Well-differentiated papillary mesothelioma of the female peritoneum: a clinicopathologic study of 26 cases

Well-differentiated papillary mesothelioma (WDPM) is an uncommon mesothelial tumor that occurs in the peritoneum of women over a wide age range. Although considered a tumor of uncertain malignant potential, information about its biological behavior is still limited. In this study, we present the clinicopathologic features of 26 cases of WDPM of the female peritoneum seen in our institution over a 20-year period (1990 to 2010). Clinical information and pathology material were reviewed in all cases. Patients ranged in age from 23 to 75 years (median, 47 y; mean, 48.6 y). There was no history of asbestos exposure in any of our cases. Ten patients had undergone surgery previously, and 6 had a history of endometriosis. In 24 patients, the WDPM was an incidental finding during surgery for a benign or malignant lesion. Only 2 patients presented with symptoms: 1 with an acute abdomen and the other with chronic pelvic pain. The former had developed a small hemoperitoneum because of bleeding of 1 of the lesions of WDPM, whereas the latter had a 2-cm WDPM involving the distal fallopian tube. The lesions were single or multiple (13 cases each) and ranged in size from 0.1 cm to 2 cm. The following sites were involved: abdominal or pelvic peritoneum not otherwise specified (10 cases), omentum (7 cases), cul-de-sac (6 cases), colonic serosa (4 cases), small bowel mesentery (2 cases), uterine serosa (2 cases), stomach serosa (1 case), large bowel mesentery (1 case), fallopian tube (1 case), ovary (1 case), and inguinal hernia (1 case). In all cases the lesions were excised. Microscopically, all of our cases had the typical features described for WDPM (ie, a papillary architecture that may be accompanied by glandular/tubular patterns, nests of cells and individual cells, bland mesothelial cells, absent or rare mitotic figures). The initial diagnosis in our cases was variable, including WDPM, mesothelial hyperplasia, malignant mesothelioma, serous tumor of low malignant potential of the peritoneum, papillary endosalpingiosis, and chronic xanthogranulomatous salpingiosis. Follow-up was obtained for 25 patients, and it ranged from 4 to 192 months (mean, 47.5 mo; median, 32 mo); 22 patients are alive with no evidence of WDPM after a follow-up that ranged from 5 to 144 months. One of these patients experienced recurrence of WDPM 46.5 months after initial diagnosis. In this patient, WDPM was an incidental finding during a total abdominal hysterectomy and bilateral salpingo-oophorectomy for serous cystadenofibroma. The recurrence was also an incidental finding during a colectomy for colonic adenocarcinoma. This patient is alive with no other recurrences 73 months after initial diagnosis and 36 months after diagnosis of the recurrence. Three patients died of other causes: pancreatic cancer at 4 months and 12 months and leukemia at 192 months. Recognition of the histologic features of WDPM and proper clinical correlation allow for the correct diagnosis of this entity. If necessary, immunohistochemical studies such as calretinin and keratin 5/6 facilitate the recognition of the mesothelial nature of this neoplasm. Although no patient died of disease in this series, follow-up of patients with this diagnosis is warranted on the basis of possible recurrences or misdiagnosis of an undersampled malignant mesothelioma.     

Benign multicystic mesothelioma with concurrent colonic adenocarcinoma: a report of two cases

Benign multicystic mesothelioma (BMM) is a rare tumoral lesion of the peritoneum often discovered incidentally upon surgery, laparoscopy, or radiographical imaging in females of childbearing age. The etiology and question as to whether these lesions occur via a neoplastic or reactive process still remain unknown. In this report, we present two cases of BMM detected in females with concurrent colonic adenocarcinoma arising in the ileocecal region. The tumors were present in the serosa surrounding the colonic adenocarcinoma in one case, and in the omentum in the other case, which grossly mimicked peritoneal seeding of carcinoma. An immunohistochemical analysis revealed that the cells lining the cystic spaces in both lesions were positive for keratin and calretinin, confirming their mesothelial origin. To the best of our knowledge, these cases represent the first documented examples of multicystic mesothelioma concurrent with colonic adenocarcinoma.     

Micronodular thymoma with lymphoid B-cell hyperplasia: clinicopathologic and immunohistochemical study of eighteen cases of a distinctive morphologic variant of thymic epithelial neoplasm.

We describe 18 cases of a distinctive morphologic variant of primary thymic epithelial neoplasm characterized by a micronodular growth pattern associated with florid lymphoid follicular hyperplasia of the stroma. The tumors occurred in seven women and 11 men aged 41 to 76 years (mean, 58 years). All cases were asymptomatic and discovered incidentally on routine chest radiograph or during coronary artery bypass surgery. The tumors measured from 3 to 10 cm in greatest dimension and were well circumscribed and encapsulated. In seven cases, the lesions were grossly described as cystic or partially cystic masses. Histologically, they were characterized by a proliferation of small tumor nodules separated by abundant lymphoid stroma with prominent germinal centers. The nodules were composed of spindle cells containing oval nuclei devoid of atypia or mitotic activity. Immunohistochemical studies showed strong positivity of the spindle tumor cells for CAM 5.2 and broad spectrum keratin antibodies. The surrounding lymphoid cell population was strongly positive for LCA and L26 and showed a polyclonal pattern of staining for kappa and lambda. Stains for UCHL-1, CD1a, CD3, CD5, and CD99 were negative in the stromal lymphoid cell population. The tumor in one of the patients was associated with active pulmonary tuberculosis, and in another with anemia and splenomegaly of unknown etiology. None of the patients had clinical signs or history of myasthenia gravis or other autoimmune disorders. The present cases are interpreted as an unusual morphologic variant of spindle cell thymoma with prominent B-cell lymphoid hyperplasia. The possible significance of this phenomenon is discussed.     

Surgical treatment of large pericardial effusions. Etiology and long-term survival

From 1977 to 1988 60 patients were treated for large pericardial effusion. The operation consisted of a small left anterior thoracotomy with formation of a pericardial window. In 28 patients (47%) the etiology was a malignant disease. Eight patients (29%) had malignant cells in the pericardial fluid and 23 patients (82%) had metastases to the pericardium. Seven patients (12%) had purulent pericarditis; in 4 cases Staphylococcus was found. Of the remaining 25 patients, the etiology remained unknown in 13. The 5-year survival rate was 60% among patients with nonmalignant effusions. In patients with malignant effusions only 20% were alive after 2 years. There were no deaths related to the operation. We conclude that large pericardial effusions of unknown etiology can be safely treated with a small left anterior thoracotomy. This access gives optimal possibilities for rapid diagnosis and treatment.     

Proliferative fasciitis and myositis of childhood.

Eleven cases of proliferative fasciitis and myositis in children, ages 2.5 months to 13 years, are presented. Eight lesions averaging 2.3 cm in size occurred in the extremities, two in the head and neck region and one on the chest wall. Like proliferative fasciitis and myositis in adults, these lesions consisted of admixtures of large polygonal to spindled, ganglion-cell-like fibroblasts with vesicular nuclei and prominent inclusion-like nucleoli. Seven of 11 lesions were initially diagnosed as sarcomas, most commonly rhabdomyosarcoma. Four patients were treated by wide excision (three with regional lymphadenectomy), three received chemotherapy, and one was given radiation therapy. There were some histologic differences from adult-type proliferative fasciitis and myositis. The childhood lesions were generally well circumscribed, lobulated, extremely cellular with less collagen production, and often associated with acute inflammation and microscopic foci of necrosis. Immunohistochemical comparison with adult proliferative fasciitis and myositis showed similar immuneprofiles; the ganglion-like cells stained for vimentin and actin and focally with KP1, suggesting myofibroblastic and histiocytic features. None of the lesions stained for keratin, desmin, or S-100 protein. Ultrastructural examination of two cases revealed cells with a constellation of fibroblastic, myofibroblastic, and histiocytic features. Follow-up of seven patients, averaging 58 months from diagnosis, confirmed that all are alive and well. Recognition of this cellular variant of proliferative fasciitis and myositis is important to prevent misdiagnosis as a sarcoma and unnecessary, excessive therapy.     

In vivo protein markers of human peritoneal mesothelial cells: do they differ according to their anatomical sites?

OBJECTIVE: To highlight the in vivo protein markers in human peritoneal mesothelial cells according to their anatomical distribution and their interest in theories of peritoneal repair. DESIGN: Clinical laboratory study. SETTING: University Hospital, France. PATIENTS: Sampling of mesothelial cells during 8 laparotomies by impression smears. MAIN OUTCOME MEASURES: Immunochemical semiquantitative measures of proteins. RESULTS: There were uniform ratios of protein markers among the whole peritoneal mesothelial cell population, whatever their anatomical origin (liver, stomach, omentum, small bowel, and abdominal wall). CONCLUSION: This is consistent with the surrounding uninjured mesothelial cells or the exfoliated mesothelial cells, or both, having a role in postoperative peritoneal mesothelial repair.     

Solitary fibrous tumor of the upper respiratory tract. A report of six cases.

We report six cases of a neoplasm that arose in the upper respiratory tract and had a histological appearance indistinguishable from that of solitary fibrous tumor of the pleura (SFT, so-called fibrous mesothelioma). The patients were adults who presented with nasal obstruction. The lesions lacked the characteristic features of other recognized neoplasms that occur in this region. The tumor cells were immunoreactive for vimentin but not for keratin. The occurrence of SFT in this location further supports the argument that SFT is a tumor of mesenchymal and not mesothelial origin. None of the tumors in this series had the histologic features of malignancy described for SFT in other locations, and there was no aggressive behavior in limited follow-up. Until more cases of SFT in unusual locations have been studied, we recommend that the same criteria used for assessing aggressiveness in SFT of the pleura be applied to them.     

Regeneration of pericardial tissue on absorbable polymer patches implanted into the pericardial sac. An immunohistochemical, ultrastructural and biochemical study in the sheep.

A new absorbable polymer prepared from polyhydroxybutyrate (PHB) was inserted as a pericardial patch in sheep to serve as a temporary scaffold for regeneration of pericardial tissue. Postoperative adhesions were rare or absent. The present study focuses on characterization of the regenerated surface cells. The luminal surface of the regenerated tissue was covered with a complete layer of mesothelium-like cells which at light and scanning electron microscopy resembled those in native pericardium. Immunohistochemical stainings for cytokeratin and thrombomodulin were positive in these cells. Heparan sulfate proteoglycan was found in a basement-membrane-like structure beneath the surface cells, as in the normal pericardium. Transmission electron microscopy of the regenerated surface revealed cells with the characteristics of mesothelium. Prostacyclin production in the regenerated tissue was similar to that in native pericardium. The results indicate regeneration of a mesothelial layer with many of the important functions of native mesothelial cells. This may explain the presently and previously observed prevention of pericardial adhesions after cardiac surgery in this field. Clinical testing of PHB patches as pericardial substitutes is warranted in cardiac surgery when pericardial closure is desired.     

The Ionescu-Shiley valve: a solution for the small aortic root

Valve replacement in patients with a small aortic anulus can cause difficult technical problems or leave the patient with a significant residual transvalvular gradient. Between August, 1977, and June, 1983, 35 patients with a small aortic root (21 mm or less) underwent aortic valve replacement with Ionescu-Shiley pericardial xenograft valves. They ranged in age from 29 to 76 years (mean 52.8 years) and in weight from 64 to 91 kg (mean 76.3 +/- 3.6 kg). Preoperatively, 26 patients were in New York Heart Association Functional Class III-IV. The valve sizes used were 17 mm in three cases, 19 mm in 16 cases, and 21 mm in 16 cases. There were four hospital deaths (11.4%) resulting from sepsis or low cardiac output. There were no late deaths. Cumulative duration of follow-up was 819.4 patient-months. Twenty-four (78%) of the 31 surviving patients are asymptomatic. Up to the time of review, there have been no episodes of thromboembolism, infective endocarditis, perivalvular leak, valve thrombosis, or primary tissue valve failure. Fifteen patients were hemodynamically evaluated 2 to 47 months (mean 14.3 months) after operation. The average resting transvalvular gradients for 19 and 21 mm valves were 15.1 and 10.8 mm Hg, respectively. Our experience suggests that the Ionescu-Shiley pericardial xenograft valve is a valid alternative in the surgical treatment of patients with a small aortic root.     

Aortic valve replacement with pericardial valves in patients with small aortic roots. Clinical results in a consecutive series of patients receiving 19 and 21 mm prostheses

OBJECTIVE: To determine how second generation pericardial valves perform in patients with small aortic roots. DESIGN: Ninety patients who underwent isolated aortic valve replacement (AVR) with 19 or 21 mm Mitroflow or Carpentier-Edwards (Perimount) valves between 1989 and 1996 were studied. Mean age was 78 years. Concomitant coronary bypass surgery was performed in 41%. RESULTS: Thirty-day mortality was 5.6%. Ninety-seven percent had acceptable transprosthetic mean pressure gradients (25 mmHg or less) 1 week after surgery. Follow-up was 100% complete and 76% of the patients were alive after a mean of 5 years. There was no structural valve failure or valve thrombosis. One patient required reoperation for perivalvular leak. Four patients had transient ischemic attacks and seven had strokes. These figures are, however, within the expected range for the age. CONCLUSION: Second generation pericardial valves perform well in elderly patients with small aortic roots. Postoperative hemodynamics are acceptable, valve durability of up to 8 years adequate, and the clinical results good, considering the age of the patients.     

Clinical experience with subxyphoid pericardial decompression

Between 1971 and 1981, 108 patients with pericardial effusion were treated by subxyphoid pericardial decompression. 68 patients (63%) had local anesthesia, while general anesthesia was used in 40 (37%). The total group included nonspecific (viral) pericarditis in 35 patients (32.4%), uremic pericarditis in 30 (27.8%); and 20 patients (18.5%) with a malignant etiology, traumatic in ten patients (9.3%), six patients (5.6%) following radiation for malignant disease, and seven patients (6.5%) due to other causes. Echocardiography was diagnostic in all cases. Acute cardiac tamponade necessitated pericardiocentesis as an initial procedure in seven patients (6.5%). Subxyphoid pericardial decompression included drainage of the pericardial fluid and performance of a 5 X 5 cm pericardial window and biopsy of all patients. There were two (1.8%) operative deaths in the general anesthesia group but none in the local anesthesia group. There were no major complication in the local anesthesia group, but one patient in the general anesthesia group, who was severely hypertensive preoperatively, developed hemiplegia on the left side. There were five recurrences (4.6%) requiring total pericardiectomy at a later date. Subxyphoid pericardial decompression under local anesthesia was seen to be a safe and effective procedure for primary decompression and diagnosis of acute or chronic pericardial effusion.     

HEPATIC CAVERNOUS HAEMANGIOMA: A 10 YEAR REVIEW

Between January 1981 and July 1991, 61 patients with hepatic haemangiomata were examined at Westmead Hospital. There were 14 males (22%) and 47 females (78%). The age range was 26–85 years with a median of 49 years. Forty-one had abdominal symptoms but these could be attributed to a haemangioma in only seven cases. There was at least one subcapsular lesion in 17 (28%). Six of the seven symptomatic lesions were subcapsular and five of these were giant haemangiomata (i.e. more than 4 cm in greatest diameter). One large symptomatic lesion was intrahepatic. No association was observed between hepatic haemangiomata and other hepatic or extrahepatic diseases. Haemangiomata were resected from six patients, four of whom were symptomatic. Symptoms improved in all four but did not resolve completely in any. Follow-up ranged from nil in five patients to 108 months in one. The median follow-up was 12 months after initial diagnosis. Ten patients showed evidence of change in their lesions or symptoms while under observation. Only three had worsening symptoms or suspected change in size of a haemangioma. This study highlights the benign, static nature of most hepatic haemangiomata. When this lesion is suspected, the diagnosis should be confirmed with ultrasound (US) and labelled red blood cell scanning (RBCS). Referral for evaluation by a specialist hepatobiliary surgery unit is necessary when symptoms are intolerable, increasing size is definitely demonstrated or the diagnosis is uncertain and cannot be established without specialized investigations. Bleeding into or from these lesions is rare.     

Hepatic cavernous haemangioma: a 10 year review.

Between January 1981 and July 1991, 61 patients with hepatic haemangiomata were examined at Westmead Hospital. There were 14 males (22%) and 47 females (78%). The age range was 26-85 years with a median of 49 years. Forty-one had abdominal symptoms but these could be attributed to a haemangioma in only seven cases. There was at least one subcapsular lesion in 17 (28%). Six of the seven symptomatic lesions were subcapsular and five of these were giant haemangiomata (i.e. more than 4 cm in greatest diameter). One large symptomatic lesion was intrahepatic. No association was observed between hepatic haemangiomata and other hepatic or extrahepatic diseases. Haemangiomata were resected from six patients, four of whom were symptomatic. Symptoms improved in all four but did not resolve completely in any. Follow-up ranged from nil in five patients to 108 months in one. The median follow-up was 12 months after initial diagnosis. Ten patients showed evidence of change in their lesions or symptoms while under observation. Only three had worsening symptoms or suspected change in size of a haemangioma. This study highlights the benign, static nature of most hepatic haemangiomata. When this lesion is suspected, the diagnosis should be confirmed with ultrasound (US) and labelled red blood cell scanning (RBCS). Referral for evaluation by a specialist hepatobiliary surgery unit is necessary when symptoms are intolerable, increasing size is definitely demonstrated or the diagnosis is uncertain and cannot be established without specialized investigations. Bleeding into or from these lesions is rare.     

Primary ovarian small cell carcinoma of pulmonary type. A clinicopathologic, immunohistologic, and flow cytometric analysis of 11 cases.

Eleven primary ovarian tumors that resembled small cell carcinoma of the lung are reported. They occurred in women 28-85 (mean 59) years of age, most of whom presented with abdominal swelling. Six of the tumors were unilateral and five bilateral; seven had spread beyond the ovary. The tumors ranged from 4.5 to 26 (mean 13.5) cm in greatest dimension and were mostly solid, with a variable minor cystic component. Microscopic examination showed small to medium-sized round to spindle-shaped cells with scanty cytoplasm, hyperchromatic nuclei, and inconspicuous nucleoli growing in sheets, closely packed nests, and occasionally islands and trabeculae. A component of endometrioid carcinoma was present in four tumors, another tumor showed squamous differentiation, another contained a cyst lined by atypical mucinous cells, and two others were associated with a Brenner tumor. Argyrophil granules were present focally in two of six tumors appropriately stained. Immunohistochemical staining was performed in nine cases: in six there was staining of the small cell component for keratin, in five for epithelial membrane antigen, in seven for neuron-specific enolase, in two for chromogranin, and in one for Leu-7. Vimentin staining was not observed. Flow cytometry was performed on eight tumors: five were aneuploid and three diploid. Five of seven patients with long-term follow-up died of, or with, disease at 1-13 (mean 8) months, one died after an unknown interval, and one was alive at 7.5 years. Two other patients had recurrent or residual disease at 6 and 8 months.     

Usual and unusual locations of intrathoracic mesothelial cysts. Is endoscopic resection always possible?

OBJECTIVE: Mesothelial intrathoracic cysts are congenital lesions classically located in the anterior cardiophrenic angle (pleuro-pericardial cysts). Locations elsewhere in the thorax are infrequent. The aim of the study was to describe a 10-year, single-institution experience with endoscopic management of mesothelial cysts by video-assisted thoracoscopy (VT) or video-assisted mediastinoscopy (VM), regardless of their location. METHODS: From January 1992 to December 2002, 13 patients (four males and nine females, mean age 49.9 years, range 22-75) underwent surgery for a mesothelial cyst. Information on past history, clinical and radiological presentation, indications for surgery, the surgical procedure and postoperative outcome were collected retrospectively and inserted in a dedicated database. A follow-up visit was performed on December 2002 in all of the patients. RESULTS: In five patients the cyst was in the right cardio-phrenic angle, in three cases it was in the left cardiophrenic angle. Five cysts were located in the mediastinum (right paratracheal space in two cases, anterior mediastinum in one case, paravertebral mediastinum in two cases). Mean lesion diameter was 7.5 cm (+/-4) x 5 cm (+/-2). Cyst density ranged between 1 and 10 Hounsfield units (HU) in 11 patients. It was respectively 38 and 52 UH in the other two patients. All patients were classed ASA 1 or 2 according to the guidelines of the American Society of Anesthesiologists (ASA). Indications for surgery included the presence of symptoms, uncertain diagnosis, practice of a particular sport or professional activity, and radiological evidence of compression of the superior vena cava (namely for the two paratracheal lesions). Eleven patients were operated on by VT. Two patients with a right paratracheal lesions were operated on by VM. Mean operating time was 60+/-14 min (range 45-80). No postoperative complications were recorded. The mean postoperative stay was 4.3+/-1.2 days (5 days for VT and 2.5 days for VM). Pathology studies confirmed the diagnosis of mesothelial cyst in all cases. CONCLUSIONS: Mesothelial cysts have a heterogeneous distribution within the thorax, and nearly 40% are located elsewhere than in the cardiophrenic angle. Endoscopic resection by VT or VM can be proposed as the treatment of choice even for mesothelial cysts in unusual locations.     

Reactive angioendotheliomatosis: a study of 15 cases demonstrating a wide clinicopathologic spectrum

Reactive angioendotheliomatosis (RAE) is a rare condition characterized by cutaneous vascular proliferation that usually occurs in patients with diverse types of coexistent systemic disease. Although intravascular proliferation of endothelial cells has been considered to be the key histologic feature in RAE, other patterns of vascular proliferation have also been described. We reviewed the clinicopathologic features in 15 cases of RAE. The study group comprised eight males and seven females with an age range of 47-88 years (median 65 years). Eleven patients had coexistent systemic disease: renal disease (six patients, including three post renal transplantation); valvular cardiac disease (two patients); one patient each had alcoholic cirrhosis, glioblastoma multiforme (on chemotherapy), and rheumatoid arthritis/polymyalgia rheumatica. Six patients were iatrogenically immunosuppressed at the onset of the skin lesions. The clinical appearance included multiple erythematous macules, plaques, tumors, and ulcerated lesions, with a wide distribution but a propensity to involve limbs. Lesions had been present for 1 month to 4 years (median 4 months). Lesions resolved in four cases, improved in two cases, remained static in one case, and progressed in four cases. Two cases were recent and follow-up was not available in two other cases. Three patients died of their coexistent systemic disease with resolution, improvement, and progression of lesions, respectively. All lesions were characterized histologically by a proliferation of capillaries in the dermis, with variably diffuse (seven cases), lobular (six cases), or mixed lobular and diffuse patterns (two cases). There was marked intercase and intracase heterogeneity in histologic features. Common features included fibrin microthrombi (nine cases), reactive (fasciitis-like) dermal alterations (seven cases), and foci of epithelioid endothelium (four cases). Four of 10 cases tested showed positive immunohistochemical staining for HHV-8 latent nuclear antigen in lesional endothelial cell nuclei. This study suggests that RAE has a broader clinicopathologic spectrum than previously described. The pathogenesis of this rare disorder is unknown, but it is likely that immunologic factors play a role.     

Benign mesothelial cells in mediastinal lymph nodes.

Inclusions of benign tissues in lymph nodes are most often aberrant glandular tissue, including endosalpingiosis, the thyroid, parotid, breast, and pancreas. Nonglandular inclusions are rare and include nevus cells and decidua. Mesothelial cells in lymph nodes are exceedingly rare; only eight cases have been reported in mediastinal lymph nodes and three cases in abdominal lymph nodes. The incidence of benign mesothelial cells in mediastinal lymph nodes in patients with a history of pericarditis or pleuritis is reported in this study. A retrospective search showed eight cases with removal of mediastinal lymph nodes in the absence of neoplasm. Hematoxylin and eosin-stained sections were examined in all cases. Immunohistochemical stains for CAM 5.2 were performed in all cases, and stains for AE1/AE3, Ber-EP4, carcinoembryonic antigen, Leu-M1, B72.3, and S-100 were performed in one case. CAM 5.2-positive cells with features of mesothelial cells were present in five of eight cases. In all cases, the cells were present in nodal sinuses and appeared as single cells or small clusters. The cells were missed on routine hematoxylin and eosin sections in all cases but one, in which they were numerous and mimicked metastatic carcinoma. Malignancy was not found in any of the cases preoperatively, at the time of surgery, or during the follow-up period. Benign mesothelial cells may embolize to regional lymph nodes in pleuritis or pericarditis. In most cases, these cells are few and undetectable on routine sections. Rarely, hyperplastic mesothelial cells may be present and must be distinguished from metastatic carcinoma, mesothelioma, and melanoma.     

Primary thymic epithelial neoplasms in children

Primary epithelial neoplasms of the anterior mediastinum in children are very rare. We have studied 10 cases of thymic epithelial neoplasms in children aged 16 years or less and correlated their histologic features with the clinical outcome. The patients' ages ranged from one to 16 years (mean: 10.2); with a male:female ratio of 1.5:1. Nine patients had symptoms attributable to their tumors; one was asymptomatic. Four patients presented in clinical stage I, one in stage IIb, and five in stage IVb. Histologically, the tumors comprised a heterogenous group displaying a range of morphologic appearances: one tumor had the classic features of lymphocyte-rich thymoma of the adult; four were of the lymphocyte-rich type with associated unusual stromal features; two were spindle cell thymomas with cytologic and architectural atypia; and three displayed obvious cytologic features of malignancy (i.e., thymic carcinoma); two in the last group showed features of small cell carcinoma, and the other was an undifferentiated/anaplastic carcinoma. The epithelial nature of the tumors was supported in six cases by positive staining of the tumor cells with keratin antibodies and in two cases by electron microscopic demonstration of desmosomes and intracytoplasmic bundles of tonofilaments within the tumor cells. The prognosis for these patients correlated well with the degree of atypicality exhibited by the epithelial components; it was very poor in patients with small cell and undifferentiated/anaplastic carcinoma (8 months average survival), better for those with atypical spindle cell thymomas (multiple recurrences and metastases but no fatalities over a 15- to 72-month period), and best in those with lymphocyte-rich thymomas without cytologic atypia (no recurrences or metastases over an 8-month to 3-year follow-up).     

Aneurysmal bone cyst: clinicopathologic features and treatment of ten cases involving the hand

Ten cases of aneurysmal bone cyst in the hand were identified among 208 such lesions in our institutional files. The patients (six women and four men) had a mean age of 27.3 years. Two patients had open physes. Seven lesions were in the metacarpals. Radiographic examination showed that in all cases the lesion was both expansile and completely lucent. There were no recurrences in the three patients treated by complete excision and bone grafting. Curettage and bone grafting in seven cases was associated with four recurrences. Three of these four local recurrences were treated successfully with curettage procedures. Treatment of aneurysmal bone cysts of the small bones of the hand requires either thorough exteriorization, curettage, and bone grafting or excision and bone grafting.     

Epithelioid hemangioma versus Kimura's disease. A comparative clinicopathologic study

A clinicopathologic and immunohistochemical study of eight cases of epithelioid hemangioma and 11 cases of Kimura's disease was performed. Patients with epithelioid hemangioma (EH) ranged in age from 15 to 56 years (mean, 37 years) and had small papular or nodular lesions occurring most often on the face and scalp. The lesions were less than 2.0 cm in diameter. There were irregularly hypertrophic vascular structures with swollen endothelial cells and of a variable lymphoid infiltrate with eosinophils. The clustering of small vessels around the arteries or veins was another distinctive feature. Arteriovenous shunts were evident in three lesions. Patients with Kimura's disease, however, presented large solitary or multiple nodules occurring most commonly in the periauricular region. Six patients had a history of regional lymphadenopathy; three patients had eosinophilia of the peripheral blood. Microscopically, the distinctive features were of numerous lymphoid follicles and a salient eosinophilic infiltrate. These lymphoid follicles possessed distinct germinal centers and contained an increased number of dendritic cells. Although some small-vessel proliferation was noted, it was not as distinctive as for patients with epithelioid hemangioma. We conclude from this study that the two conditions should be considered different entities.