Segmental mediolytic arteritis. A clinicopathologic and ultrastructural study of two cases.

We describe the histopathologic and ultrastructural changes in two cases of segmental mediolytic arteritis (SMA) and summarize the clinical and pathologic findings in previous reports. SMA is initiated by the transformation of the arterial smooth-muscle cytoplasmic contents into a maze of dilated vacuoles containing edema-like fluid. With vacuolar rupture, the smooth-muscle cells are disrupted and the mediolytic process completed. Mediolysis is accompanied by fibrin deposition and hemorrhages at the adventitio-medial junction and within the media. Inflammation is inconstant and limited to the periadventitial tissues. Transmural mediolysis leads to the formation of arterial wall gaps--defects in the vascular wall bridged by a serofibrinous layer. The serosal and intramural arteries and arterioles of the jejunum and the epicardial coronary arteries were the targets of SMA in this report. SMA occurs in two clinical settings: (a) in abdominal muscular arteries and arterioles of predominantly elderly patients presenting either with ischemic bowel disease or shock, and (b) in the coronary arteries of neonates in conditions associated with severe hypoxemia. We conclude that SMA is the result of an inappropriate vasospastic response expressed in a splanchnic vascular bed undergoing vasoconstriction as a response to shock or severe hypoxemia.

Primary liposarcoma of the right atrium.

Primary intracardiac liposarcomas are among the rarest tumors of the heart, with a total of six reported cases. The previous reports have focused on clinical features with minimal histologic documentation. We report a primary right atrial liposarcoma showing extracardiac spread and three types of histologic differentiation. This case demonstrated that certain clinical and pathologic features are common to all intracavitary cardiac neoplasms, emphasizing the need for careful histologic examination.

Value of lymphocyte marker studies in diagnostic cytopathology.

The separation of lymphoreticular neoplasms from poorly differentiated epithelial and mesenchymal tumors and reactive processes can be a difficult problem in cytopathology. Immunodiagnostic techniques can be applied to cytologic specimens to detect cellular antigens, which may aid in their proper identification. We have reviewed 67 cytologic specimens in which immunoperoxidase techniques were employed using antibodies to common leukocyte antigen (HLE1), B-cell markers (B1, Leu 12 and kappa and lambda light chains), T-cell markers (Leu 1, OKT11, Leu 12 and kappa and lambda light chains), T-cell markers (Leu 1, OKT11, OKT4 and OKT8) and monocytes (OKM1 and LeuM1). These specimens included 33 body cavity fluids (21 pleural, 8 ascitic and 4 pericardial), 22 cerebrospinal fluids (CSF) and 12 fine needle aspirates (4 brain, 1 adrenal, 2 liver, 1 kidney, 3 retroperitoneal masses and 1 lymph node). The marker studies confirmed the initial cytomorphologic diagnoses in 31 specimens and modified the final diagnoses in 16 specimens. Markers in 20 specimens were noncontributory due to low cellularity or technical difficulties. Two problems may limit the usefulness of these procedures. First, many of the CSF specimens contained too few cells for adequate processing. Second, the mesothelial cells from pleural specimens often stained with HLE1. Our findings indicate that marker studies are of value in the diagnosis of problematic cases presenting as undifferentiated tumors in cytopathology.

Inappropriate use of the cerebrospinal fluid Venereal Disease Research Laboratory (VDRL) test to exclude neurosyphilis.

Only 3 of 2536 cerebrospinal fluid (CSF) VDRL tests ordered at the Johns Hopkins Hospital in 1980 were positive. Of patients on whom the test was ordered, 226 had a positive or borderline serum fluorescent treponemal antibody absorption test. Records from 156 (69%) of these patients, including all 3 with positive CSF-VDRL tests, were reviewed and showed that the diagnosis of neurosyphilis had been considered only in 44 (28%). One third of records lacked notations of historical and physical findings characteristic of neurosyphilis. Forty seropositive patients who had lumbar puncture to rule out asymptomatic neurosyphilis had negative CSF-VDRL tests; none had neurosyphilis diagnosed. Use of the CSF-VDRL test seemed to represent predominantly "box-checking" on the requisition to rule out neurosyphilis. Yet the test performs better when "ruling in" rather than ruling out neurosyphilis. The Centers for Disease Control should reevaluate its recommendation to rule out neurosyphilis in asymptomatic patients with untreated syphilis of greater than 1 year's duration, given the costs, risks, and dubious benefits.

P-glycoprotein expression in gastroesophageal adenocarcinomas, their metastases, and surrounding mucosa: a mapping study.

Previously, we identified P-glycoprotein in primary gastroesophageal adenocarcinomas and in adjacent mucosa. This study is a further investigation of P-glycoprotein expression in adenocarcinomas and benign mucosa. Sixteen resection specimens were studied (seven for gastric adenocarcinoma, seven for esophageal adenocarcinoma, one for adenocarcinoma at the gastroesophageal junction, and one for severe dysplasia in Barrett's esophagus). Multiple samples of tumor and mucosa were submitted according to a specimen diagram. Lymph node and distant metastases were studied when available. P-glycoprotein expression was identified in paraffin-embedded tissues by immunohistochemistry using monoclonal antibody C219 and was scored as the percentage of cells stained. P-glycoprotein was identified in six of 16 resection specimens. Intratumoral variability of C219 score was noted in three resections. No increase in expression was identified in lymph node or distant metastases as compared with primary tumors or in the invasive margin of the tumor as compared to the center. For every case in which tumors expressed P-glycoprotein, it was also diffusely present in all types of benign gastric and Barrett's mucosa, both adjacent to and distant from (up to 8 cm) the tumor. We also studied biopsies from 10 patients with Barrett's esophagus who did not have carcinoma. P-glycoprotein was only focally present in one of the 10 biopsies. Mucosa expressing P-glycoproteins may be the substrate from which a P-glycoprotein positive tumor arises.

Diffuse leptomeningeal seeding from a malignant spinal cord astrocytoma in a child with neurofibromatosis.

A 5-year-old child typical clinical features of neurofibromatosis presented with a history of suspected basilar meningitis and CT findings of enlarged optic nerves and an expanding left cavernous sinus mass. CSF cytologies and meningeal biopsy were unremarkable. At craniotomy, a mass confluent with the left trigeminal nerve was resected which had histologic characteristics of a nerve sheath tumor but was GFAP (glial fibrillary acidic protein) stain positive. Postmortem examination, 1 month following surgical resection, demonstrated a clinically unsuspected primary thoracic spinal cord astrocytoma with dissemination throughout the subarachnoid space, invasion of the trigeminal nerve and encasement of other cranio-spinal nerves. This unusual case emphasizes the occurrence of leptomeningeal spread in a clinically silent spinal cord glioma and the diagnostic value of immunohistochemistry.

Fine needle aspiration diagnosis of intraabdominal and retroperitoneal lymphomas by a morphologic and immunocytochemical approach.

We reviewed 238 fine needle aspiration biopsies (FNA) of intraabdominal or retroperitoneal (IA/RP) masses in 192 patients with known or suspected lymphoma. A limited battery of immunocytochemical stains, including kappa (k) and lambda (l) light chains and Leu-4, was performed in 104 aspirates. On hundred twenty-eight of the FNA were diagnostic of or consistent with lymphoma, and three were diagnostic of carcinoma. Twenty-eight were considered negative for malignancy and 79 were suspicious for lymphoma or were nondiagnostic. For 135 of the FNA, a histologic biopsy specimen was available for comparison purposes. Overall, only one false-positive result was seen in a specimen lacking immunocytochemical data. The sensitivity of FNA lymphoma diagnosis was 66%. False-negative results due to sampling error were not uncommon, giving a predictive value of a negative result as 42%. The classification of the lymphomas by FNA was identical to that of the surgical biopsy in 86% of specimens and concurrently discrepant in 6%. We conclude that the routine performance of immunocytochemical studies on FNA of IA/RP masses is a feasible and valuable technique. Whereas suboptimal sensitivity and sampling error may make a negative diagnosis unreliable, lymphoma marker studies (combined with morphology) allow for an accurate and confident diagnosis and subclassification of lymphoma in the majority of cases.