Malignant Transformation of Mastocytoma Developed on Skin Mastocytosis Into Cutaneous Mast Cell Sarcoma

Abstract

Mastocytosis is a group of disorders characterized by abnormal mast cell proliferation, involving the skin in 80% of cases. Cutaneous mastocytosis, which appears in childhood in 60% of cases, usually has a benign course with a gradually regressive evolution before puberty. Mast cell sarcomas, part of the systemic forms of mastocytosis, are very rare tumors characterized by a destructive growth of highly atypical mast cells, with secondary spread, poor prognosis, and low survival rates. We report the first known case of primary cutaneous mast cell sarcoma due to the transformation of a benign solitary mastocytoma in an adult suffering from an unregressive localized cutaneous mastocytosis. Histologic characteristics of the tumor, mutation analysis, and c-Kit expression were compared with available data. Wide surgical excision of the tumor followed by adjuvant local radiotherapy were performed, and for the first time the use of imatinib was attempted, as neoplastic mast cells expressed the CD117 marker. However, they failed to control the progression of sarcoma. To date, no treatment is known to be effective for this disease, which is associated with short-term survival of the patients.

Mast cell sarcoma: a rare and potentially under-recognized diagnostic entity with specific therapeutic implications

“…Our case 2 is of particular interest in that the tumor occurred in a patient who had recovered from infantile cutaneous mastocytosis 17 years previously, and apparently arose in a residual lesion of urticaria pigmentosa in the mucosa of the lip, a clinical evolution similar to that of the case recently reported by Auquit-Auckbur et al 9 Interestingly, case 2 showed urticaria pigmentosa and mast cell sarcoma in two different regions of the same biopsy. These two cases appear to represent malignant transformation of a previously quiescent mast cell clone, implying that at least some cases of mast cell sarcoma may be biologically more closely related to pediatric cutaneous mastocytosis than to adult systemic mastocytosis.…”

“…However, the characteristic longitudinal nuclear grooves of Langerhans cell histiocytosis were not seen in our mast cell sarcoma cases, and essentially all cases of Langerhans cell histiocytosis should show immunohistochemical expression of S100, CD1a, and langerin. The well- Auquit-Auckbur et al 9 Bugalia et al 7 Ma et al 8 Brcic et al 6 Guenther et al, 22 Chott et al 5 Kojima et al 4 Auquit-Auckbur et al 9 Bugalia et al 7 Ma et al 8 Brcic et al 6 Guenther et al, 22 Chott et al 5 Kojima et al 4 14 and should prompt consideration of other diagnoses. Variable KIT expression may occasionally be seen in T cell lymphomas, but the uniformly strong expression seen in two of our three mast cell sarcoma cases would be highly unusual, and expression of CD68 should not be seen.…”

“…Although relatively common in dogs, 2 mast cell sarcoma, defined as a malignant mast cell neoplasm presenting as an isolated destructive mass, is exceedingly rare in humans. 1 As only seven cases of mast cell sarcoma have been reported to date in the English language literature, [3][4][5][6][7][8][9] each representing a single case report, there is limited information available regarding the diagnostic features, clinical behavior, and genetic aberrations associated with this entity.…”

Mast Cell Activation Syndrome

“…Mast cell sarcomas, part of the systemic forms of mastocytosis, are very rare tumors characterized by a destructive growth of highly atypical mast cells, with secondary spread, poor prognosis, and low survival rates [18]. Falleti reported the first known case of primary cutaneous mast cell sarcoma due to the transformation of a benign solitary mastocytoma in an adult suffering from an unregressive localized cutaneous mastocytosis [19].…”

Mastocytosis. Review of the literature and description of clinical cases

“…Туч-ноклеточная саркома встречается в матке [11], кишечнике [12], костях [13] и коже [14] и, как правило, имеет деструктивный рост. Внекожная мастоцитома может быть с вовлечением легочной ткани и характеризуется неинвазивным ростом опухоли [3].…”