Solid variant of mammary adenoid cystic carcinoma with basaloid features: a clinicopathologic and immunohistochemical study / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinicopathologic and immunohistochemical features as well as the differential diagnoses of the solid variant of mammary adenoid cystic carcinoma with basaloid features.</p><p><b>METHODS</b>Clinical and pathological data were collected in four cases of the solid variant of mammary adenoid cystic carcinoma with basaloid features, and microscopic pathological examination and immunohistochemistry EnVision method were performed. The relevant literature was also reviewed.</p><p><b>RESULTS</b>The four patients were female, with age ranged from 46 - 65 years old (average 56 years) and the maximum tumor diameter ranged from 1.5 to 2.5 cm. Microscopically, the tumors exhibited a predominantly solid architecture with a myxoid or hyalinized stroma. The tumor cells showed moderate to marked nuclear atypia, and a basaloid appearance with scanty cytoplasm and inconspicuous nucleoli, and ≥ 5 mitotic figures per 10 high power fields. Glandular space embedded within tumor islands could be noticed. These spaces were genuine glandular structures and the cells lining these true glandular lumens had more abundant and eosinophilic cytoplasm. Pseudoglandular spaces of cribriform pattern or variable shape were also occasionally seen, and these cysts contained homogenous eosinophilic material. Focal necrosis was found. All cases were negative for ER, PR and HER2. Immunohistochemical staining for CK5/6, CK7 and CK14 was positive in the genuine glandular structures. All cases were positive for CD10, but also positive with varying intensity from weak to strong for vimentin and CD117. Staining for Ki-67 in three patients showed 10% - 50% positive.</p><p><b>CONCLUSIONS</b>The solid variant of mammary adenoid cystic carcinoma with basaloid features is a histologically distinctive and also a rare subset of the mammary adenoid cystic carcinoma. Awareness of its pathological features can help with the diagnosis as well as differential diagnosis. More cases are still needed for accurately assessing the prognosis of this particular tumor.</p>

Rhabdomyosarcoma of the breast: a clinicopathologic study and review of the literature / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Rhabdomyosarcoma (RMS) is an uncommon malignancy of the breast. The aim of this study was to summarize its clinicopathologic features and biological behavior.</p><p><b>METHODS</b>Five primary or secondary breast RMSs were collected. Their clinicopathological characteristics and all published literature about breast RMS were reviewed. Immunohistochemical study of desmin, myogenic differentiation 1 (MyoD1), myogenin, leukocyte common antigen (LCA), vimentin, cytokeratin (AE1/AE3), E-cadherin, neuron specific enolase (NSE), CD99, chorioallantoic membrane 5.2 (CAM5.2) and epithelial membrane antigen (EMA) expression were performed.</p><p><b>RESULTS</b>The five patients were all female with ages ranging from 16 to 46 years old (mean, 30 years). Three were metastatic breast RMSs, two embryonal and one solid variant alveolar, with the primary tumor sites the right labium majus, left nasal meatus and nasopharynx, respectively. The other two, one embryonal and one alveolar, were primaries. Grossly, the surgical specimens revealed round or oval, well-demarcated but nonencapsulated masses. Their cut surfaces consisted of homogeneous grayish yellow or white tissue. Microscopically, most tumor cells were poorly differentiated small round, oval or small polygons with eosinophilic cytoplasm. All cases were positive for vimentin, desmin, MyoD1 and myogenin. One embryonal RMS also had a few cells with perinuclear staining of AE1/AE3. The other markers were negative.</p><p><b>CONCLUSIONS</b>Although primary or metastatic RMS in breast was almost confined to young adolescent females, our cases suggested that it can also happen to the middle-aged women. Embryonal RMS has a certain metastatic potential. MyoD1 and myogenin are two useful markers when making differential diagnosis. Axillary lymph node status and age may play a role in the prognosis of primary breast RMS patients.</p>