Poorly differentiated squamous cell carcinoma of the nipple: a unique case for marked exophytic growth, but little invasion with neuroendocrine differentiation

Abstract

A 73-year-old woman showed marked exophytic growth of a tumor (25 × 23 × 14 mm) of the nipple over a period of 2 months. Histologically, numerous tumor nodules with no apparent keratinization were observed in the exophytic lesion. The tumor cells also showed little invasion to the dermis and no metastasis to the axillary lymph nodes (LN). The tumor cells were immunohistochemically positive for cytokeratins (CKs; AE1/AE3 and 34βE12), epithelial membrane antigen (EMA), and p53, but negative for Ber-EP4 and human papilloma virus (HPV). The MIB-1 index was 56%. Some tumor cells were also positive for some neuroendocrine markers, and showed some tonofilaments and neurosecretory granules in the cytoplasm under electron microscopy. We made the differential diagnosis of mammary ductal carcinoma, basal cell carcinoma (BCC), Paget's disease, and neuroendocrine carcinoma including Merkel cell carcinoma. The final diagnosis was poorly differentiated squamous cell carcinoma (SCC) showing exophytic growth with neuroendocrine differentiation (ND) in the nipple. To our knowledge, although only five cases of Bowen's disease have been reported in the nipple, such a unique SCC has not been reported previously.

Primary squamous neuroendocrine carcinoma of the skin: A case report with immunohistochemical study

“…The present case is very similar to the cases of Hosaka et al, [10] Dadzie et al, [12] and Isimbaldi et al. [8] Their cases also showed squamoid features on HE sections; however, immunohistochemical and electron microscopic investigations of their cases showed neuroendocrine features.…”

“…[4][5][6][7] Primary cutaneous NEC has been reported as cutaneous NEC in 6 cases, [8][9][10][11][12][13] to the best of the author's knowledge. Thus, primary cutaneous NET and NEC except for MCC are exceptionally rare.…”

A common cancer in an uncommon location: A case report of squamous cell carcinoma of the nipple

“…The current literature exhibited a wide range of approaches in treatment but as in cutaneous SCC, a wide local excision has been the primary choice but mastectomy and photodynamic therapy was also reported [3], [4], [5], [6], [7], [8], [9], [10], [11]. Of the cases only two reported local reoccurrence, one of the cases was treated via an incomplete local resection that was corrected with repeat resection and the other case was initially treated with a photosensitizer and retreated with cryotherapy [3], [4], [5], [6], [7], [8], [9], [10], [11]. Of the cases with no reported reoccurrence, patients were SCC free for six months up to five years as reported in one of the cases with mastectomy [5], [9].…”

“…Of the cases only two reported local reoccurrence, one of the cases was treated via an incomplete local resection that was corrected with repeat resection and the other case was initially treated with a photosensitizer and retreated with cryotherapy [3], [4], [5], [6], [7], [8], [9], [10], [11]. Of the cases with no reported reoccurrence, patients were SCC free for six months up to five years as reported in one of the cases with mastectomy [5], [9].…”

“…SCC specifically is the second most prevalent of the two [2]. However it is rarely seen on the nipple as can be seen in the limited number of case reports seen in literature which at last count was ten cases [3], [4], [5], [6], [7], [8], [9], [10], [11]. Paget’s disease of the breast (PDB) on the other hand while rare itself is the most common malignancy of the nipple areola complex [12].…”