Nelson G. Ordóñez

Salivary epithelial-myoepithelial carcinomas of intercalated ducts: A clinical, electron microscopic, and immunocytochemical study☆

The salivary epithelial-myoepithelial carcinoma of intercalated duct origin is a distinctive, biologically low-grade carcinoma with a predilection for the parotid gland. Nine examples from the M.D. Anderson Hospital in Houston, Texas, bring the number of published cases to 33. Immunocytochemical (S-100 protein, myosin, and keratin) and electron-optic studies strongly support an active myoepithelial cell participation in the histogenesis of these carcinomas.

Ulrastructure of Liver Cell and Bile Duct Carcinomas

The primary concerns of the surgical pathologist examining a biopsy specimen are whether a particular neoplasm is originating within the liver or is metastatic and, if a primary, whether differentiation is toward liver cells or bile ducts. The present study was undertaken in the hopes of providing a broader concept of the ultrastructural spectrum of liver cell carcinoma (LCC) and a more precise understanding of the changes occurring in these neoplasms with dedifferentiation. The 20 liver cell carcinomas, 13 bile duct carcinomas (BDC), and 3 hepatoblastomas were studied ultrastructurally and the findings correlated with light microscopic sections stained by hematoxylin-eosin and the periodic acid-Schiff procedure with and without prior diastase digestion. Immunocytochemical staining for alpha 1-antitrypsin was carried out on selected tumors. Ultrastructural study can be useful in the distinction of LCC from BDC in the minority of cases in which this is difficult by light microscopy. While true mixed tumors appear to be uncommon, duct formation can be simulated by LCC cells. The extent to which electron microscopy will enable the pathologist to separate metastatic neoplasms in the liver from primary liver cell tumors depends on the relative ultrastructural features. Assessment of the value of electron microscopy as an aid to light microscopy in the histologic grading of LCC and BDC will require further study.

Percutaneous needle biopsy of soft tissue tumors guided by ultrasound and computed tomography

Ultrasound and computed tomography (CT) guided percutaneous needle biopsy of soft tissue lesions was performed in 39 patients. A correct diagnosis was obtained in 35 of 42 biopsies, with an overall accuracy rate of 83%. No false-positive diagnoses were obtained, and no complications related to the procedure were encountered. The value of this technique in the management of selected patients with soft tissue masses is detailed.

Immunoperoxidase localization of prostatic acid phosphatase in prostatic carcinoma with sarcomatoid changes

Immunoperoxidase staining of tissue for prostatic acid phosphatase has been useful in confirming the prostatic origin of metastatic deposits. This technique was used on the prostate tumors of 2 patients to differentiate between a true carcinosarcoma and a pure epithelial carcinoma with sarcomatoid changes. Positive staining for prostatic acid phosphatase in both the sarcomatoid element, as well as the area of well-differentiated carcinoma, confirmed the common epithelial cell origin of these components. Electron microscopy further confirmed these findings by demonstrating desmosomes in the sarcomatoid areas. Although each type of tumor is rare, differentiation between true carcinosarcomas and true carcinomas with sarcomatoid changes is important to elucidate further their different clinical behaviors and responses to therapy.

Pitfalls of CT Findings in Post-Therapy Testicular Carcinoma

Abstract: Computed tomography demonstrated fibrotic or necrotic lesions in the retroperitoneum and liver that were indistinguishable from viable tumor in three patients who had undergone therapy for testicular carcinoma. Therefore, residual masses after therapy may not signify viable disease.

Renal cell carcinoma metastatic to penis

Abstract Metastasis from renal cell carcinoma to the penis is rare. We report on 2 patients: in one, priapism developed and in the other, diffuse penile enlargement secondary to metastatic disease.

Intraoral Kaposi's sarcoma: A correlated light microscopic, ultrastructural, and immunohistochemical study

Oral mucosal lesions of Kaposis sarcoma are a common finding in patients with acquired immunodeficiency syndrome (AIDS). The histologic features of Kaposis sarcoma vary, depending on the clinical stage of the lesion. Endothelium-lined vessels are the principal feature of early, macular lesions, while spindle cells dominate late-stage, nodular lesions. The histogenesis of both components remains controversial. In this study, biopsy specimens of intraoral Kaposis sarcoma from 10 patients with AIDS were studied by light and electron microscopic examination and by immunoperoxidase staining with the endothelial markers, factor VIII-related antigen and Ulex europeaus agglutinin I. The results of this study support a vascular origin for both the endothelium-lined vessels and the spindle cells. The latter appear to represent vascular endothelial cells in various stages of differentiation. The histologic features that are useful in the diagnosis of intraoral Kaposis sarcoma are reviewed.

Hemangiopericytoma of kidney

Abstract Hemangiopericytoma of the kidney is extremely rare. A case of hemangiopericytoma of the right kidney with extensive vena caval tumor thrombus is reported. The typical hemangiopericytic pattern by light microscopy and the ultrastructural finding of pericyte-like cells were the basis for making this diagnosis.

Crystals and Alpha-1-Antitrypsin-Reactive Globoid Inclusions in an Islet Cell Tumor of the Pancreas

An islet cell tumor of the pancreas with unusual light microscopic, ultrastructural, and immunocytochemical features is reported. In addition to secretory granules and positive immunostaining for pancreatic polypeptide, the tumor contained globoid intracytoplasmic inclusions by light and electron microscopy, which correlated with a positive immunoreaction for alpha-1-antitrypsin, and Reinke-like crystals.

Primary localized amyloidosis of male urethra (amyloidoma)

Amyloidosis of the urethra is extremely rare. The first reported case of amyloidosis of the fossa navicularis is presented.