Immunohistochemical stains were performed and the neoplastic cells were negative for cytokeratin AE1/AE3, cytokeratin cocktail
, synaptophysin, chromogranin, p63, thyroid transcription factor 1 (TTF-1), leukocyte common antigen, and other lymphoid markers while they were diffusely positive for CD56.
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 5.2) (Figure 2, a through e).
These cases were all reviewed and studied using a cytokeratin cocktail
(CAM 5.2 and AE1/AE3) and epithelial membrane antigen using standard immunohistochemical techniques.
The clear cells revealed strong S100 expression, and cytokeratin cocktail
staining confirmed a ductular pattern for this case, consistent with EMEC.
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.
In contrast to the surrounding keratinocytes, the pagetoid cells stained intensely for the cytokeratin cocktail
CK22 (Figure 3) and for 34[Beta]E12 (Figure 4).
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 5.2, 28-0001, Zymed, San Francisco, Calif, 1:100); vimentin (M0725, Dako, 1:50); desmin (M0724, Dako, 1:15); [Alpha]-smooth muscle actin (A2547, Dako, 1:75); muscle actin (HHF-35) (C34931, Enzo Diagnostics Inc, New York, NY, 1:20 000); smooth muscle myosin-heavy chain (M3558, Sigma, St Louis, Mo, 1:1000); CD34 (M236UC, Immunotech, Marseille, France, 1:75); CD99 (O13) (8810, Signet, Dedham, Mass, 1:30); S100 (20311, Dako, 1:3000); and Bcl-2 (M0887, Dako, 1:5) using the avidin-biotin peroxidase complex technique.
The antibodies used included cytokeratin cocktail
(AE1/AE3, Boehringer Mannheim, Indianapolis, Ind, 1:1000; CAM 5.2, Becton-Dickinson, San Jose, Calif, 1:100; Mak-6, Zymed, South San Francisco, Calif 1:20); S100 protein (Dako Corporation, Carpinteria, Calif, 1:3000); vimentin (BioGenex, San Ramon, Calif, 1: 80); muscle-specific actin (HHF-35, Enzo, New York, NY, 1: 32000); smooth muscle actin (SMA, Sigma, St Louis, Mo, 1: 3000); chromogranin (Dako, 1:5); synaptophysin (Dako, 1:100); monoclonal carcinoembryonic antigen (mCEA, BioGenex, 1: 100); prostate-specific antigen (PSA, Dako, 1:2000); CD31 (Dako, 1:5); and factor VIII (Dako, 1:200).