Juan Rosai

Malignant small cell tumor of the thoracopulmonary region in childhood. A distinctive clinicopathologic entity of uncertain histogenesis

This report describes a unique clinicopathologic entity characterized as a malignant small cell tumor of the thoracopulmonary region in 20 children and adolescents (average age 14.5 years). There was a female predilection (75%) for this tumor which appeared to originate in the soft tissues of the chest wall or the peripheral lung. The neoplasm tended to recur locally and did not seem to disseminate as widely as some of the other small cell tumors of childhood (rhabdomyosarcoma, Ewings sarcoma, neuroblastoma and malignant lymphoma). However, the median survival was only 8 months. Electron microscopy of 3 cases suggested a neuroepithelial derivation, but, at the present, the histogenesis remains a subject for further investigation.

Intra-abdominal desmoplastic small round-cell tumor. Report of 19 cases of a distinctive type of high-grade polyphenotypic malignancy affecting young individuals.

Nineteen cases of a distinctive type of malignant smallcell tumor are presented. The main features of the entity are as follows: a predilection for adolescent males (mean age: 18.6 years); predominant or exclusive intraabdominal location, with only inconstant and secondary organ involvement: nesting pattern of growth; focal rhabdoid features; intense desmoplastic reaction; immunohistochemical reactivity for epithelial [keratin, epithelial membrane antigen (EMA)], neural [neuron-specific enolase (NSE)], and muscle (desmin) markers; and highly aggressive behavior. It is proposed that this represents yet another member of the continuously enlarging and evolving family of small round (blue) cell tumors of infancy and childhood that features, more than any other member of this group, the capacity for simultaneous multidirectional phenotypical expression.

Aggressive angiomyxoma of the female pelvis and perineum. Report of nine cases of a distinctive type of gynecologic soft-tissue neoplasm.

Nine case of a distinctive soft tissue tumor of the female pelvis and perineum are described. They were characterized by their occurrence in young women (ages 21–38), large size (up to 60 X 20 cm), locally infiltrative nature, and grossly gelatinous appearance. The initial clinical impression was usually that of a Bartholin gland cyst. The microscopic appearance was that of spindle or stellate cells widely separated by a loose myxoid stroma focally rich in collagen fibrils, a prominent vascular component, including many large thick-walled vessels without an arborizing pattern, and foci of proliferating glandular elements in two cases. Mitotic activity was exceedingly low. Ultrastructural study of the spindle cells showed features consistent with myofibroblastic differentiation. Four patients developed large local recurrences; one tumor recurred twice, 14 and 15 years after initial excision. No distant metastases have been documented to date, and all patients are alive and well.The differential diagnosis of this unusual tumor includes myxoma, myxoid liposarcoma, sarcoma botryoides, myxoid variant of malignant fibrous histiocytoma, nerve sheath myxoma, and other soft tissue tumors with secondary myxoid changes. We have chosen the term “aggressive angiomyxoma” for this neoplasm to emphasize the neoplastic nature of the blood vessels and its locally infiltrative and recurrent nature.

Sinus histiocytosis with massive lymphadenopathy: a pseudolymphomatous benign disorder. Analysis of 34 cases.

Thirty‐four cases of sinus histiocytosis with massive lymphadenopathy (SHML) are analyzed. Most of the cases involved Negro children and were characterized by cervical lymphadenopathy, which was often bilateral, painless, and of massive proportions. Other lymph node groups were sometimes involved. Fever, leukocytosis with neutrophilia, elevated erythrocyte sedimentation rate, and hypergammaglobulinemia were common features. The involved lymph nodes showed pericapsular fibrosis; dilation of sinuses; presence of numerous intrasinusal histiocytes with abundant clear cytoplasm, occasionally multinucleated, foamy or atypical; and large collectiions of plasma cells. A striking and constant finding was the presence of many lymphocytes and other hematopoietic cells within the cytoplasm of the sinus histiocytes. The diease characteristically followed a protracted clinicl course, with eventual spontaneous regression of the lymphadenopathy and total recovery in most cases. The etiology and pathogenesis are unknown. In this regard, the most likely possibilities include a specfic infectious process and a status resulting from an immunologic deficit.

Borderline Epithelial Lesions of the Breast

The concept of borderline epithelial lesions of the breast remains a controversial one, both at the conceptual and practical levels. The work of Page and collaborators (17–20) has suggested the existence of a continuum between hyperplasia and carcinoma in situ, and that the risk for the development of invasive carcinoma correlates with the degree of proliferation and atypia. A small survey made among a group of five experienced surgical pathologists to test the degree of interobserver variability in this field indicates that this variability remains unacceptably high. Unfortunately, none of the special techniques that have been employed to date in an attempt to achieve a sharper and more reproducible separation between the various groups has yet fulfilled this goal.Since an element of subjectivity in the microscopic interpretation persists and is unlikely to be completely eliminated, and in view of the fact that the current terminology suggests a sharper division than what the evidence seems to indicate, consideration could be given to adopt a terminology such as mammary intraepithelial neoplasia (MIN) of either ductal or lobular types, followed by a grading system.

Thymic carcinoma. A clinicopathologic study of 60 cases

Clinicopathologic features of 60 patients with thymic carcinoma were studied. Patients ranged in age from 10 to 76 years (mean, 46), of whom 24 were females and 36 were males. Overall survival at 1, 3, and 5 years was 56.6%, 40%, and 33.3%, respectively. The following morphologic features were correlated with survival: type of tumor margins; presence or absence of a lobular growth pattern; nuclear atypia; necrosis; mitotic activity; and histologic tumor type and grade. Eighty eight percent of patients with poorly circumscribed/infiltrating neoplasms died of their tumors as compared with 16.6% of patients with well‐circumscribed neoplasms (P < 0.0000). Of patients whose tumors had mitotic counts exceeding 10/10 high‐power fields (HPF), 84.3% died, as compared with 21.4% of patients with lower mitotic counts (P < 0.0000). of patients whose tumors showed lack of lobular growth pattern, 91.6% died, as compared with 29% of those whose tumors had a lobular growth pattern (P < 0.0000). Finally, 84.6% of patients whose tumors displayed a high‐grade histology (lymphoepithelioma‐like carcinoma, small cell/neuroendocrine carcinoma, clear cell carcinoma, sarcomatoid carcinoma, and anaplastic/undifferentiated carcinoma) died of tumor, as compared with 0% of patients whose tumors were of low‐grade histology (well‐differentiated squamous carcinoma, mucoepidermoid carcinoma, and basaloid carcinoma) (P < 0.0000). Evaluation of the various treatment modalities used to treat these patients did not yield any statistically significant correlations with survival. Two clinically distinct groups of patients were identified: one after a relatively favorable clinical course with long survival, and one after a rapidly fatal outcome. The morphologic features of the tumors in these patients correlated well with their clinical behavior; histologic type (and the grade to which it was assigned) constituted the most reliable and important predictor of prognosis.

Initial Results from a Prospective Cohort Study of 5583 Cases of Thyroid Carcinoma Treated in the United States during 1996 An American College of Surgeons Commission on Cancer Patient Care Evaluation Study

The American College of Surgeons Commission on Cancer (CoC) has conducted national Patient Care Evaluation (PCE) studies since 1976.

Acinar Cell Carcinoma of the Pancreas: A Clinicopathologic Study of 28 Cases

We have examined the microscopic appearance, immunohistochemical staining properties, and clinical behavior of 28 cases of acinar cell carcinoma of the pancreas. Two of the tumors occurred in children. The adult patients ranged in age from 40 to 81 years (mean, 62 years). Males greatly outnumbered females, and most of the patients were white. Presenting symptoms were nonspecific, and jaundice was infrequent. The frequently reported complications from increased serum lipase levels (i.e., arthralgias and subcutaneous fat necrosis) were present in only 16% of the patients. Grossly, the tumors were relatively circumscribed and fleshy, averaging 10.8 cm, with occasionally extensive hemorrhage and necrosis. Microscopically, the tumors were very cellular and characteristically lacked a desmoplastic stroma. Acinar, solid, trabecular, and glandular patterns of growth were identified; individual tumors were usually mixed. Nuclei were round to oval, with minimal pleomorphism and single prominent nucleoli. Mitotic activity was variable. In general the cytoplasm was moderately abundant, eosinophilic, and granular, but many of the solid tumors had cells with scanty cytoplasm. Characteristic periodic acid-Schiffpositive, diastase-resistant cytoplasmic granules were demonstrated in >90% of the cases, and the butyrate esterase histochemical stain for lipase activity was positive in 73%. Immunohistochemically, there was positivity for trypsin in 100% of the cases, for lipase in 77%, for chymotrypsin in 38%, and for amylase in 31%. A minor endocrine component was recognized with antibodies against chromogranin or islet cell hormones in 42% of the tumors. Ultrastructurally, exocrine secretory features were present, with polarized cells showing microvillilined lumina, abundant rough endoplasmic reticulum, and 125-1,000-nm zymogen-like granules. In addition, many cases showed pleomorphic electron-dense granules measuring up to 3,500 nm and containing fibrillary internal structures. Follow-up information was available in 88% of the cases. Half of the patients had metastatic disease at presentation and an additional 23% subsequently developed metastases, which were usually restricted to the regional lymph nodes and liver. The mean survival for all cases was 18 months, with 1- and 3-year survivals of 57 and 26%, respectively. Patients presenting before age 60 years survived nearly twice as long as older patients did. Stage also influenced prognosis, whereas the histologic subtype of the tumors and the location within the pancreas correlated only weakly with survival.

Observer variation in the diagnosis of follicular variant of papillary thyroid carcinoma

The histopathologic diagnosis of follicular variant of papillary thyroid carcinoma (FVPCA) can be difficult. Recent reports have suggested that this neoplasm may be frequently overdiagnosed by pathologists. We examined the observer variation in the diagnosis of FVPCA in 87 tumors by 10 experienced thyroid pathologists. The criteria that the reviewers considered most helpful for making a diagnosis of FVPCA were also assessed. A concordant diagnosis of FVPCA was made by all 10 reviewers with a cumulative frequency of 39%. In this series, 24.1% of the patients had metastatic disease (n = 21). In the cases with metastatic disease, a diagnosis of FVPCA was made by all 10 reviewers with a cumulative frequency of 66.7%, and 7 of the reviewers made a diagnosis of FVPCA with a cumulative frequency of 100%. The most important criteria used to diagnose FVPCA included the presence of cytoplasmic invaginations into the nucleus (pseudo-inclusions), abundant nuclear grooves, and ground glass nuclei. These results suggest that although the diagnosis of FVPCA is variable even among experienced thyroid pathologists, most reviewers agreed on this diagnosis for patients with metastatic disease. The use of well-defined histopathologic features should improve the consistency in diagnosing FVPCA. Since most cases with metastatic disease had obvious invasion, caution should be used in making a diagnosis of FVPCA in the absence of the major histopathologic features or clear-cut invasive growth.

Localization of factor Viii-related antigen in vascular endothelial cells using an immunoperoxidase method

Using an immunoperoxidase method, factor VIII-related antigen was localized in vascular endothelial cells. This method provides a marker for endothelial cells at the tissue level and may be used to confirm the vascular nature of a variety of hyperplastic and neoplastic lesions of skin, soft tissues, and other locations.