Lymphoid infiltrates of the stomach. Evaluation of histologic criteria for the diagnosis of low-grade gastric lymphoma on endoscopic biopsy specimens

Low-grade gastric lymphomas may be difficult to distinguish from benign inflammatory infiltrates on endoscopic biopsy specimens. Recent reports have suggested that so-called lymphoepithelial lesions (infiltration of lymphocytes into glandular epithelium) are characteristic of primary gastric lymphomas. We evaluated the presence and prominence of lymphoepithelial lesions and other histologic criteria in 25 low-grade gastric lymphomas (21 primary) and 58 benign inflammatory infiltrates to evaluate their utility in distinguishing benign from malignant gastric lymphoid infiltrates. The following features were associated only with lymphomas: (a) prominent (2-3 +) lymphoepithelial lesions (eight of 24 versus none of 58; p less than .0001); (b) Dutcher bodies (three of 25 versus none of 58, p = .05); and (c) moderate cytologic atypia (nine of 25 versus none of 58, p less than .0001). One or more of these features was seen in 18 of 25 gastric lymphomas (72%). Features more often associated with, but not limited to, lymphomas were dense (2-3 +) lymphoid infiltrates (25 of 25 versus five of 58, p less than .0001), rare or questionable lymphoepithelial lesions (11 of 24 versus 17 of 58, p = .01), muscularis mucosae invasion (20 of 20 versus 20 of 47, p less than .0001), ulceration (12 of 24 versus five of 58, p less than .0001), and mild cytologic atypia (eight of 25 versus six of 58, p less than .005). Germinal centers, crypt abscesses, and reactive epithelial atypia were seen with equal frequency in both types of infiltrate. Acute inflammation (2-3 +) was associated more often with inflammatory infiltrates (two of 25 versus 27 of 58, p less than .001). Our results suggest that dense lymphoid infiltrates with either prominent lymphoepithelial lesions, moderate cytologic atypia, or Dutcher bodies are highly suggestive and may be diagnostic of lymphoma. This constellation of findings is present in about 70% of endoscopic biopsy specimens of low-grade gastric lymphoma. In addition, the majority of cases of primary low-grade gastric lymphoma have morphologic, immunophenotypic, and clinical features that justify their inclusion in the category of low-grade lymphomas of mucosa-associated lymphoid tissue, whereas a minority are examples of lymphomatous polyposis of the gastrointestinal tract (centrocytic lymphoma).

Histological studies of the glenoid labrum from fetal life to old age

To help to resolve the controversy regarding the composition of the glenoid labrum, thirty-eight shoulders from cadavera were examined grossly and histologically. We used specimens for individuals of different ages so that we could determine what changes occur as a result of aging. In children and adults, the labrum appeared to be fibrocartilaginous tissue. The labrum was a separate anatomical structure that could be distinguished from the fibrous capsule of the shoulder. Neonatal labra were composed of primitive mesenchymal tissue containing only few chondrocytes that modulated into fibrocartilage in the first few years of life. Neonatal labra contained no elastin, whereas specimens from adults had rare elastin fibers. The labrum was sparsely vascularized throughout its substance, with no particular pattern of distribution. Vascularity decreased with increasing age of the individual.

Plasma cell myeloma with cleaved, multilobated, and monocytoid nuclei

The neoplastic cells in most cases of multiple myeloma closely resemble normal plasma cells. The authors report six cases of myeloma in which most of the neoplastic cells had cleaved, multilobated, or monocytoid nuclei and presented some diagnostic difficulty. All cases were clinically aggressive (five patients with stage III disease and one patient with stage II disease). Three patients died during their initial hospitalization, and three patients are alive with progressive disease from 5 to 14 months after combination chemotherapy. Immunohistochemical studies on paraffin-embedded tissue demonstrated monotypic immunoglobulin in each case (three lambda and three kappa). Recognition of these morphologic variants of neoplastic plasma cells is important to the pathologist to avoid erroneous diagnoses and to alert the clinician to an aggressive form of myeloma associated with a poor prognosis. Immunohistochemical studies on paraffin-embedded tissue sections are useful in the diagnosis of this tumor.

Primary lymphoma of bone. A B-cell neoplasm with a high frequency of multilobated cells

Primary lymphoma of bone is an uncommon neoplasm that can be difficult to diagnose and subclassify. Only in a few cases has the immunophenotype been determined with monoclonal antibodies. We evaluated the histological features and immunophenotype of 12 cases of primary lymphoma of bone. The patients ranged in age from 16 to 80 years (mean, 41 years) with a male:female ratio of 1:1. The sites involved included femur (three cases), humerus (two cases), tibia (three cases), pelvis (two cases), ulna (one case), and scapula (one case). All cases were diffuse large-cell lymphomas: nine large-cleaved (eight with multilobated cells), two large-cell not otherwise specified, and one immunoblastic. Sclerosis was noted in six cases. Immunohistochemical studies on frozen-tissue sections demonstrated staining with the following antibodies: 11 of 11 with CD45, 12 of 12 with CD20, eight of 12 with monotypic immunoglobulin (six IgG, two IgM, seven kappa, one lambda). Tumor cells were negative for T-cell markers in each case. Ten patients are alive and well 0.5-4.5 years (median, 1.5 years) following treatment with radiation or chemotherapy. Two patients had recurrence at another site 0.75 years and 4 years after the initial diagnosis, respectively. Primary bone lymphoma is a B-lineage large-cell lymphoma with an unusually high incidence of large-cleaved and multilobated cells. The frequency of IgG heavy chain expression suggests a post-germinal center stage of differentiation. Frozen section immunohistologic studies are useful in the diagnosis of this tumor. Aggressive therapy has resulted in a favorable outcome in most cases.

Lymphoproliferative disorders and hematologic malignancies following organ transplantation

Eleven allograft recipients (one cardiac, one hepatic, nine renal) at the Massachusetts General Hospital developed a lymphoproliferative disorder or leukemia. Six (all renal) patients received conventional immunosuppressive therapy (CIT), four received cyclosporin A (CsA) (one cardiac, one hepatic, two renal), and one received CIT for his first transplant and CsA for his second transplant (both renal). The interval from transplant to onset of the hematologic disorder ranged from 2 mo to 3 yr in the CsA group and from 6 mo to 9 yr in the CIT group and was 16 yr in the patient with two allografts. There were eight malignant lymphomas, seven of which were extranodal, (four immunoblastic, one large noncleaved cell, one small noncleaved cell, one plasmacytoma, one unclassifiable), one case of polymorphic diffuse B cell hyperplasia and two cases of acute myeloid leukemia. Frozen section immunohistochemistry in six cases showed monotypic immunoglobulin in four lymphomas, (including the plasmacytoma), an immunoglobulin-negative B cell phenotype in one lymphoma, and polytypic immunoglobulin in the case of polymorphic hyperplasia. One lymphoma showed a monotypic immunoglobulin-producing B cell population in one site and an immunoglobulin-negative B cell population in another site. With an immunoglobulin heavy chain gene-specific probe, Southern blot analysis of tissue from these two sites revealed two distinct rearrangements. When tissue from a second case of lymphoma was analyzed by Southern blot, identical rearrangements of the heavy chain gene were found in tumor from two separate sites. Similar to the experience of others, we find an increased incidence of lymphoma and a slightly increased incidence of acute myeloid leukemia in allograft recipients. In contrast to other reports, we found a predominance of monoclonal B cell malignancies, a more polymorphous histologic appearance of the lymphoproliferative disorders in CsA patients, and one case each of "multiclonal" and "monoclonal" lymphomas when tumor from separate sites was tested for gene rearrangement.

Uterine leiomyomas with lymphoid infiltration simulating lymphoma. A report of seven cases

Seven women, 35-50 years of age, had uterine leiomyomas with lymphoid infiltration. The leiomyomas ranged from 2 to 12 cm in greatest dimension and contained a variably dense infiltrate of small lymphocytes with scattered larger lymphoid cells and occasionally, numerous plasma cells; germinal centers were identified in some cases and ranged from large and florid to inconspicuous; rarely, eosinophils were present. Most of the tumors contained focal to extensive areas of sclerosis. In all the cases in which adjacent myometrium was available for examination, the lymphoid infiltrate was confined to the leiomyoma or was present to only a minor extent in the adjacent myometrium. Significant lymphoid infiltration of uterine leiomyomas, which appears to be a reactive process, has not been described previously. The polymorphous nature of the infiltrate and its confinement to the leiomyoma distinguish it from malignant lymphoma.

Mucoepidermoid lung tumors

Mucoepidermoid lung tumors are uncommon, representing 0.2% of all lung tumors and 1% to 5% of bronchial adenomas. Eighteen patients with mucoepidermoid tumors are reported. There were 10 male and 8 female patients with a mean age of 36.8 years (range, 9 to 62 years). On the basis of mitotic activity, cellular necrosis, and nuclear pleomorphism, we subclassified these tumors as low grade (15 patients) or high grade (3 patients). The achievement of complete resection and low-grade versus high-grade staging correlated with prognosis. All 12 patients who had a low-grade tumor that was completely excised are alive with no evidence of disease at a mean follow-up of 4.7 years (range, 1 to 27 years). All high-grade tumors proved fatal within 16 months. Two of the 3 high-grade tumors were unresectable because of extensive local disease. Patients with low-grade tumors and microscopically positive margins require close follow-up and can undergo a successful repeat resection. Nine of the 16 resections were sleeve resections, high-lighting the importance of conservative lung-sparing procedures in these central airway tumors. Both patients with an unresectable high-grade tumor had radiation therapy postoperatively and died 11 months later. The role of radiation therapy with high-grade tumors or incomplete resection has yet to be determined.

Intravascular lymphomatosis (malignant angioendotheliomatosis). A B-cell neoplasm expressing surface homing receptors

We report the clinical and immunohistochemical features of six cases of intravascular lymphomatosis. All patients presented with symptoms referable to central nervous system (CNS) involvement. In two patients, the diagnosis was made on brain biopsy specimens. In the remaining four cases, diagnosis was made at autopsy. Three of the four autopsied patients had focal extravascular lymphoma, diffuse large cell type. In all five cases tested, immunohistochemical stains on paraffin-embedded sections confirmed the lymphoid nature of the malignant cells. Stains on frozen sections in one case, and on paraffin-embedded tissue in the other four cases, demonstrated B-lymphocyte lineage. In the remaining case, electron microscopy confirmed the lymphoid nature of the tumor cells. All three cases tested expressed the Hermes 3-defined homing receptor antigen and lacked peanut agglutinin receptors. Our results are consistent with other reports confirming the lymphoid nature of so-called malignant angioendotheliomatosis. Our limited analysis of surface receptor molecules suggests that the expression of the homing receptor for high endothelial venules is not in itself responsible for the unusual intravascular location of these cells.

A comparison of paraganglioma, carcinoid tumor, and small-cell carcinoma of the larynx

Laryngeal paraganglioma, carcinoid tumor, and small-cell carcinoma are rare. Histologically they are similar to analogous tumors in other locations but may be difficult to identify in small biopsy specimens. We compared the light microscopic, histochemical, immunohistochemical, and electron microscopic features of two laryngeal paragangliomas, one carcinoid tumor, and six small-cell carcinomas. The paraganglioma chief cells stained with Grimelius stain and for chromogranin and neuron-specific enolase. The carcinoid tumor cells stained with Grimelius stain and for chromogranin, serotonin, neuron-specific enolase, and keratin. The small-cell carcinoma cells stained for keratin and neuron-specific enolase. The patients with paragangliomas and carcinoid tumor remain healthy through 20 months of follow-up. Four of the patients with small-cell carcinomas have died. Distinction between these tumors is warranted by differing histologic appearances, staining characteristics, and biologic behavior.

Pseudoglandular schwannoma

The glandular schwannoma is a rare variant of schwannoma in which the focally occurring glands are lined by cells resembling intestinal or respiratory type epithelium, or ependyma. The schwannomas harboring these glands are usually malignant and usually arise in the setting of von Recklinghausen's disease. The case presented in this report is that of a 43-year-old man who had no evidence of neurofibromatosis, and developed a benign schwannoma that contained multiple well formed gland-like structures. The cells lining the glands, when examined ultrastructurally and histochemically, proved to be Schwann cells, a unique finding that may provide a clue to the histogenesis of the glandular schwannoma.

"Adenoid cystic" carcinoma and adenoid basal carcinoma of the uterine cervix. A study of 28 cases

Adenoid cystic carcinoma (ACC) and adenoid basal carcinoma (ABC) of the uterine cervix are rare tumors that have often been regarded as a single entity. We studied 28 cases of these neoplasms, with 14 cases in each category. Most patients were over 60 years of age, and there was a high proportion of black women. The majority of the women with ACC presented with postmenopausal bleeding and had an obvious mass on pelvic examination. Despite the tumors' architectural similarity to ACC of the salivary gland, microscopic examination of the cervical carcinomas showed necrosis, a high mitotic rate, and greater nuclear pleomorphism. In all but one of the cases, the tumor cells were negative for S-100 protein on immunoperoxidase staining--a finding that provides evidence against a myoepithelial component. However, S-100-positive dendritic cells were present in the stroma of the tumors and among the neoplastic cells. The patients with ABC were usually asymptomatic, without a gross abnormality of the cervix. Microscopic examination disclosed small nests of basaloid cells, almost always beneath, and often arising from, in situ or small invasive squamous cell carcinomas. In contrast to ABC, ACC was often complicated by local recurrence or distant metastasis. We conclude that ACC of the uterine cervix differs from ACC of salivary gland origin and is also distinct clinically and pathologically from cervical ABC.

Relapsing central and peripheral demyelinating diseases. Unusual pathologic features

We treated a patient who had a demyelinating peripheral neuropathy and a central nervous system inflammatory demyelinating disease. The unusual pathologic feature of dense infiltrates of atypical macrophages was observed in many areas of the brain; otherwise the process had several features in common with either multiple sclerosis or chronic relapsing experimental allergic encephalomyelitis. The illness followed "swine-flu" inoculation; exacerbation followed pneumococcal vaccination.

Artemia hemoglobins. Increase in net synthesis of the beta-polypeptide (relative to the alpha-polypeptide) in hypoxia

Previous studies have shown that in the brine shrimp there are three dimeric hemoglobins with polypeptide composition alpha 2, alpha beta, beta 2. Concentrations of the alpha- and beta-polypeptides increase in hypoxia. We now report a two-dimensional electrophoretic method for assay of radiolabelled polypeptides in each hemoglobin. Net synthesis (synthesis minus degradation) of the beta-chain, relative to that of the alpha-chain, increases more than 3-fold (in male and female adults) within 3 days following a downshift in oxygen concentration from 0.2 to 0.1 mM in the culture medium. 3 days after downshift (2 days after in vivo incorporation of radiolabelled leucine), the beta-homodimer contained 10-20% of the radiolabel in the three hemoglobins although beta 2 was usually not detectable in the protein stain of an overloaded gel. The amount of radioactive leucine incorporated per unit amount of protein was more than 300-times greater in the beta 2 homodimer than in the beta-subunit of the heterodimer, suggesting that beta 2 does not dissociate rapidly during electrophoresis on the first dimension non-denaturing gel. This evidence for stable association of the two beta-monomers and the 5-8 heme-binding domains within each monomer (in vivo and during electrophoresis on non-denaturing gels) allows us to exclude one of two alternative interpretations of genetic data published previously. We present an independent line of evidence for the dimer model of the native hemoglobins (which states that each polypeptide has many heme-binding domains).