FINAL DIGNOSIS: Metaplastic carcinoma of the breast, spindle cell type. DISCUSSION:
Spindle cell carcinoma of the breast (SpCC) is a rare variant of metaplastic carcinoma in which the spindle cell component predominates; it presents as a wide spectrum of findings with mildly atypical features resembling a reactive process such as fasciitis, fibromatosis or granulation tissue reaction or with more malignant features resembling a low-grade sarcoma. The largest series of SpCC of the breast to date was reported in 1989 by Wargotz et al. (1) and defined as an intraductal or infiltrating carcinoma (ductal, lobular, squamous or mixed) that is contiguous or subtly merges with a blend, monotonous-appearing spindle cell proliferation that comprises more than half of the neoplasm.
SpCC is mainly diagnosed in postmenopausal women with the average age of 63, but it can be present between ages 29 and 95. The clinical presentation is that of a single, palpable, firm breast mass, located most often in the upper outer quadrant. The tumor is painless and, in the majority of the cases, presents without axillary enlargement.
On gross examination the tumors are firm to hard, well circumscribed or ill defined and could measure from less then 1 cm to over 20 cm. They are pink-tan and frequently mottled, with one or more cysts.
Microscopically, the main features include the presence of two distinctive components that are necessary for the diagnosis (1):
Benign tumors: when the presence of an overt carcinoma is ruled out by thorough sampling of the lesion, several very rare lesions of the breast should be considered
The cumulative 5-year survival for SpCC is 64% (1) and is higher survival rate as compared to the metaplastic carcinoma overall.
SpCC tends to recur in approximately 56% of the case (1), both as local recurrences or metastasis. The recurrence rate depends on the initial treatment, as well as the gross and microscopic tumor characteristics, with tumor size and microscopic circumscription showing significant difference (1)(Table 2). Table 2 (from Wargotz et al.) The pathologic features of SpCC in recurrent an non-recurrent neoplasms
|Size||3.7 cm||5.0 cm|
Contributed by Diana Ionescu, MD and Mirka W Jones, MD