A Red-Brown Plaque on the Nape—Quiz Case

Case report of a clinically indolent but morphologically high‐grade cutaneous mast cell tumor in an adult: Atypical cutaneous mastocytoma or mast cell sarcoma?

“…Of the 14 cases in the literature with adult mastocytomas, eight had a surgical resection. 4 , 5 , 7 , 10 , 11 , 13 , 14 , 15 In six of these eight cases, follow‐up data were available, with durations between 7 months and several years, without reported recurrence. 4 , 5 , 7 , 10 , 11 , 13 , 14 , 15 The recurrence in our case may be explained by small foci of mast cells in the resection margins.…”

“… 4 , 5 , 7 , 10 , 11 , 13 , 14 , 15 In six of these eight cases, follow‐up data were available, with durations between 7 months and several years, without reported recurrence. 4 , 5 , 7 , 10 , 11 , 13 , 14 , 15 The recurrence in our case may be explained by small foci of mast cells in the resection margins. Although the WHO classification 1 states that atypia should be absent in mastocytoma, several case reports 7 , 17 , 18 , 19 , 20 , 21 showed that type II atypia of mast cells can occur in mast cell tumors with benign behavior.…”

“…7,17 Although histomorphology raised concern about a malignant behavior, none of these patients showed systemic involvement or destructive growth, and after excision no recurrence was observed. [4][5][6][7][8][9][10][11][12][13][14][15] Here, we report on an atypical solitary mast cell tumor in a middle-aged patient, which in contrast to the other described cases recurred after excision, showed progressive cytological pleomorphism and an unusually high proliferation rate, but did not show any signs of clinical malignancy after more than 6 years of follow-up.…”

“…3 In the literature, only 14 cases of adult purely cutaneous mastocytomas have been reported. [4][5][6][7][8][9][10][11][12][13][14][15] In cutaneous mastocytosis and indolent systemic mastocytosis, mast cells have round or oval nuclei and abundant metachromatic cytoplasm, 1 or are spindle-shaped hypogranulated cells being referred as atypical mast cells type I. 1,16 A third type of cytomorphology consists of mast cells with nuclear pleomorphism, including bilobation and/or multilobation; these cells are known as atypical mast cell type II or promastocytes.…”

Case Report: Solitary mastocytoma treated successfully with topical tacrolimus

“…The lesion turns edematous and itchy on manipulation [rubbing or trauma to the lesion]. Mild tenderness and the formation of vesicles or bulla can also occur 4 . These features can sometimes be so mild that they may not come to the attention of parents.…”