor melanin component in the pigment in addition to lipofuscin and neuromelanin.

Can pulmonary sclerosing haemangioma be accurately diagnosed by intra-operative frozen section?

AIMS

Pulmonary sclerosing haemangioma is a rare benign tumour with a characteristic variegated histological pattern. In this retrospective study we aimed to identify features that can aid in making a correct diagnosis and avoiding potential pitfalls at the time of intra-operative frozen section.

METHODS AND RESULTS

Twenty cases of pulmonary sclerosing haemangioma with intra-operative frozen section were reviewed. The four major histological patterns (solid, sclerotic, papillary and haemorrhagic) were found in various combinations in the frozen sections. In 17 cases, three or more patterns were present. There could be focal areas mimicking epithelioid haemangioendothelioma or carcinoid tumour. Intra-operative imprint/scrape cytology served as a helpful adjunct in confirming the cytological blandness, although occasional atypical cells could be present. An intra-operative frozen section diagnosis of 'sclerosing haemangioma' or 'benign tumour' was given in 14 cases; the diagnosis was deferred in six cases. Retrospective analysis of the deferred cases showed that a definitive intra-operative diagnosis could have been made in three, because three or more major histological patterns were present. One case showed a pure papillary pattern at frozen section, mimicking the appearance of papillary adenocarcinoma (primary or secondary), bronchioloalveolar carcinoma, epithelioid mesothelioma or papillary adenoma; two tumours from a patient with multicentric disease showed widespread significant cytological atypia in the tumours raising a serious consideration of malignancy.

CONCLUSION

A diagnosis of pulmonary sclerosing haemangioma can be made at intra-operative frozen sections in most cases based on the tumour circumscription and variegated histological patterns. When only a single histological pattern is identified or when there is significant cytological atypia, distinction from other tumours can be problematic, and the diagnosis is best deferred.

Nodular fasciitis: MRI appearance and literature review

OBJECTIVE

To describe the MRI features of nodular fasciitis and to review the clinical, MRI and histologic aspects of the tumor.

DESIGN AND PATIENTS

Three patients with biopsy-proven nodular fasciitis were selected for a retrospective study. A literature review was also carried out.

RESULTS AND CONCLUSIONS

All the lesions appeared slightly hyperintense to skeletal muscle on T1-weighted images, and hyperintense on T2-weighted images with fat saturation [either frequency saturation or Short TI Inversion Recovery (STIR) sequences]. Two enhanced homogeneously after intravenous gadolinium, whereas the third showed heterogeneous enhancement with a nonenhancing area. Despite the difference in enhancing patterns, the histologic appearances of these lesions were similar. Our study shows that the MRI appearance of nodular fasciitis may not be related to the location of lesion. It is thought that the age of nodular fasciitis may reflect its gross morphology, and it is possible that the MRI and histologic appearances could correlate with the age of the lesion, but it would require a larger series to evaluate this concept.