AIMS: Reports on the frequency of myoepithelial loss in solid papillary carcinoma (SPC) of the breast, an unusual variant of papillary carcinoma with a solid pattern of expansile growth, have been strikingly contradictory. The aim was to clarify the frequency of myoepithelial loss in cases of SPC diagnosed at our institution. METHODS AND RESULTS: Eleven cases of SPC with available blocks or unstained slides were retrieved from the M. D. Anderson archives or obtained from outside contributors. Immunohistochemistry for smooth muscle actin (SMA) and p63 was evaluated on the circumscribed nests that appeared to be non-invasive by haematoxylin and eosin morphology. Three of the 11 cases (27%) were positive for both SMA and p63 at the periphery of all such foci, whereas eight cases (73%) lacked staining for both myoepithelial markers in at least one focus. Of these eight cases, one was diagnosed with only microinvasion, yet metastatic tumour resembling the circumscribed primary SPC was identified in two ipsilateral axillary lymph nodes. CONCLUSIONS: SPC of the breast frequently lacks myoepithelial markers at the tumour-stromal interface in spite of a circumscribed non-invasive appearance. Metastases from such tumours are infrequent, but can occur in cases that lack myoepithelial marker expression by immunohistochemistry.
AIMS: Reports on the frequency of myoepithelial loss in solid papillary carcinoma (SPC) of the breast, an unusual variant of papillary carcinoma with a solid pattern of expansile growth, have been strikingly contradictory. The aim was to clarify the frequency of myoepithelial loss in cases of SPC diagnosed at our institution. METHODS AND RESULTS: Eleven cases of SPC with available blocks or unstained slides were retrieved from the M. D. Anderson archives or obtained from outside contributors. Immunohistochemistry for smooth muscle actin (SMA) and p63 was evaluated on the circumscribed nests that appeared to be non-invasive by haematoxylin and eosin morphology. Three of the 11 cases (27%) were positive for both SMA and p63 at the periphery of all such foci, whereas eight cases (73%) lacked staining for both myoepithelial markers in at least one focus. Of these eight cases, one was diagnosed with only microinvasion, yet metastatic tumour resembling the circumscribed primary SPC was identified in two ipsilateral axillary lymph nodes. CONCLUSIONS: SPC of the breast frequently lacks myoepithelial markers at the tumour-stromal interface in spite of a circumscribed non-invasive appearance. Metastases from such tumours are infrequent, but can occur in cases that lack myoepithelial marker expression by immunohistochemistry.
Authors: Sumanta Kumar Pal; Sean K Lau; Laura Kruper; Uzoamaka Nwoye; Carlos Garberoglio; Ravi K Gupta; Benjamin Paz; Lalit Vora; Eduardo Guzman; Avo Artinyan; George Somlo Journal: Breast Cancer Res Treat Date: 2010-06-04 Impact factor: 4.872
Authors: Meghana Agni; Meisha L Raven; Randy C Bowen; Nora V Laver; Patricia Chevez-Barrios; Tatyana Milman; Charles G Eberhart; Steven Couch; Daniel D Bennett; Daniel M Albert; R Nick Hogan; Paul O Phelps; Hillary Stiefel; Norberto Mancera; Martin Hyrcza; Ami Wang; Christopher K H Burris; Eric A Steele; Ashley A Campbell; Heather D Potter; Mark J Lucarelli Journal: Am J Surg Pathol Date: 2020-08 Impact factor: 6.298