Immunoprofile of Inflammatory Myofibroblastic Tumor and Its Mimics Variable Inflammatory Sarcomatoid Myofibroblastic Carcinoma Tumor Cytokeratin cocktail
Positive (>50%) Positive (>90%) LMW cytokeratin Positive Positive HMW cytokeratin Negative Positive (25%-30%) p63 Negative Positive (>50%) Smooth muscle actin Positive (90%) Negative/positive (50% typically focal staining) Desmin Positive/negative Negative (50%) ALK-1 Positive (50%) Negative Variable Leiomyosarcoma Cytokeratin cocktail
Negative (10% aberrant) LMW cytokeratin Positive HMW cytokeratin Negative p63 Negative Smooth muscle actin Positive Desmin Positive ALK-1 Negative (<5% positive) Abbreviations: ALK, anaplastic lymphoma kinase;HMW, high-molecular-weight;LMW, low-molecular-weight.
In cases stained with cytokeratin cocktail
, we found strong diffuse membrane and cytoplasmic staining in most surface cells; 2 of these showed no round cell staining and 1 showed focal weak cytoplasmic round cell staining.
To support the diagnosis of metaplastic carcinoma, we performed an immunohistochemical stain panel, which showed that the spindle cell results were positive for CK903, MNF116, and p63 and negative for a cytokeratin cocktail
(CK AE1/AE3 and CAM 5.
These cases were all reviewed and studied using a cytokeratin cocktail
The clear cells revealed strong S100 expression, and cytokeratin cocktail staining confirmed a ductular pattern for this case, consistent with EMEC.
With respect to EMEC, a bimodal cell population with a ductal pattern was confirmed by cytokeratin cocktail immunohistochemistry.
The following antibodies and dilutions were used: cytokeratin cocktail
(1:800; Dako Corporation, Carpinteria, Calif), S100 (1:800; Enzo Diagnostics Inc, Farmingdale, NY), HMB-45 (1:50; Dako), CD34 (1:200; Becton-Dickinson, Mountain View, Calif), factor VIII (1: 3200; Dako), chromogranin (1:800; Enzo), vimentin (1:80; Dako), and muscle actin (1:1; Ventana Medical Systems Inc, Tucson, Ariz).
Immunohistochemistry was performed in this case for antibodies to S100, smooth muscle actin, muscle-specific actin, desmin, cytokeratin cocktail
, and vimentin, with only vimentin displaying positive reactivity.
Sections were stained with the following primary antibodies: cytokeratin cocktail
(wide-molecular-weight range, CK22, Biomeda, Foster City, Calif; prediluted 1:6), low-molecular-weight cytokeratin (CAM5.
Antibodies used were low-molecular-weight anti-human cytokeratin cocktail
BA17/MNF116 (Dako Corporation, Carpinteria, Calif), high-molecular-weight anti-human cytokeratin 35BH11 (Dako), and anti-vimentin clone Vim 3B4 (Dako).
Tissue sections were incubated with antibodies for cytokeratin cocktail
(AE1/ AE, 1124-161, Boehringer-Mannheim, Indianapolis, Ind, 1:1000; MAK-6, 92-0005, Becton-Dickinson, San Jose, Calif, 1:20; CAM 5.
The antibodies used included cytokeratin cocktail
(AE1/AE3, Boehringer Mannheim, Indianapolis, Ind, 1:1000; CAM 5.