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Biomedical subjects

Mohamed E Salama

Publications and source records attributed to Mohamed E Salama.

8 recordsLinked to original sources

Spectrum of epithelial neoplasms in end-stage renal disease: an experience from 66 tumor-bearing kidneys with emphasis on histologic patterns distinct from those in sporadic adult renal neoplasia.

Most (up to 71%) of renal cell neoplasms occurring in patients with end-stage renal disease (ESRD), particularly with acquired cystic disease of the kidney (ACDK), have been reported to be papillary renal cell carcinoma (RCC). Our initial experience with tumors in such a setting indicated that many tumors were histologically difficult to classify into the known subtypes of RCC or had features that were different from those in sporadically occurring RCCs. In this study on 66 ESRD kidneys (52 of which showed features of ACDK) removed because tumors were detected in them, we found two major groups of RCC. Overall, there were 261 grossly identified tumors in these kidneys, and many additional tumors were observed on microscopic evaluation in some. Of the two major groups of RCCs, one consisted of tumors similar to those seen in sporadic settings (ie, clear-cell, papillary, and chromophobe RCC), and these formed the dominant mass in 12 (18%), 10 (15%), and 5 (8%) of the 66 kidneys, respectively. The other group consisted of two subtypes of RCC that appear quite unique to ESRD. The more common tumor that we have designated as "acquired cystic disease-associated RCC" was seen as the dominant mass in 24 (36%) of 66 of the kidneys, and it formed the most common tumor type among the smaller nondominant masses, as well. It was characterized by a typical microcystic architecture, eosinophilic cytoplasm with Fuhrman's grade 3 nuclei, and frequent association with intratumoral oxalate crystals. Additionally, these tumors frequently, but usually focally, exhibited papillary architecture, and clear cytoplasm. These tumors occurred only in kidneys with ACDK, and not in noncystic ESRD. The other category was "clear-cell papillary RCC of the end-stage kidneys," present as the dominant mass in 15 (23%) of the 66 kidneys and occurring in both the ACDK and noncystic ESRD. These predominantly cystic tumors showed prominent papillary architecture with purely clear-cell cytology. Immunohistochemical studies in tumors with histology similar to the known subtypes of sporadic RCC showed immunoprofiles similar to that reported in sporadically occurring tumors. The two subtypes of RCC unique to ESRD had distinctive immunoprofiles supporting their separate morphologic subcategorization. Only the acquired cystic disease-associated RCC showed lymph node metastases in 2 cases and sarcomatoid features in 2 more cases. One of the latter 2 died with widespread metastatic disease within 34 months of nephrectomy. Thus, a broad spectrum of renal cell tumors exist in ESRD, only some of which resemble the sporadic RCCs. Acquired cystic disease-associated RCC is the commonest tumor subtype in ESRD, and biologically it appears to be more aggressive than the other tumor subtypes in ESRD.

Adult↗

Platelet function testing to assess effectiveness of platelet transfusion therapy.

BACKGROUND: Posttransfusion corrected count increments (CCI) following administration of platelets is the standard method for assessing effectiveness of platelet transfusion therapy. However, improvement in platelet count following transfusion may not necessarily indicate improvement in platelet function or restoration of primary hemostatic capacity. To address this possibility, we investigated the effectiveness of platelet transfusion based on results of the Platelet Function Analyzer (PFA-100) and post-transfusion CCI. INVESTIGATION DESIGN AND METHODS: Platelet transfusion requests with different indications received at the blood bank were evaluated for inclusion in the investigation. Pre-transfusion, the following laboratory tests were performed: (1) PFA-100 assays (blood collected in 3.2% buffered sodium citrate) performed with CEPI and CADP test cartridges; (2) complete blood count (in EDTA) and platelet count; and (3) routine coagulation profile including PT, PTT, fibrinogen and D-Dimer. Only patients with normal coagulation profiles were included. The same set of tests were performed on a new blood sample collected 10-60 min post-transfusion. Chart review and clinical evaluation for response to platelet therapy were performed on each occasion of transfusion. RESULTS: Thirty-one patients, five of whom were transfused on more than one occasion were evaluated. Thirty-five transfusion incidents were included. Posttransfusion outcomes were divided into two groups--those that resulted in shortening (>40 s) or normalization of the closure time (Group A) and those that had no change or greater prolongation of the closure time (Group B) when compared to the pre-transfusion value. Seventeen and eighteen transfusion episodes were categorized as Groups A and B, respectively. In Group A with improved PFA testing, nine patients had bleeding as indication for transfusion and six of these had concomitant improvement in their clinical picture as confirmed by control of hemorrhage. In contrast in Group B with no improvement in PFA testing, seven patients had bleeding as indication for transfusion and none showed cessation of hemorrhagic symptoms. These findings were statistically significant (p=0.0114). Similar evaluation using the post-transfusion CCI showed no correlation to bleeding symptoms in these patients (p-=0.500). CONCLUSIONS: In this evaluation, platelet function testing using the PFA-100 provided a better indication of transfusion outcome than did the post-transfusion CCI. Using this approach, PFA-100 may be an effective aid for supporting platelet transfusion decisions and may further aid in improving management of the hospital blood bank platelet inventory.

Adult↗

Primary cutaneous mucinous carcinoma: presence of myoepithelial cells as a clue to the cutaneous origin.

BACKGROUND: Primary cutaneous mucinous carcinoma (PCMC) is a rare malignancy with probable apocrine differentiation. It is important to differentiate it from metastatic mucinous carcinoma (MMC), especially from the breast. The histologic and immunohistochemical features overlap between PCMC and breast mucinous carcinomas. In this study, we introduce the presence of myoepithelial component in PCMC as a new morphologic parameter to distinguish it from MMC from either breast or sites elsewhere in the body. MATERIALS AND METHODS: We studied 7 cases of PCMC. The possible in situ component in the tumor was assessed by the presence of a peripheral myoepithelial cell layer. Myoepithelial cell differentiation was confirmed with immunohistochemical stains for p63, CK 5/6, calponin, smooth muscle actin (SMA), HHF-35, and CD10. Estrogen and progesterone receptor (ER/PR), gross cystic disease fluid protein (GCDFP 15), CK7, CK20, and S-100 immunostains were also performed. RESULTS: Histologically, multiple small monomorphic epithelial islands floating in multilocular pools of mucin characterized the tumor. Focally, epithelial islands were bordered by dermal connective tissue at the periphery of mucin pools. Secretory snouts were apparent in all cases providing evidence for apocrine differentiation. In 5 of the 7 cases, an in situ component was identified as epithelial islands being bounded by a myoepithelial layer, which was highlighted by p63, CK 5/6, calponin, SMA, and HHF-35. ER/PR and CK7 were positive in all the cases. GCDFP-15 and CD10 were focally positive in the tumor cells and myoepithelial cells, respectively. All 7 cases were negative for S-100 and CK 20. CONCLUSION: We conclude that an in situ component is frequently present in PCMC (5/7) and may help in distinguishing this entity from MMC, especially of breast origin. Furthermore, it may provide insight into the pathogenetic mechanism of mucinous carcinoma evolving from in situ carcinoma with luminal mucinous distention to cellular tumor with a little surrounding mucin.

Adenocarcinoma, Mucinous↗

Chondroid syringoma. Cytokeratin 20 immunolocalization of Merkel cells and reappraisal of apocrine folliculo-sebaceous differentiation.

CONTEXT: Chondroid syringoma (CS) is a benign cutaneous adnexal tumor with epithelial and stromal components. Epithelial components derived from folliculo-sebaceous-apocrine germ are evident in apocrine but not in eccrine CS. OBJECTIVES: To further characterize pilosebaceous differentiation and to identify the presence of Merkel cells in the areas of follicular differentiation. DESIGN: Histologic type, folliculo-sebaceous differentiation, character of stroma, and presence or absence of Merkel cells by cytokeratin (CK) 20 immunoreactivity were evaluated in 25 CSs (22 apocrine and 3 eccrine) from the surgical pathology files of Henry Ford Hospital (Detroit, Mich). RESULTS: Most CSs occurred in the head and neck region of patients aged 40 years or older. We found no significant difference in sex, age, or location between apocrine and eccrine types. The stroma varied from myxoid (100%) to chondroid (59%), with various amounts of fat (59%) and ossification identified in 2 cases (9%) of apocrine type, but was homogeneously myxoid in the eccrine type. Follicular and sebaceous differentiation was found in 64% and 32% of apocrine CSs, respectively. Only 2 (14%) apocrine CSs with follicular differentiation were positive for CK20 (a few scattered cells in one case and numerous grouped cells in the other in association with follicular epithelium). No correlation was found between type of stroma and the presence of Merkel cells. Scattered Merkel cells were identified in 83% of normal hair follicles and in 33.3% of normal epidermis. CONCLUSION: A high proportion of apocrine CSs show folliculo-sebaceous differentiation. The presence of Merkel cells in foci of follicular differentiation of CS supports the hypothesis that Merkel cells may be an integral constituent of follicles. To our knowledge, the presence of Merkel cells in CS, particularly in proliferative form, has not been described previously in the literature.

Adenoma, Pleomorphic↗

Intraspinal endodermal cyst: ultrastructural study of abnormal cilia.

Abnormal cilia were demonstrated in the lining epithelial cells of three cases of intraspinal endodermal (bronchogenic) cyst. The changes comprised a wide spectrum of ultrastructural abnormalities, including (a). cilia with abnormal axonemal microtubules, (b). swollen cilia, (c). compound cilia with or without excessive ciliary matrix, (d). naked cilia without limiting membrane, and (e). intracytoplasmic cilia and aggregates of microtubules. Of these, compound cilia and swollen cilia were most common. Cilia with dynein arm deficiency were not observed. Ciliary abnormalities found in the present study were very similar to those described in the bronchial epithelium of various diseases. The present findings suggest that the lining epithelium of intraspinal endodermal cyst shares similar ciliogenesis and susceptibility to abnormal ciliary formation as that of the bronchial epithelium.

Adult↗

Solitary sclerotic fibroma of skin: a possible link with pleomorphic fibroma with immunophenotypic expression for O13 (CD99) and CD34.

BACKGROUND: Solitary sclerotic fibroma (SF) presents as a well circumscribed dermal nodule, composed of sparse spindle cells with alternating wavy collagen fibers arranged in a storiform pattern. The histogenesis and nature of this histologically distinct lesion are uncertain. Whether this peculiar tumor represents a true hamartoma or a degenerating end of various fibrous lesions such as pleomorphic fibroma (PF), dermatofibroma, or angiofibroma is still controversial. High proliferating index of spindle cells in SF argues against the possibility of being a degenerating end product of another lesion. METHODS: We studied morphological features and immunoprofile of eight SFs, in comparison with four PFs, one collagenized dermatofibroma, two angiofibromas, and two periungual fibromas. Immunostains for CD34, CD31, O13 (CD99), Factor XIIIa, S-100, CD68 (KP-1), and MIB-1 were carried out using a labeled streptavidin-biotin method with DAKO-automated immunostainer. Paraffin blocks of two SFs were reprocessed for electron microscopic studies. Clinical data of all patients with SF were also reviewed. RESULTS: Spindle cells and pleomorphic cells in SF and PF showed diffuse immunoreactivity for CD34 and O13 but were negative for CD31, S-100, and CD68. Spindle cells in one dermatofibroma and one angiofibroma were positive for Factor XIIIa. Proliferating index (MIB-1) was very low in all cases of SF, contradicting some previous reports. CONCLUSIONS: SF is a fibrotic lesion with cells positive for CD34 and O13. It shares a common immunoprofile with PF but is distinct from dermatofibroma and other common spindle cell lesions of skin. O13 expression in SF has not been previously described.

12E7 Antigen↗