Botryoid odontogenic cyst. Exploration of proliferative activity, apoptosis and expression of TP53 and BCL2 compared to the histologically identical lateral periodontal and gingival cysts.

The botryoid odontogenic cyst (BOC) is a rare, locally more aggressive variant of the usually indolent lateral periodontal cyst (LPC) and gingival cyst (GC). A recent case of BOC provided an opportunity for an exploratory study on the causes of its more aggressive behavior. The limited objective was to see if the BOC was sufficiently different from the other cysts to warrant an investment in a large study. Sections of neutral buffered formalin fixed, paraffin-embedded tissues from the BOC and archival specimens of four GCs, four LPCs and three odontogenic keratocysts (OKCs) were stained using immunohistochemistry for Ki-67, a marker of proliferating cells, caspase-3, a marker of cells undergoing apoptosis, tumor suppressor p53, and the apoptosis inhibitor BCL2. The mean labeling index (LI) of immunoreactive cyst epithelial cells was computed for each antibody and type of cyst. Compared to the LPCs and GCs, the BOC exhibited a moderately larger Ki-67/caspase-3 LI difference, which indicates that the BOC had a net higher rate of growth. We found a much higher level of LI, therefore likely dysregulation of p53. We also found a much higher LI of BCL2. The LIs of p53 and BCL2 in the BOC were similar to and more than twice that of the OKCs, respectively. Although meaningful statistical analysis was precluded by our use of only one case of BOC and a small number of the other cysts, the high p53 and very high BCL2 labeling indices of the BOC offer a potential explanation for its reportedly more aggressive behavior that clearly is worthy of further investigation.

Retroperitoneal leiomyomas: a clinicopathologic and immunohistochemical study of 56 cases with a comparison to retroperitoneal leiomyosarcomas.

Most retroperitoneal smooth muscle tumors are believed to be malignant, and leiomyomas are considered very rare. This study was undertaken to determine the clinicopathologic features and long-term follow-up of 56 tumors diagnosed as retroperitoneal leiomyomas (LM) or smooth muscle tumors with an uncertain malignant potential (SMTUMP) in an effort to correlate their behavior and clinicopathologic features. These tumors were compared with a series of 11 cases of retroperitoneal leiomyosarcomas (excluding gastrointestinal stromal tumors). Histologic slides and immunohistochemistry for SMA, desmin, S-100 protein, HMB45, CD34, C-KIT, estrogen (ER) and progesterone (PR) receptor proteins, and MIB-1 were analyzed. All tumors diagnosed as LM and all but one SMTUMP were well-differentiated smooth muscle tumors that lacked atypia and coagulative necrosis. There was <1 mitosis per 50 high power field (HPF) in 38 tumors; no tumor had >3 mitoses/50 HPF. Most tumors had a striking resemblance to uterine smooth muscle tumors with common hyaline change and trabecular patterns. There were 51 females and 5 males ranging in age from 25 to 79 years (mean 45 years, median 43 years). These tumors were typically large, with a mean size of 16.2 cm and weight of 1600 g. Immunohistochemically, all 35 tumors studied were positive for alpha-SMA, 30 of 35 tumors were positive for desmin, and all were negative for CD117, S100 protein, and HMB45 and all but one for CD34. Steroid receptors were commonly present: ER in 20 of 29 cases and PR in 26 of 31 cases in the tumors of female patients. MIB-1 score was <2% in all of 28 cases. Long-term follow-up (mean 140 months) did not reveal metastases, but two patients had local recurrence; however, neither patient with recurrence demonstrated disease progression in follow-up. By contrast, all 11 leiomyosarcomas had at least mild atypia, and all were ER and PR negative. All cases had MIB-1-positive nuclei, but only four had >10% nuclei positive. Four patients died of disease, four were alive with recurrence, and three had no evidence of disease. A group of benign leiomyomas can be identified among retroperitoneal smooth muscle tumors. Most of these tumors resemble uterine leiomyomas by histology and positive hormone receptors, and they seem to have a good long-term prognosis with a small potential for local recurrence.

A clinicopathologic and immunohistochemical study of 35 anaplastic carcinomas of the pancreas with a review of the literature.

Anaplastic pancreatic carcinomas are rare tumors, frequently displaying a variety of growth patterns. The literature lacks a comprehensive study of this tumor. Thirty-five cases of anaplastic carcinoma of the pancreas diagnosed between 1955 and 1997 were retrieved from the Endocrine Registry at the Armed Forces Institute of Pathology. Histology, immunophenotype, molecular analysis, and patient follow-up were analyzed. The tumors of 10 women and 25 men, aged 34 to 85 years (mean age at presentation, 62.5 years), were studied. Patients had vague symptoms (weight loss, pain, and fatigue, nausea, or vomiting), lasting an average of 13.2 weeks. The tumors, of an average size of 9.2 cm, were usually in the head or tail of the pancreas. The tumors were widely infiltrative, histomorphologically separated into predominantly large, pleomorphic cell, or spindle cell groups. Tumor phagocytosis and necrosis were noted. Immunohistochemical studies confirmed an epithelial origin with at least one epithelial marker in 78% of the tumors. K-ras mutations by sequence analysis were found in eight of 12 cases tested. Surgical biopsy/excision was used in all patients. Twenty-nine of 35 patients died of disease (average, 5.2 months), three died with no evidence of disease (average, 56.9 months), and three patients were alive at last follow-up (average, 94.0 months), one with residual disease. There was no statistically significant difference in survival between patients with and without a K-ras mutation. Anaplastic carcinoma of the pancreas usually occurs in the head of the pancreas in older men. The epithelial nature of the pleomorphic cells (giant or spindled) can usually be documented. Patients with K-ras mutations have a shorter survival time, even though the overall prognosis for all anaplastic carcinomas is fatal (93% fatality; average survival, 448 days). Ann Diagn Pathol 5: 129-140, 2001. This is a US government work. There are no restriction on its use.

A clinicopathologic study of minimally invasive follicular carcinoma of the thyroid gland with a review of the English literature.

BACKGROUND: The criteria for minimally invasive (low grade) follicular carcinoma of the thyroid (MI) remain controversial, often resulting in unnecessary treatment. METHODS: The records of 130 patients with minimally invasive (MI) follicular thyroid carcinoma were retrieved from the files of the Endocrine Tumor Registry of the Armed Forces Institute of Pathology. RESULTS: Ninety-five patients were confirmed to have MI based on the authors' criteria of small-to-medium vessel invasion, capsular invasion of up to full thickness, no parenchymal tumor extension, and no tumor necrosis (patients with oxyphilic tumors were excluded). The remaining 35 patients had tumors that were reclassified as "not low grade" based on large vessel invasion, extension into parenchyma, and tumor necrosis (oxyphilic cases excluded). The MI patients included 67 women and 28 men, ages 20-95 years (average, 42.0 years). Nearly all patients presented with a thyroid mass (n = 90 patients). The mean tumor size was 2.8 cm. Histologic features examined for tumor classification included cellularity, capsule nature, capsular invasion, vascular invasion, extension into parenchyma, cytoplasmic oxyphilia, mitotic activity, and necrosis. All patients were treated with surgical excision. Adjuvant radioactive iodine therapy was performed in 24 patients. Five patients developed recurrent disease: four were alive or had died without evidence of disease after additional treatment (mean, 18.1 years), and one patient died with disease (MI tumor) at 15.1 years. All of the remaining patients were disease free (mean follow-up, 16.5 years). CONCLUSIONS: There are reproducible histologic criteria to diagnose patients with MI follicular carcinoma. The overall excellent long term prognosis and a good patient outcome suggests that no additional surgery is necessary.

Tenascin expression in primary and recurrent breast carcinomas and the effect of tenascin on breast tumor cell cultures.

Tenascin is generally classified as an anti-adhesive protein. Many cells do not adhere to tenascin or if they adhere they do not spread. In this study we analysed the stromal expression of tenascin-C in primary, second primary and recurrent breast carcinomas and the ability of tenascin-C to stimulate the focal adhesion plaques in MDA-MB-435 breast carcinoma cell line. To assess the tenascin-C expression formalin-fixed, paraffin-embedded specimens of 20 specially selected breast carcinomas and their recurrences (14) or a second primary breast cancer of the same patient (6) were examined with immunohistochemical methods. We also studied the effect of tenascin-C on focal adhesion plaques added to MDA-MB-435 breast carcinoma cell line. During a median 2,9-year patient follow up 14 local recurrences and 6-second primary breast carcinomas developed in the 20 patients. In 3 cases a second recurrence occurred. The presence of tenascin in tumor cells, in the proliferating and some normal ducts, near to the tumor cell nests, in the stroma and in ductal carcinoma in situ component of the invasive carcinoma may suggest the role of tenascin played in tumor cell migration. Soluble tenascin added to the cell culture had minimal or no effect on focal adhesion plaques. Tenascin only seems not to be of prognostic value in predicting the local recurrence of breast cancer.

A clinicopathologic and immunohistochemical study of 22 intraductal papillary mucinous neoplasms of the pancreas, with a review of the literature.

Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas are rare lesions. We undertook this study to analyze these tumors by focusing on the diagnostic criteria and correlating the histologic features with clinical prognosis. Twenty-two cases of IPMN were retrieved from the Endocrine Tumor Registry of the Armed Forces Institute of Pathology. Blocks or unstained slides were available for histochemical and immunohistochemical studies (including proliferative markers and cell cycle regulators) and K-ras oncogene mutations in 15 cases. Patient follow-up was obtained in all of the cases. IPMN occurs in both genders with a slight male predominance, with a mean age at presentation of 64.4 years (range, 48-85 yr). The patients presented with abdominal pain. The neoplasms were radiologically and grossly cystic, usually (18 cases of 22) located in the head of the pancreas. Histologically, the tumors consisted of intraductal papillary proliferations protruding into and expanding the pancreatic ducts. Invasion into the surrounding pancreatic parenchyma was detected in 15 cases. Chronic pancreatitis was present in all of the cases. p27 immunoreactivity always exceeded the immunoreactivity of cyclin E. K-ras oncogene mutations were detected in two cases. Patients were treated with a complete surgical resection (n = 7) or a Whipple procedure (n = 13). Only 2 of 22 patients died of disease (3 died immediately postoperatively and 3 died of unrelated causes), whereas the remaining 14 patients were alive at last follow-up, without evidence of disease, an average of 58.2 months after initial presentation. IPMNs are rare, distinctive neoplasms, with complex intraductal papillae, that can be easily separated from in situ ductal adenocarcinoma and mucinous cystic neoplasms. The high ratio of p27 protein to cyclin E supports the excellent prognosis of these neoplasms, despite the presence of invasion and K-ras oncogene mutation.

A clinicopathologic and immunohistochemical study of ten pancreatic lymphangiomas and a review of the literature.

BACKGROUND: Pancreatic lymphangiomas are rare benign tumors, of which only a few cases have been reported in the literature. In this study, the authors present a series of primary pancreatic lymphangiomas. METHODS: Cases of nonepithelial pancreatic cystic tumors (lymphangiomas) diagnosed between 1966 and 1994 were retrieved from the Endocrine Pathology Registry of the Armed Forces Institute of Pathology. Histologic features (in 10 cases) as well as histochemical and immunohistochemical studies (in 6 cases) were reviewed. Long term patient follow-up data were obtained in 9 cases. RESULTS: The patients included 8 females and 2 males ages 2-61 years (mean age, 28.9 years) at initial presentation. The tumors were circumscribed and occurred predominantly (in 6 of 10 cases) in the tail of the pancreas. The multicystic, serous, or chylous fluid-filled cystic tumors ranged from 3 to 20 cm (average, 12.7 cm) in greatest dimension. Histologically, the tumors consisted of multilocular cystic spaces of various sizes, lined by endothelial cells. The stroma contained smooth muscle and mature lymphocytes. Immunohistochemistry determined the endothelial lining cells to be factor VIII-R antigen and CD31 positive (in all cases tested) but usually CD34 negative. All patients for whom follow-up data were obtained (n=9) were alive without evidence of disease an average of 7.2 years after initial diagnosis. CONCLUSIONS: Pancreatic lymphangiomas occur predominantly in females within a wide age range. Multilocular, fluid-filled cysts, with endothelial immunoreactivity for factor VIII-R antigen and CD31, are characteristic of these tumors. Complete surgical excision of these benign tumors resulted in excellent long term prognoses for all patients studied.