Robin H Amirkhan

University of Texas Southwestern Medical Center, Dallas, TX, United States

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Publications (17)39.75 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Overexpression of excision repair cross complementing group 1 (ERCC1), a DNA repair enzyme, is associated with resistance to cisplatin. Tissues from 73 patients with squamous cell carcinoma of the head and neck (HNSCC) who received concurrent cisplatin and radiation was analyzed immunohistochemically to determine if ERCC1 expression predicted for survival and response. Expression was scored as follows: 0=0% tumor nuclei positive, 1+=<50%, 2+=50-75% and 3+=>75%. ERCC1 expression was 0 in 0%, 1+ (14%), 2+ (42%) and 3+ (44%). In uni- and multivariate analyses, 3+ ERCC1 expression was not a significant predictor of survival or response. Median survival for the ERCC1 3+ patients was 2.9 years versus 2.1 years for the ERCC1 <3+ group (p=0.44). In this retrospective review of HNSCC patients receiving concurrent cisplatin and radiation, ERCC1 expression was not a significant predictor of survival or response.
    Anticancer research 12/2011; 31(12):4135-9. · 1.87 Impact Factor
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    ABSTRACT: Granular cell tumors (GCTs) are classified as benign when none of the following features is present: spindling of the tumor cells, necrosis, diffuse pleomorphism, prominent nucleoli, high nuclear-cytoplasmic ratio, and mitotic rate >2 per 10 high-power fields. It has been suggested that a GCT be classified as atypical when 1 or 2 of these features are seen and as malignant when 3 or more of these are present. In our practice, we do not classify GCTs as malignant in the absence of metastasis. To compare immunohistochemical staining for phosphorylated histone H3 (PHH3), Ki-67 (MIB-1), p21, fatty acid synthase, and cleaved caspase-3 in histologically classified benign and atypical GCTs. We reviewed 25 cases of GCT from our archives and classified 14 as atypical based on histologic features. Immunohistochemical staining for PHH3, Ki-67, p21, fatty acid synthase, and cleaved caspase-3 was performed using standard methods. The number of positive cells for Ki-67, p21, and PHH3 was calculated in 10 consecutive high-power fields in a hot spot. Fatty acid synthase and cleaved caspase-3 cytoplasmic expression was graded from 1 to 3. Ki-67 and PHH3 scores were significantly higher in atypical GCTs. The expression of p21, fatty acid synthase, and cleaved caspase-3 was not significantly different between atypical and benign GCTs. This study shows that histologic features are reliable in identifying GCTs that have a higher proliferative potential as shown by higher immunoreactivity for Ki-67 and PHH3. These immunostains may help in classifying GCTs in cases where a thorough histologic evaluation is precluded by the small size of a biopsy specimen.
    Archives of pathology & laboratory medicine 02/2007; 131(1):57-64. DOI:10.1043/1543-2165(2007)131[57:PHHKPF]2.0.CO;2 · 2.88 Impact Factor
  • Payal Kapur, Dinesh Rakheja, Robin H. Amirkhan
    Laboratory Medicine 09/2006; 37(9):533-535. DOI:10.1309/2MRN-JUF9-FPD6-G61X · 0.49 Impact Factor
  • Wen S. Lai, Robin H. Amirkhan, Sanjay G. Revankar
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    ABSTRACT: Zygomycosis, in particular, infection due to fungi of the order Mucorales, is typically found in patients with diabetes, solid organ transplants, hematologic malignancies, or those treated with deferoxamine. Recently, with increased myleosuppressive chemotherapy regimens, more cases of pulmonary or disseminated zygomycosis have been reported in neutropenic patients than in the past. We present a white man diagnosed with gastric adenocarcinoma who presented with a small bowel perforation due to gastrointestinal zygomycosis. He was not significantly neutropenic, however, his risk for development of this unusual fungal infection was malnutrition, acidosis, and leukopenia.
    Infectious Disease in Clinical Practice 08/2005; 13(5):271-273. DOI:10.1097/01.idc.0000168471.58223.95
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    ABSTRACT: Preclinical data suggests that VEGF and COX-2 are potentially important mediators in the pathogenesis of small cell lung cancer (SCLC). Little is known about the frequency of tumor expression of VEGF and COX-2 in SCLC or the prognostic significance of this expression. Clinical records from 54 cases of SCLC were reviewed. Immunohistochemical stains for VEGF and COX-2 were performed on all tumor specimens. Tumor VEGF expression was detected in 43 cases (81%) and COX-2 expression in 11 (20%). No significant association between VEGF or COX-2 expression and survival was observed. This is the first study to assess the frequency and clinical significance of tumor VEGF and COX-2 expression in a large group of patients with SCLC. In this cohort, neither VEGF nor COX-2 expression impacted survival. The frequency of VEGF expression suggests that it merits further investigation as a therapeutic target in SCLC.
    Anticancer research 07/2004; 24(4):2367-73. · 1.87 Impact Factor
  • Jared J Abbott, Robin H Amirkhan, Mai P Hoang
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    ABSTRACT: Malignant melanoma is known to display tremendous histologic diversity. One rare variant is the rhabdoid phenotype, so called because of the appearance of cells resembling rhabdomyoblasts seen in malignant rhabdoid tumors of the kidney. We present the histologic, immunohistochemical, and ultrastructural features of a malignant melanoma composed entirely of rhabdoid cells. A 62-year-old man presented with a 6.5-cm lung mass. Although presumed to be a metastatic lesion, extensive workup failed to reveal a primary tumor site. Histologic sections showed a mass composed entirely of polygonal neoplastic cells with prominent nucleoli and large hyaline cytoplasmic inclusions. The tumor cells were strongly immunoreactive with S100 protein, vimentin, and CD56, and were focally reactive with Mart-1. Tumor cells were negative for Melan-A, tyrosinase, HMB-45, AE1/AE3, cytokeratin (CK) 7, CK8/ 18, CK20, CK903, CAM 5.2, epithelial membrane antigen, smooth muscle actin, desmin, leukocyte common antigen, Bcl-2, CD3, CD20, CD30, CD138, kappa and lambda light chains, CD68, CD34, factor VIII, synaptophysin, and glial fibrillary acidic protein. Electron microscopy showed cytoplasmic whorls of intermediate filaments containing entrapped rough endoplasmic reticulum, mitochondria, and lipid. Recognition of this rare variant of malignant melanoma is important in the evaluation of tumors with rhabdoid morphology.
    Archives of pathology & laboratory medicine 07/2004; 128(6):686-8. DOI:10.1043/1543-2165(2004)128<686:MMWARP>2.0.CO;2 · 2.88 Impact Factor
  • Vilkesh R Jaiswal, Robin H Amirkhan, Mai P Hoang
    Archives of pathology & laboratory medicine 01/2004; 127(12):e432-3. · 2.88 Impact Factor
  • Mai P Hoang, Robin H Amirkhan
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    ABSTRACT: Inhibin alpha subunit (inhibin A) expression in hemangioblastomas has not been previously reported in the literature. We analyzed the expression of inhibin A in 25 hemangioblastomas from 22 patients. Eleven cases were from 8 patients with von Hippel-Lindau disease, and these tumors were multicentric and/or recurrent. The remaining 14 cases from 14 patients were sporadic. The male-to-female ratio was 8:3, and the age at presentation ranged from 19 to 78 years (mean 35 years; median 45 years). Eighteen tumors were located in the cerebellum/posterior fossa, 1 in the medulla, 1 in the occipital lobe, and 5 in the spinal cord. Four metastatic renal cell carcinomas in brain, 10 renal cell carcinomas from 8 patients with von Hippel-Lindau disease, and 5 sporadic clear cell renal cell carcinomas were also included. Two patients with von Hippel-Lindau disease had both renal cell carcinoma and hemangioblastoma. The stromal cells of all 25 cases of hemangioblastoma expressed inhibin A. Strong, moderate, and weak cytoplasmic immunoreactivity was noted in 17, 5, and 3 cases, respectively. In contrast, none of the 19 renal cell carcinomas, primary as well as metastatic, expressed inhibin A. There was no difference in the inhibin A staining pattern between the sporadic hemangioblastoma and those associated with VHL. These findings demonstrate inhibin A to be a useful marker in distinguishing hemangioblastoma from metastatic clear cell renal cell carcinoma. While the diagnostic importance is evident, the pathophysiology of inhibin A expression by the stromal cells of hemangioblastoma remains unknown and further investigation is required.
    American Journal of Surgical Pathology 09/2003; 27(8):1152-6. DOI:10.1097/00000478-200308000-00014 · 4.59 Impact Factor
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    ABSTRACT: Cystic sebaceous neoplasms have been seen only in patients with Muir-Torre syndrome (MTS) and have recently been characterized as marker lesions of MTS. Histologically, these lesions form a spectrum of tumors ranging from benign cystic adenomas to proliferative cystic sebaceous tumors. We describe 2 proliferative cystic sebaceous tumors in a 53-year-old man whose workup revealed colonic adenocarcinoma and other sebaceous tumors consistent with MTS. Both the chest wall and the left thigh masses were grossly cystic, measuring 1.0 and 1.5 cm, respectively. Histologic sections demonstrated well-circumscribed cystic neoplasms located in the deep dermis and subcutaneous tissue. Each had a focally infolded cyst wall composed of immature basaloid cells with prominent nucleoli and mitoses, consistent with a proliferative cystic sebaceous tumor. Recognition of cystic sebaceous neoplasm by pathologists and communication to clinicians of its strong association with MTS is of diagnostic importance.
    Archives of pathology & laboratory medicine 06/2003; 127(5):614-7. DOI:10.1043/0003-9985(2003)127<0614:CSNIMS>2.0.CO;2 · 2.88 Impact Factor
  • Mai P Hoang, Dinesh Rakheja, Robin H Amirkhan
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    ABSTRACT: Rosette formation is a feature that has not been described as occurring in melanocytic neoplasms. We present such a unique case. A 59-year-old man presented with an asymptomatic, soft, hairy 3.0 x 2.0-cm pigmented lesion that had been present for many years in the right external ear, extending from the conchal bowl onto the antitragus area. Examination of histologic sections showed a proliferation of nonatypical and heavily pigmented melanocytes in the superficial dermis and around deep adnexal structures, characteristic of a congenital nevus. In other areas, pigmented spindled and dendritic cells infiltrated thickened collagen bundles in a pattern of a blue nevus. A nodular proliferation of epithelioid melanocytes was seen within the deep dermis and subcutaneous tissue. The periphery of the nodule merged with the surrounding nevus cells. Neoplastic cells with nuclear atypia, melanin pigment, pseudonuclear inclusions, and balloon cell change were present. In addition, there was rosette formation by the tumor cells, with a central aggregate of coarse cell processes. Neuroid cords were also noted. No prominent mitotic figures, necrosis, or significant inflammatory infiltrate were noted. The neoplastic cells were positive for S-100 protein, Mart-1, tyrosinase, neuron-specific enolase, and vimentin. HMB-45 and Ki-67 (MIB-1) labeled only rare neoplastic cells within the proliferative nodule. The tumor cells were negative for synaptophysin, protein gene product 9.5, CD57, epithelial membrane antigen, CD31, and CD34. The central cell processes of the rosettes were negative for trichome, type IV collagen, neurofilament protein, glial fibrillary acidic protein, and tyrosine hydroxylase. We also retrospectively examined 78 congenital nevi of 65 pediatric patients at our institution. Rosette formation was not seen in any of these cases.
    American Journal of Dermatopathology 03/2003; 25(1):35-9. DOI:10.1097/00000372-200302000-00008 · 1.43 Impact Factor
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    ABSTRACT: We compared the effectiveness and safety of image-guided biopsies done with coaxial guides versus fine-needle aspiration done without coaxial guides. With the use of hospital computer records and chart reviews, all image-guided biopsies done during a 4-year period at our institution were assessed for adequacy and complications. For each biopsy, the use of a coaxial guide, the site, and the imaging modality were recorded. Adequacy of the biopsy and complications were compiled. Success rates were calculated for conventional and coaxial biopsies and by modality and site. Coaxial technique reduced the number of unsatisfactory biopsies compared with conventional technique in extrathoracic sites. The decrease was statistically significant. No major complications occurred from extrathoracic biopsies with either technique. No difference was found in success rates or complication rates between ultrasound-guided and CT-guided biopsies using coaxial technique. Coaxial technique reduces the number of inadequate biopsies in extrathoracic sites, without a detectable increase in complications.
    Southern Medical Journal 03/2002; 95(2):212-7. · 1.12 Impact Factor
  • Southern Medical Journal 01/2002; 95(2):212-217. DOI:10.1097/00007611-200295020-00012 · 1.12 Impact Factor
  • Southern Medical Journal 01/2002; 95(2):212-217. DOI:10.1097/00007611-200202000-00011 · 1.12 Impact Factor
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    ABSTRACT: The role of mammography in the evaluation of male patients presenting with breast disease is controversial. This controversy is a function of the lack of specific data concerning the diagnostic accuracy of mammography when used in this clinical setting. The purpose of this study was to define the diagnostic accuracy of mammography in the evaluation of male breast disease. One hundred and four prebiopsy mammograms from 100 patients with tissue diagnoses were read blindly by two independent radiologists, and placed into one of five predetermined categories: definitely malignant, possibly malignant, gynecomastia, benign mass, and normal. Radiologic/pathologic correlation was performed and the sensitivity (Sn), specificity (Sp), positive (Ppv) and negative predictive value (Npv), and accuracy (Ac) for each of the mammographic diagnostic category determined. The pathologic diagnoses were 12 cancers, including 1 patient with bilateral breast cancer, 70 cases of gynecomastia, 16 benign masses, and 6 normals. The accuracy data for the mammographic diagnostic categories are as follows: malignant (combined definitely and possibly malignant), Sn 92%, Sp 90%, Ppv 55%, Npv 99%, Ac 90%; and overall benignity (combined gynecomastia, benign mass, and normal), Sn 90%, Sp 92%, Ppv 99%, Npv 55%, Ac 90%. Six cancers (50%) coexisted with gynecomastia. Mammography can accurately distinguish between malignant and benign male breast disease. Although not a replacement for clinical examination, its routine use could substantially reduce the need for biopsy in patients whose mammograms and clinical examination suggest benign disease.
    The American Journal of Surgery 03/2001; 181(2):96-100. DOI:10.1016/S0002-9610(00)00571-7 · 2.41 Impact Factor
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    ABSTRACT: Bcl-2 overexpression is a common event in small cell carcinomas (SCLC). The bcl-2 oncoprotein has a unique oncogenic role by inhibiting programmed cell death (apoptosis), resulting in tumorigenesis and chemoresistance. Forty-two cases of SCLC were stained immunohistochemically with bcl-2 monoclonal antibody (Biogenex, San Ramon, CA) after using an antigen retrieval step with citrate buffer. bcl-2 positivity was determined as detection of the oncoprotein in greater than 10% of noncrushed neoplastic cells. Twenty-five of 42 (60%) patients had extensive disease at presentation, 10 of 42 (24%) had limited disease, and 7 of 42 (16%) had disease localized to the lung. Twenty-four of 42 (57%) tumors were bcl-2 positive, and 18 of 42 (43%) tumors were bcl-2 negative. Follow-up in patients ranged from 7 days to 96 months (mean follow-up, 20 months). The median survival of patients with bcl-2-positive tumors was 11 months, as opposed to 13 months for bcl-2-negative tumors. There was no significant difference in median survival between bcl-2-positive and bcl-2-negative SCLC (log rank test, P = .2256). Using Cox's proportional hazards model, median survival in SCLC was determined to be independent of age at diagnosis, stage at presentation, therapeutic modality, and bcl-2 expression. bcl-2 expression does not significantly influence survival in SCLC.
    Human Pathlogy 07/1999; 30(6):712-7. DOI:10.1016/S0046-8177(99)90099-0 · 2.81 Impact Factor
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    ABSTRACT: Various male breast diseases have characteristic mammographic appearances that can be correlated with their pathologic diagnoses. Male breast cancer is usually subareolar and eccentric to the nipple. Margins of the lesions are more frequently well defined, and calcifications are rarer and coarser than those occurring in female breast cancer. Gynecomastia usually appears as a fan-shaped density emanating from the nipple, gradually blending into surrounding fat. It may have prominent extensions into surrounding fat and, in some cases, an appearance similar to that of a heterogeneously dense female breast. Although there are characteristic mammographic features that allow breast cancer in men to be recognized, there is substantial overlap between these features and the mammographic appearance of benign nodular lesions. The mammographic appearance of gynecomastia is not similar to that of male breast cancer, but in rare cases, it can mask malignancy. Gynecomastia can be mimicked by chronic inflammation. All mammographically lucent lesions of the male breast appear to be benign, similar to such lesions in the female breast.
    Radiographics 05/1999; 19(3):559-68. DOI:10.1148/radiographics.19.3.g99ma01559 · 2.73 Impact Factor
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    ABSTRACT: Individuals affected by the autosomal recessive disease xeroderma pigmentosum (XP) are acutely sensitive to sunlight and predisposed to skin cancer on exposed areas. Cells cultured from XP patients are both UV sensitive and defective in the nucleotide excision repair of damaged DNA. These cellular phenotypes are amenable to experimental strategies employing complementation, an approach previously used to demonstrate the correction of XP-D phenotypes following the introduction of the XPD (ERCC2) gene. In the present study, we have characterized the genomic organization of the XPD (ERCC2) gene and found it to be comprised of 23 exons. These data were helpful in evaluating the functional integrity of alleles in two XP-D cell lines. In cell line GM436 a C-->G transversion was found at nucleotide position 1411 in the XPD (ERCC2) cDNA, a change expected to result in a Leu461Val substitution. Cell line XP67MA carries a C-->T transition in genomic DNA at nucleotide position 2176 in exon 22, introducing the termination codon TAG at amino acid 726. The latter would be expected to produce a protein truncated by 34 amino acids. Although expression of the normal XPD cDNA could be shown to correct the UV sensitivity phenotype in XP-D cells, cDNA constructs bearing either of the two mutations failed to yield complementation. These results confirm the role of ERCC2 in XP-D and illustrate the power of utilizing cellular phenotypes to evaluate the significance of single nucleotide substitutions.
    Human Molecular Genetics 11/1994; 3(10):1783-8. DOI:10.1093/hmg/3.10.1783 · 6.68 Impact Factor

Publication Stats

287 Citations
39.75 Total Impact Points

Institutions

  • 1999–2007
    • University of Texas Southwestern Medical Center
      • • Department of Pathology
      • • Department of Surgery
      Dallas, TX, United States
  • 1994
    • University of Texas at Dallas
      Richardson, Texas, United States