Malignant Schwannoma Arising in Patients with Von Recklinghausen's Disease: Report of Two Cases and the Comparison of Mast Cells between Benign and Malignant Portions

Abstract

We described two cases of malignant schwannoma arising in patients with von Recklinghausen's disease and examined the mast cells infiltrated into histologic sections. One of the two cases histologically revealed apparent mast cell infiltration in some areas of malignant schwannoma as well as in the benign neurofibroma. The malignant lesion demonstrated significantly increased percentages of degranulated mast cells over the benign lesion using FITC-avidin staining. In an electron microscopic study, mast cells in the malignant lesion displayed empty granules, piecemeal degranulation, and canaliculi structures suggesting activation. These findings were not observed in the benign lesion. The other patient histologically showed no mast cells in the malignant lesion, although the benign neurofibroma in the patient disclosed numerous mast cells. The first patient had neither recurrence nor distant metastasis. On the other hand, the second patient without mast cells in the histology had multiple distant metastases.

Potential use of embalmed cadavers to study mast cell presence

“…Taking advantage of that allows the researcher to stain the granules as an indication of mast cell presence and whether or not the mast cell is in the process of lysis or degranulation. Use of FITC-Avidin has become a common technique to study mast cells (Demitsu et al, 1995) even though other fluorescent techniques (Espada et al, 1995), and more exotic antibody techniques (Willheim et al, 1995) now exist. This technique is currently being used to study the presence of mast cells in preclinical and undiagnosed Peyronie's disease (PD), which is a fibrotic scarring of the tunica albuginea surrounding the corpora cavernosa of the penis.…”

Activation of Mast Cells within a Tumor of Angiosarcoma: Ultrastructural Study of Five Cases

“…The functional significance of mast cells in cancer is controversial because of contradictory findings. A correlation between increased mast cell number and low histologic grade of malignancy or favorable prognosis has been reported for several tumors such as breast cancer (1), uterine cervical cancer (2), lung cancer (3), rectal cancer (4) or soft tissue sarcomas (5–7), suggesting a role for mast cells in tumor suppression. In contrast, other studies have shown that an increased mast cell number correlated with a high histologic grade of malignancy in cervical carcinoma (8), breast cancer (9), and melanoma (10).…”