Microscopic histological characteristics of soft tissue sarcomas: analysis of tissue features and electrical resistance.

Tissue electrical conductivity is correlated with tissue characteristics. In this work, some soft tissue sarcomas (STS) excised from patients have been evaluated in terms of histological characteristics (cell size and density) and electrical resistance. The electrical resistance has been measured using the ex vivo study on soft tissue tumors electrical characteristics (ESTTE) protocol proposed by the authors in order to study electrical resistance of surgical samples excised by patients in a fixed measurement setup. The measurement setup includes a voltage pulse generator (700 V, 100 µs long at 5 kHz, period 200 µs) and an electrode with 7 needles, 20 mm-long, with the same distance arranged in a fixed hexagonal geometry. In the ESTTE protocol, the same voltage pulse sequence is applied to each different tumor mass and the corresponding resistance has been evaluated from voltage and current recorded by the equipment. For each tumor mass, a histological sample of the volume treated by means of voltage pulses has been taken for histological analysis. Each mass has been studied in order to identify the sarcoma type. For each histological sample, an image at 20× or 40× of magnification was acquired. In this work, the electrical resistance measured for each tumor has been correlated with tissue characteristics like the type, size and density of cells. This work presents a preliminary study to explore possible correlations between tissue characteristics and electrical resistance of STS. These results can be helpful to adjust the pulse voltage intensity in order to improve the electrochemotherapy efficacy on some histotype of STS.

Electrical resistance of human soft tissue sarcomas: an ex vivo study on surgical specimens.

This paper presents a study about electrical resistance, which using fixed electrode geometry could be correlated to the tissue resistivity, of different histological types of human soft tissue sarcomas measured during electroporation. The same voltage pulse sequence was applied to the tumor mass shortly after surgical resection by means of a voltage pulse generator currently used in clinical practice for electrochemotherapy that uses reversible electroporation. The voltage pulses were applied by means of a standard hexagonal electrode composed by seven, 20-mm-long equispaced needles. Irrespective of tumor size, the electrode applies electric pulses to the same volume of tissue. The resistance value was computed from the voltage and current recorded by the pulse generator, and it was correlated with the histological characteristics of the tumor tissue which was assessed by a dedicated pathologist. Some differences in resistance values, which could be correlated to a difference in tissue resistivity, were noticed according to sarcoma histotype. Lipomatous tumors (i.e., those rich in adipose tissue) displayed the highest resistance values (up to 1700 Ω), whereas in the other soft tissue sarcomas, such as those originating from muscle, nerve sheath, or fibrous tissue, the electrical resistance measured was between 40 and 110 Ω. A variability in resistance was found also within the same histotype. Among lipomatous tumors, the presence of myxoid tissue between adipocytes reduced the electrical resistance (e.g., 50-100 Ω). This work represents the first step in order to explore the difference in tissue electrical properties of STS. These results may be used to verify whether tuning electric field intensity according to the specific STS histotype could improve tissue electroporation and ultimately treatment efficacy.

Metastatic malignant soft tissue myoepithelioma: a case report showing complete response after locoregional and systemic therapy.

We report on the case of a 61-year-old man with a soft tissue malignant myoepithelioma of the second toe of the right foot. After removal of the primary tumor, the patient developed in-transit metastases of the limb that we later treated with limb perfusion, using extracorporeal circulation with complete response. Following the appearance of lymph node metastases, the patient underwent inguinal, iliac and obturator lymphadenectomy. Subsequent pelvis metastases were treated with chemotherapy and radiotherapy, with complete response. Currently, after 3 years, the patient is alive and no evidence of any residual disease is apparent.

[Choroid plexus tumours: cytogenetic analysis of a single case and literature review]. / Papilloma dei plessi corioidei: analisi citogenetica di un caso e revisione della letteratura.

Choroid plexus tumours are intraventricular papillary lesions that are observed in typical papillomas, atypical papillomas and carcinomas. They usually occur in childhood, and can result in hydrocephalus and increased intracranial pressure. The present paper describes a case of choroid plexus papilloma in an adult woman; cytogenetic analysis of the lesion is also presented, which demonstrated the presence of tumour mosaicism. Compared to the chromosomal aberrations observed in previous cases, those in the present tumour do not show significant differences between papillomas harboured in adults and paediatric patients. Moreover, there was no apparent correlation between genetic alternations in typical and atypical papillomas and prognosis or recurrence.