Carcinosarcomas of the lung: a clinicopathologic study of 66 patients

Carcinosarcoma is a malignant tumor having a mixture of carcinoma and sarcoma containing differentiated mesenchymal elements, such as malignant cartilage, bone, and skeletal muscle. These tumors have been linked histogenetically to pleomorphic carcinomas; it is unclear whether their clinical behavior is significantly different. To investigate this issue, we studied 66 cases of carcinosarcomas of the lung and compared them with cases from a previously published series of pleomorphic carcinomas. Carcinosarcomas show a male-to-female ratio of 7.25:1, with a mean and median age of 65 years. They most often present as solitary masses in the upper lobes and average 7 cm in diameter. Most (62%) were endobronchial or central tumors, whereas 38% were described as peripheral. The most frequent epithelial component was squamous cell carcinoma (46%), followed by adenocarcinoma (31%) and adenosquamous carcinoma (19%), whereas sarcomatous elements most frequently included rhabdomyosarcoma, chondrosarcoma, osteosarcoma, or combinations of these elements. Survival of patients with carcinosarcomas of lung was poor, with a 5-year survival rate of 21.3%. Of several clinical and pathologic parameters, only increased tumor size (with 6 cm as the optimal cutoff point) appeared to be related to reduced survival (p = 0.0195). In comparison with patients with pleomorphic carcinoma, patients with carcinosarcomas had no significant difference in the size of their tumors (p = 1.0), stage at presentation (p = 0.883), location in the lung (p = 0.073), or their overall survival (21.3% vs 15.0%) (p = 0.1038). A significantly greater proportion of patients with carcinosarcoma had squamous cell (p = 0.004) or adenosquamous (p = 0.016) carcinoma, whereas patients who had pleomorphic carcinoma showed a significantly greater frequency of adenocarcinoma (p = 0.029) and large cell carcinoma. The histologic differences between these two types of tumor suggest that they may be different entities with similar behavior, but additional studies are warranted to investigate this hypothesis.

Primary pulmonary ganglioneuroblastoma: a clinicopathologic and immunohistochemical study of two cases

We present two patients with primary ganglioneuroblastoma involving the bronchial wall. The first, a 38-year-old woman, presented with signs and symptoms suggestive of multiple endocrine neoplasia, including gastric ulceration and hypercalcemia. Chest radiographic studies revealed a 3-cm nodule in the hilus of the right lung and two less-pronounced lesions in the periphery of the right lung. The second, a 20-year-old asymptomatic woman, was evaluated for a solitary mass in the upper lobe of the left lung that was peribronchial and that impinged on the lumen of a bronchus. Grossly, both neoplasms extended from bronchi, were well-circumscribed, firm, tan or white, and homogeneous, and measured 5 x 5 cm and 3 x 3 cm, respectively. Histologically, both tumors were characterized by neuroblastoma with areas of neuropil and multifocal areas of ganglion cells. Immunohistochemical studies performed in one case showed focal staining for neurofilament protein and S-100 protein and diffuse staining for neuron-specific enolase. Follow-up information showed that one patient died a few days after admission to the hospital; the second patient has remained well and without evidence of recurrence or metastases 1 year after initial diagnosis. These two cases confirm that ganglioneuroblastoma can occur as a primary pulmonary tumor in adults, presumably arising from sympathetic ganglia of the bronchus.

Adenocarcinoma simulating mesothelioma: a clinicopathologic and immunohistochemical study of 29 cases

We report 29 cases of adenocarcinomas whose clinical, gross, and microscopic appearance resembled diffuse malignant pleural mesothelioma. Initial criteria for inclusion in the study included availability of an open pleural biopsy or decortication specimen and microscopic evidence of neutral (periodic acid-Schiff positive) mucin in the tumor. The median age of the patients was 63 years (range, 31 to 78 years), with a peak age in the seventh decade. There were 24 men and five women. Thirteen of them had a history of smoking; six (21%) had possible or definite occupational exposure to asbestos. Three (21%) of 14 lung specimens showed ferruginous bodies and two (14%) showed microscopic evidence of asbestosis. At least 25 patients had pleural effusion, most typically unilateral. Needle biopsy of pleura showed malignancy in 10 (77%) of 13 cases. Most (20 of 29) patients underwent pleural stripping. Radiotherapy and chemotherapy was each given to three patients without effect. Median survival by Kaplan-Meier estimate was 8 months, with an 18-month survival of 13%. Histologically, glands (23 cases), nests (13 cases), tubulopapillary arrays (12 cases), or sheets (eight cases) of tumor cells were found. Spindling of neoplastic cells was seen in 10% of cases. Three (21%) of 14 lung specimens showed a subpleural adenocarcinoma. Antibodies to polyclonal CEA, Ber-EP4, Leu-M1, and B72.3 were positive in 94%, 56%, 50%, and 44% of cases, respectively. All but one of the cases stained with two or more of the antibodies CEA, Ber-EP4, Leu-M1, or B72.3. This study indicates that adenocarcinomas simulating mesothelioma are aggressive variants of peripheral adenocarcinomas with a poor prognosis, that they can show pathological evidence of asbestos exposure in a subset of cases, and that immunohistochemical and histochemical stains are useful in their differential diagnosis with diffuse malignant mesotheliomas.

Primary pulmonary glomus tumor: a clinicopathologic and immunohistochemical study of two cases

We present two cases of glomus tumors arising within the lung parenchyma. The patients are a 40-year-old man and a 51-year-old man. Clinically, the two men were asymptomatic, and the pulmonary tumor was detected during a routine chest roentgenographic examination. Complete surgical resection of the pulmonary tumors was performed. Grossly, the tumors measured 1.1 and 1.5 cm. in greatest dimension; they were well circumscribed and subpleural. Neither tumor showed evidence of invasion of lung or pleura. Histologically, both tumors had pseudocapsules, lacked invasion of surrounding lung structures, and demonstrated the appearance of the solid/mucohyaline, or "glomus tumor proper" type of neoplasm. This included oval-to-round cells, with central uniform nuclei; variably eosinophilic-to-clear cytoplasm; and well-demarcated cell borders in close proximity to a rich vascular supply showing perivascular fibrosis. Immunohistochemically, both tumors showed diffuse, moderate-to-strong staining for vimentin, muscle-specific actin, and smooth muscle actin. One tumor also showed diffuse strong staining for desmin, whereas the other was negative. Follow-up information obtained from one of the patients revealed that he was alive and well 47 months after surgical resection. Our cases highlight the ubiquitous distribution of glomus tumor and its similar histologic appearance and immunohistochemical profile to soft tissue glomus tumors.

Pulmonary plasmacytomas: a clinicopathologic and immunohistochemical study of five cases

Five cases of primary plasmacytoma of the lung are presented. The patients were four men and one woman between the ages of 50 and 79 years (mean age, 57 years; median age, 54 years). Two patients presented with symptoms related to their tumor; these included cough, dyspnea, and hemoptysis. In two patients, the tumor presented as a hilar mass, whereas in the remaining three patients, the tumor was located intraparenchymally. Clinically, only one patient had a reported monoclonal gammopathy (IgG, kappa). Because of the proximal location of these tumors, three patients underwent pneumonectomy; one other underwent a lobectomy, and one had a segmental resection. Grossly, the tumors ranged from 2.5 to 8 cm in maximum diameter (mean, 4.4 cm); they were either peribronchial or involved a major bronchus. Histologically, they were characterized by sheets of plasma cells that were well differentiated in two cases and moderately differentiated in three. Amyloid was present in two cases. In four tumors, there was a monoclonal population of lambda light chain-bearing plasma cells, whereas in one, the plasma cells expressed a monoclonal kappa light chain. The tumor cells predominantly expressed IgG heavy chains in two cases. Peribronchial and mediastinal lymph nodes were involved in three cases. Follow-up information ranged from 4 days to 262 months (average, 115 months; median, 36 months). Two patients survived more than 20 years before dying of non-tumor-related causes. Two patients died 28 months and 4 days after surgery with concurrent tumor in liver and mediastinal and para-aortic lymph nodes. Comparing the present cases and those reported in the literature, we noted that the patients herein presented are, on average, older than those published previously. Combining our cases with 14 other verifiable, previously published cases, the overall 2- and 5-year survivals of pulmonary plasmacytomas are 66% and 40%, respectively. Patients with pulmonary plasmacytomas can have a long-term survival, as evidenced by two of our patients who survived 20 or more years.

Pulmonary lipomatosis: a variant of placental transmogrification

An unusual pulmonary lesion is presented. The patient is a 55-year-old white man with a 2-week history of pleuritic chest pain, shortness of breath, and bronchopneumonia. The patient had also a history of smoking and chronic cough for 12 years. Chest radiographic studies showed a 20-cm bulla in the left upper lobe. A left upper lobectomy was performed obtaining an almost completely collapsed lobe with destruction of the normal architecture by a meshwork of yellowish tissue. Histologically, there were strikingly papillary structures composed almost exclusively of mature adipose tissue with small collections of inflammatory cells. Minimal emphysema in the adjacent lung parenchyma was observed. The case herein presented most likely represents part of the spectrum of placental transmogrification or placentoid bullous lesions of the lung.

Pulmonary alveolar microlithiasis. A clinicopathologic and chemical analysis of seven cases

OBJECTIVE

To determine the clinical features and outcome of patients with pulmonary alveolar microlithiasis and to determine the chemical composition of the microliths.

CASE MATERIAL

We studied seven cases of pulmonary alveolar microlithiasis. The patients were six women and one man, aged 19 to 70 years (mean age 44.5 years). Clinically, five patients were known to have suffered from this condition for 5 to 41 years. One patient presented with shortness of breath, and another had a gradual decrease in exercise tolerance. None of the patients had a previous history of disturbances in metabolism or any other relevant medical condition. Reports on radiographic studies were available in six cases, and chest radiographs were available for review in the seventh case. They all showed diffuse bilateral pulmonary infiltrates. Open lung biopsies were performed in two patients, and autopsy lung material was reviewed in five patients.

RESULTS

Histologically, the lung showed the typical features of pulmonary alveolar microlithiasis, that is, presence of numerous microliths filling the alveolar spaces with either a normal or thickened fibrotic interstitium. Chemical analysis performed on the lung tissue of six of these patients revealed that the microliths consisted principally of calcium and phosphorus salts. Five of these patients died of respiratory failure; however, their deaths occurred from 5 to 41 years following the initial diagnosis. No follow-up information was obtained in two patients.

CONCLUSIONS

The findings of this study confirm that pulmonary alveolar microlithiasis can be seen in any age group and that the microliths are composed principally of salts of calcium and phosphorus. Additionally, these cases confirm that the disease typically follows a protracted course.

Primary intrapulmonary meningiomas. A clinicopathologic and immunohistochemical study of ten cases

BACKGROUND

Primary intrapulmonary meningiomas are rare, and their occurrence has been reported in the literature only sporadically.

METHODS

The clinical, pathologic, and immunohistochemical features of ten cases of primary intrapulmonary meningioma were reviewed.

RESULTS

The patients were 4 women and 6 men between the ages of 30 and 72 years (mean age: 51 years). In nine patients, the lung tumor was found during a routine chest radiographic study. The only patient with clinical symptomatology was a man who presented with a persistent cough of 45 days' duration. None of the patients had a previous history of central nervous system (CNS) meningioma or other tumor at the time of diagnosis. Macroscopically, the neoplasms were described as soft, white, well circumscribed lesions that ranged in size from 1.5 cm to 4 cm in greatest dimension. No predilection for any particular lobe or segment of lung was observed. Histologically, all the tumors showed the characteristic growth pattern of CNS meningiomas and were classified accordingly. Seven tumors were transitional meningiomas, and three were fibrous meningiomas. Psammoma bodies were observed in 50% of the tumors. Immunohistochemically, six cases showed positive staining for Epithelial Membrane Antigen (EMA) and vimentin, whereas two of these cases also showed focal positive staining for CD34. Clinical follow-up ranging from 1 month to 24 years was obtained for 6 patients. All the patients were alive and well except for 1 female who died 20 years after the initial diagnosis at age 92 of a cerebrovascular accident.

CONCLUSIONS

The clinical follow-up in this study suggests that these tumors are amenable to surgical resection, and when the tumor is resected in its entirety, the patient is cured. In addition, the immunohistochemical results suggest that, as in CNS meningiomas, EMA and vimentin are the most reliable immunologic markers for these tumors.

Truly benign "bronchial adenoma". Report of 10 cases of mucous gland adenoma with immunohistochemical and ultrastructural findings

Mucous gland adenoma of the bronchus (MGAB) is a rare, solitary, benign, well-circumscribed, multicystic, predominately exophytic bronchial tumor. Mucous gland adenoma arises from the submucosal seromucous glands and ducts of proximal airways; since the location, signs and symptoms, and bronchoscopic findings are similar to those of other tumors arising in the bronchus, diagnosis depends on tissue biopsy. We herein report 10 patients with MGAB. Patients ranged in age from 25 to 67 years old (mean, 52). In two thirds of patients, the tumor was located in the middle or lower lobes. Tumors ranged in size from 0.8 to 6.8 cm (mean, 1.8). Cut surface was shiny, mucoid, cystic, and usually firm. Mucous gland adenomas are protean in their histologic patterns. They may appear glandular and tubulocystic or papillocystic, and they often show a mixture of these features. The tumors are rich in mucins and are immunopositive for epithelial markers. Mucous gland adenoma needs to be distinguished from low-grade malignant tumors of the bronchus--most notably, low-grade mucoepidermoid carcinoma. Complete removal of the tumor is curative.

Prognostic factors in pulmonary fibrohistiocytic lesions

BACKGROUND

The spectrum of pulmonary fibrohistiocytic lesions (PFL) ranges from benign fibrohistiocytoma or inflammatory pseudotumor, fibrohistiocytic type (IP), to fibrohistiocytic lesions of borderline malignant appearance (B), to unequivocal malignant fibrous histiocytoma (MFH). The authors reviewed a spectrum of PFL in an attempt to define their natural history and establish independent factors of prognostic significance.

METHODS

Thirty-one fibrohistiocytic lesions were analyzed by multiple clinical, gross, and microscopic factors. Prognostic factors were evaluated by univariate and multivariate Cox proportional hazards models.

RESULTS

After histopathologic review, the cases were classified into IP (15 cases), B (3 cases), and MFH (13 cases). IP tended to occur in younger patients (median age, 30 years; range, 11-64 years) than did MFH (median age, 54 years; range, 12-81 years) (P = 0.03). All 15 patients with IP and 3 patients with B survived. Local recurrence developed in 2 patients with IP and 6 patients with MFH. Distant metastases occurred in 7 patients with MFH. Eight of 13 patients with MFH died of disease, with a median survival time of 16 months (range, 6-36). For all pulmonary fibrohistiocytic lesions, univariate Cox regression analysis disclosed several statistically significant prognostic factors associated with mortality: metastasis (P = 0.0005), significant necrosis (P = 0.0015), local recurrence (P = 0.003), bizarre giant cells (P = 0.0282), mitoses greater than or equal to 3 per 50 high-power fields (P = 0.0286), stage at surgery (P = 0.002), high cellularity (P = 0.0267), and poor circumscription (P = 0.0294). Other parameters (age, sex, symptoms, laterality, location, atypical mitoses, nuclear pleomorphism, degree of fibrosis, and size) were not significant prognostic factors. By multivariate Cox regression analysis, metastasis was the most significant individual parameter (P = 0.002), overriding all other prognostic factors. With metastasis removed from the model, local recurrence (P = 0.0199) and necrosis (P = 0.037) were the other significant independent prognostic factors.

CONCLUSIONS

Certain individual clinical, gross, and microscopic features have prognostic relevance in determining survival time in pulmonary fibrohistiocytic lesions.

Adiaspiromycosis: an unusual fungal infection of the lung. Report of 11 cases

Adiaspiromycosis (ad"i-ah-spi"ro-mi-kósis) is a worldwide, noninfectious, nonarthropod transmitted fungal infection of lower vertebrates, most commonly rodents. Humans become an accidental host by inhaling dust-borne spores (conidia) of the saprophytic soil fungus, Emmonsia crescens (recently renamed Chrysosporium parvum variety crescens). We report 11 cases of this unusual deep mycosis from South America, Europe, and the United States. The severity of the disease depends on the number of spores inhaled. In limited inoculum, the disease remains localized (two cases), whereas in heavy inocula the fungus involves both lungs (nine cases) and presents as a diffuse reticulonodular infiltrate. In this disseminated form, patients usually complain of cough, dyspnea on exertion, and low-grade fever mimicking other systemic fungal infections and tuberculosis. It is difficult to unmask the fungus because it is not easily cultured nor is there a reliable serologic test. Therefore, a biopsy is required and the pathologist must recognize the large (ranging in size from 50 to 500 microns), round, Gomori methenamine-silver nitrate and periodic acid-Schiff reagent-positive spherules with a trilaminar wall. The spherules can be surrounded by either suppuration, epithelioid granulomas with or without necrosis, or concentric, hyalinized fibrosis. In the latter chronic stage, the organism may collapse, forming a variety of sizes and shapes thereby resembling other fungi, helminths, mineral particles, or inhaled pollen grains. Clinically, the infection most commonly regresses spontaneously, but may persist, or rarely progress, requiring surgical intervention with limited resection to attain cure.

Pigmented pulmonary carcinoid tumor. An immunohistochemical and ultrastructural study

We evaluated three cases of pigmented pulmonary carcinoid tumors that were retrieved from the files of the Armed Forces Institute of Pathology, Washington, DC. Clinical follow-up showed no indication of tumor recurrence or metastases, nor was there evidence of malignant melanoma. All three cases exhibited histologic features of typical carcinoid tumor; there were focal oncocytic changes in two cases. Finely dispersed, brown pigment, believed to be melanin, was distributed in two different patterns: in sustentacular cells (case 1) or within the tumor cells (cases 2 and 3). Fontana-Masson stain was positive in areas of this pigment in all cases. The tumor cells showed immunoreactivity for chromogranin, synaptophysin, keratin (AE1/AE3 and CAM-5.2), and S100 protein in all cases. Focal staining for vimentin and corticotropin was seen within neoplastic cells in two cases. The pigmented sustentacular cells in case 1 showed focal immunoreactivity for S100 protein and HMB-45. Ultrastructural studies of paraffin-embedded tissues were performed in two cases. They showed well-developed melanosomes in the pigmented sustentacular cells in case 1. In both cases, cytoplasmic neurosecretory-type granules were identified in neoplastic cells. These findings demonstrate that pigmented pulmonary carcinoid tumor has an immunohistochemical profile similar to that of typical pulmonary carcinoid tumor. In some instances, pigmented pulmonary carcinoid tumors may show ultrastructural evidence of melanocytic and neuroendocrine differentiation. These immunohistologic and ultrastructural findings distinguish pigmented pulmonary carcinoid tumor from malignant melanoma and support the concept of "multidirectional cellular differentiation."

Mucinous (so-called colloid) carcinomas of lung

We present 24 cases of primary mucinous (so-called colloid) carcinomas of the lung. The patients were between 33 and 81 yr old (median: 57 yr), including 15 men and nine women. The lesions were discovered incidentally on chest X-ray, where they presented in diverse forms. No predilection for a particular lobe or pulmonary segment was observed. The tumors varied from 0.5 to 10 cm in greatest diameter. Grossly, the tumors were poorly circumscribed, soft, tan-to-gray mucoid lesions. Microscopically, they showed intra-alveolar pools of mucin containing small clusters of atypical cells floating in the mucin, and foci of neoplastic columnar epithelium lining scattered alveoli. Seven cases showed areas of solid, well-differentiated malignant glands adjacent to pools of mucin. In two cases, lymph node metastases were found at surgery. Eleven (57%) of 19 patients were alive over a follow-up period ranging from 2 to 192 mo; one of them had metastases to bone and another had intrapulmonary recurrence. Eight patients died with/of their tumors, two of them with known metastases to bone and/or brain, and one with recurrence after 2 yr of initial diagnosis. No follow-up was obtained in five patients. Although the extent of clinical evaluation varied, no other primary neoplasms (i.e., breast, gastrointestinal tract, or other organs where primary mucinous carcinomas are known to occur) were observed. These tumors probably represent a variant of bronchioloalveolar carcinoma and share the prognosis of that neoplasm. However, because of their often bland cytologic features and paucity of malignant cells, they may be difficult to diagnose as neoplasms.

Pseudomesotheliomatous adenocarcinoma: a reappraisal

Adenocarcinomas of or in lung that clinically and pathologically mimic diffuse pleural mesotheliomas are rare. We reviewed selected clinical and pathologic features of 15 autopsy/surgical cases previously reported in the medical literature and of 15 additional cases from the files of the Armed Forces Institute of Pathology (AFIP). Ninety percent of the patients were men. The median age was 61 years. Sixty-three percent of the patients smoked, 17% of them had possible or definite occupational exposure to asbestos, and one patient had microscopically proven asbestosis. Most patients had chest pain, shortness of breath, or cough, and had unilateral pleural effusion in the chest x-ray. At thoracotomy or at autopsy, numerous nodules, plaques, or a continuous rind of tumor was present over the pleural surface. Microscopically, the tumors showed simplified glands, nests, cords, papillary, tubulopapillary or biphasic patterns of growth. The neoplasms contained mucin that stained with diastase-predigested periodic acid-Schiff (PAS), mucicarmine, and alcian blue (with or without hyaluronidase predigestion). All patients died with/of tumor, with a mean survival of 4.7 months for those reported in the medical literature and of 7 months for those in the AFIP files. These adenocarcinomas therefore mimic pleural mesothelioma not only in their clinical and gross and microscopic appearance, but also in their prognosis.

An immunohistochemical study of benign clear cell ('sugar') tumor of the lung

Benign clear cell ("sugar") tumor is a rare and most unusual pulmonary neoplasm. Although several reports in the literature have focused on the ultrastructural features of benign clear cell tumor, only a few cases have been formally studied by immunochemistry. Using a broad panel of polyclonal and monoclonal antibodies, five cases were evaluated. In all five cases, there was diffuse immunoreactivity for cathepsin B. Four cases showed immunoreactivity for HMB-45 and for alpha 1-antitrypsin. By two different sources for antivimentin, there was immunoreactivity in four cases (Biogenex, Dublin, Calif) and in two cases (DAKO, Santa Barbara, Calif), respectively. Additional immunoreactivity was present for S100 protein (three cases), HAM-56 (two cases), factor XIIIA (two cases), and neuron-specific enolase (one case). No case expressed immunoreactivity for keratin (AE 1, AE 3, or CAM 5.2), carcinoembryonic antigen, chromogranin, synaptophysin, glial fibrillary acidic protein, or alpha 1-antichymotrypsin. This immunochemical profile suggests that HMB-45, in combination with a variety of immunostains, may serve to distinguish benign clear cell tumor from other clear cell neoplasms.

Pulmonary blastomas

Pulmonary blastoma is a rare lung tumor composed of immature mesenchyme and/or epithelium that morphologically mimics embryonal pulmonary structure. The prognosis of these tumors is poor, and the clinical course is not readily predicted from histologic appearance. In this report, the clinical, gross, microscopic, and immunopathologic features of 52 cases are described, and prognostically important correlates are determined. Twenty-eight patients were women, and 24 were men. There was a unimodal age peak in the fourth decade; only two patients were younger than 10 years old, and both had biphasic blastomas. Forty-one percent of patients were asymptomatic. Chest radiography typically showed a peripheral or midlung mass without predilection for any lobe. Microscopically, tumors could be divided into two classes: those composed solely of malignant glands of embryonal appearance (well-differentiated fetal adenocarcinomas [WDFA], 28 cases) and those with a biphasic appearance (24 cases). The malignant epithelium contained cytokeratin, carcinoembryonic antigen, milk fat globulin, and often chromogranin; vimentin, actin, and less frequently desmin and myoglobin were present in malignant stromal cells. More often WDFA was a smaller tumor (less than 5 cm) than biphasic tumors (P less than or equal to 0.001). It was more likely to be asymptomatic (P less than or equal to 0.001), and it was less likely to show pleural effusion by chest radiography (P less than or equal to 0.01) or giant or bizarre tumor cells (P less than or equal to 0.001) or frequent (greater than or equal to 30 mitoses/10 high-power fields) mitoses in the microscopic sections (P less than or equal to 0.01). Only 14% of patients with WDFA died of their tumor; 52% of patients with biphasic tumors died (mean follow-up, 97 months and 49 months, respectively). For patients with WDFA, the presence of thoracic adenopathy by chest radiography (P less than or equal to 0.001) and metastasis at initial presentation (P less than or equal to 0.001), followed by tumor recurrence (P less than or equal to 0.01), were the factors most highly correlated with poor prognosis. For patients with biphasic tumors, tumor recurrence (P less than or equal to 0.001) was the most significant indicator of poor prognosis, followed by metastasis at initial presentation (P less than or equal to 0.05) and gross size of the tumor (greater than or equal to 5 cm) (P less than or equal to 0.05). These findings support the idea that histologic class and gross and clinical findings can be of prognostic value in pulmonary blastoma.

Pulmonary blastomas

Pulmonary blastoma is a rare lung tumor composed of immature mesenchyme and/or epithelium that morphologically mimics embryonal pulmonary structure. The prognosis of these tumors is poor, and the clinical course is not readily predicted from histologic appearance. In this report, the clinical, gross, microscopic, and immunopathologic features of 52 cases are described, and prognostically important correlates are determined. Twenty-eight patients were women, and 24 were men. There was a unimodal age peak in the fourth decade; only two patients were younger than 10 years old, and both had biphasic blastomas. Forty-one percent of patients were asymptomatic. Chest radiography typically showed a peripheral or midlung mass without predilection for any lobe. Microscopically, tumors could be divided into two classes: those composed solely of malignant glands of embryonal appearance (well-differentiated fetal adenocarcinomas [WDFA], 28 cases) and those with a biphasic appearance (24 cases). The malignant epithelium contained cytokeratin, carcinoembryonic antigen, milk fat globulin, and often chromogranin; vimentin, actin, and less frequently desmin and myoglobin were present in malignant stromal cells. More often WDFA was a smaller tumor (less than 5 cm) than biphasic tumors (P less than or equal to 0.001). It was more likely to be asymptomatic (P less than or equal to 0.001), and it was less likely to show pleural effusion by chest radiography (P less than or equal to 0.01) or giant or bizarre tumor cells (P less than or equal to 0.001) or frequent (greater than or equal to 30 mitoses/10 high-power fields) mitoses in the microscopic sections (P less than or equal to 0.01). Only 14% of patients with WDFA died of their tumor; 52% of patients with biphasic tumors died (mean follow-up, 97 months and 49 months, respectively). For patients with WDFA, the presence of thoracic adenopathy by chest radiography (P less than or equal to 0.001) and metastasis at initial presentation (P less than or equal to 0.001), followed by tumor recurrence (P less than or equal to 0.01), were the factors most highly correlated with poor prognosis. For patients with biphasic tumors, tumor recurrence (P less than or equal to 0.001) was the most significant indicator of poor prognosis, followed by metastasis at initial presentation (P less than or equal to 0.05) and gross size of the tumor (greater than or equal to 5 cm) (P less than or equal to 0.05). These findings support the idea that histologic class and gross and clinical findings can be of prognostic value in pulmonary blastoma.

Localized benign and malignant fibrous tumors of the pleura. A clinicopathologic review of 223 cases

We reviewed 223 localized fibrous tumors of the pleura and divided them histologically into 141 benign and 82 malignant neoplasms. The criteria used for a judgement of malignancy were high cellularity and mitotic activity (more than four mitotic figures per 10 high-power fields), pleomorphism, hemorrhage, and necrosis. The tumors occurred equally in both sexes, most commonly in the sixth to seventh decades of life. Presenting symptoms included chest pain, dyspnea, and cough; they were observed in three-fourths of patients with a malignant tumor. One in every four of these patients had hypoglycemia, clubbed digits, or pleural effusion. Two-thirds of the tumors were attached to visceral pleura, often by a pedicle. The rest arose from the parietal pleura of the chest wall, diaphragm, or mediastinum. Neoplasms in these atypical sites, together with fissural lesions and tumors "inverted" into peripheral lung, were more often malignant. Most neoplasms measured 5-10 cm and weighed 100-400 g. Microscopically, the "patternless pattern," or hemangiopericytic type, was seen in the majority of cases, and mixed patterns were seen in nearly 40% of tumors. Of the 169 tumors where follow-up was available, all of the benign and 45% of the malignant tumors were cured by simple excision. Patients surgically cured of a malignant neoplasm had pedunculated or well-circumscribed lesions. However, 55% of patients with malignant tumors succumbed to their disease secondary to invasion, recurrence, or metastasis. Resectability is the single most important indicator of clinical outcome. No tumor expressed epithelial differentiation, either immunohistochemically or ultrastructurally; therefore, we favor the term "localized fibrous tumor" of pleura instead of "localized mesothelioma."

Malignant fibrous histiocytoma of the lung

Twenty-two cases of primary malignant fibrous histiocytoma (MFH) of the lung are described, and a review of the literature is presented. As in the soft tissue, this sarcoma is found primarily in older individuals, usually as a solitary peripheral mass. Chest wall invasion at diagnosis was seen in four cases. The most common histologic subtype was the storiform-pleomorphic type of MFH. Vascular invasion was seen in 50% of cases. Histologic features did not correlate with prognosis, and subsequent aggressive behavior was related primarily to symptomatic presentation, advanced stage at diagnosis, incomplete excision, invasion of the chest wall or mediastinum, and subsequent recurrence or metastasis. Primary MFH of the lung should be distinguished from spindle cell carcinoma and inflammatory pseudotumors, and this histologic differential diagnosis is discussed.

Mucoepidermoid tumors of the lung

Mucoepidermoid tumors of lung (MET) are rare tumors derived from the minor salivary gland tissue of the proximal tracheobronchial tree. The authors studied 58 cases of MET confined to the lung and used criteria derived from similar tumors of the salivary glands to separate them into low-grade and high-grade variants. The overwhelming majority of low-grade tumors behaved in a benign fashion, whereas 23% of high-grade tumors resulted in patient death. Prognostic factors which appeared to predict future aggressive behavior included high-grade classification, advanced stage at presentation, and perhaps lymph node metastases.

Mediastinal hemangiomas

Hemangiomas of the mediastinum are rare tumors. Fewer than 100 have been reported. This study reviews the cases of 15 patients with mediastinal hemangiomas confirmed pathologically. We analyzed and evaluated the presentation, evaluation, and treatment. Follow-up is available for 14 of the 15 patients and ranges from 15 months to 15 years. Eight of the 15 patients were seen with signs and symptoms related to the tumor. This presentation correlated with invasion of contiguous mediastinal structures by the tumor. Six patients underwent total excision and 6, subtotal excision. During follow-up, residual tumor did not spread, become symptomatic, or show evidence of malignant degeneration. Based on this analysis, we believe that in patients in whom total excision of this tumor can be accomplished only by hazardous resection, a subtotal resection should be performed.

Unusual thoracic manifestations of epithelioid hemangioendothelioma

Intravascular bronchioloalveolar tumors are now recognized as the pulmonary analogue of epithelioid hemangioendotheliomas of the somatic soft tissues. These low-grade endothelial sarcomas have a typical histologic appearance and usually present as bilateral pulmonary nodules in young women. The present report describes four unusual clinical manifestations of the epithelioid hemangioendothelioma: as an anterior mediastinal mass, as diffuse pleural thickening resembling malignant mesothelioma, as a metastatic carcinoma with cancerization of the lymphatics (lymphagitic carcinoma), and as a solitary peripheral calcified nodule. These anomalous clinical presentations correspond to unusual histologic appearances of the tumor at open-lung biopsy, and need to be recognized by both the clinician and the pathologist.

Lymphoid interstitial pneumonia: clinicopathological and immunopathological findings in 18 cases

Eighteen patients with lymphoid interstitial pneumonia (LIP) were studied. The diagnosis was established by the microscopic finding of interstitial infiltrates of lymphocytes and plasma cells. Forty-seven% of patients also had germinal centres, while 72% showed interstitial giant cells. Cases studied by the immunoperoxidase technique showed the interstitial plasma cells to be polytypic. The median age of patients was 56 years; most had cough, dyspnea, or chest pain. Chest X-rays showed either patchy interstitial infiltrates (usually bilateral) or poorly defined nodules. Ten patients had hypergammaglobulinemia; one had hypogammaglobulinemia. Two patients had Sjögren's syndrome, two had biopsy-proven chronic active hepatitis, and two had a clinical diagnosis of primary biliary cirrhosis. Follow-up examination of 14 patients showed clearing of symptoms, X-ray infiltrates or stable infiltrates in 4 cases each. Five patients died (mean survival, 41 months), one of whom succumbed to disseminated lymphoma and a second to respiratory failure. Our results support the hypothesis that LIP is a non-neoplastic cellular proliferation in which lymphoma may supervene. The high incidence (22%) of chronic liver disease has not previously been noted.

Sporothrix infection of the lung without cutaneous disease. Primary pulmonary sporotrichosis

The clinical spectrum of sporotrichosis is expanding and now includes pulmonary infection in absence of skin lesions. Lung involvement, albeit unusual, is a granulomatous pneumonitis which may progress to bilateral, apical, fibrotic, and contracted infiltrates or cavities, thereby mimicking tuberculosis or histoplasmosis. The patients are most often middle-aged men with alcoholism and chronic obstructive pulmonary disease. Our case report is yet another variant of primary pulmonary sporotrichosis that presented as diffuse, bilateral granulomatous pneumonitis without cavitation or predilection for upper lobes.

Primary pulmonary hemangiopericytoma

Eighteen cases of primary pulmonary hemangiopericytoma are reported. These pulmonary sarcomas tend to occur in older individuals, frequently as asymptomatic, non-calcified solitary masses on chest radiographs. Morphologically, they have a histology similar to their soft tissue counterparts. No single clinical or histologic feature allowed prediction of biologic aggressiveness in these rare pulmonary sarcomas and the authors recommend that all hemangiopericytomas of lung be considered as potentially malignant.

Malignant mesotheliomas with osseous and cartilaginous differentiation

This report describes ten examples of diffuse pleural tumors felt to represent malignant mesotheliomas with osseous and cartilaginous differentiation. Typically, the patients involved were elderly whites who presented with chest pain, bloody pleural effusions, and diffuse and nodular pleural disease on chest roentgenograms. An asbestos-exposure history was indicated in six of the ten patients. Seven cases were malignant fibrous mesotheliomas, and three were biphasic mesotheliomas. Results of immunoperoxidase studies for cytoplasmic keratin were positive in three of six cases of malignant fibrous mesothelioma.

Pulmonary hyalinizing granuloma

Pulmonary hyalinizing granulomas are distinct fibrosing lesions of lung, having central whorled deposits of lamellar collagen. Twenty-four cases of this unusual pulmonary lesion are reported herein. Hyalinizing granulomas occur in middle-aged persons and are frequently mistaken for metastatic carcinoma radiographically. More than half of the patients had autoimmune phenomena or previous exposures to mycobacterial or fungal antigens. Four patients had sclerosing mediastinitis develop. A progressive debilitating clinical course was related to increasing dyspnea and bilateral disease on chest radiographs. A discussion of the histogenesis and histologic differential diagnosis is presented.

Alveolar adenoma

This report describes six cases of an unusual pulmonary neoplasm, the alveolar adenoma, that consists of a benign proliferation of alveolar epithelium and septal mesenchyme. The neoplasm presents as a solitary peripheral lesion on chest radiographs, particularly in older patients. It has unique histologic features, which should be distinguished from those of sclerosing hemangioma, lymphangioma, and bronchioloalveolar carcinoma.

Lymphomatoid granulomatosis: a clinicopathologic study of 42 patients

We studied the histological and clinicopathological findings in 42 patients who had lymphomatoid granulomatosis (LYG). In addition to small round lymphocytes, small to intermediate lymphocytes with serpentine nuclei, large immature mononuclear lymphoid cells, abundant histiocytes, and vascular invasion by the cell infiltrate were observed in all cases. Fifty percent of lesions had occasional "atypical" cells with multi-lobed nuclei. Three of four follow-up autopsies showed large cell lymphoma, while one other autopsy and the single repeat biopsy showed increased numbers of large immature mononuclear lymphoid cells. Patients were most frequently men 40-60 yr old who had a history of pulmonary symptoms, such as cough or chest pain, and who showed multiple bilateral lung nodules without hilar adenopathy in the chest x-ray. Thirteen patients (38%) died of disease, 11 of them within 12 mth of initial diagnosis. The presence of neurological signs and symptoms, increased mitoses, or increased numbers of atypical multi-nucleated cells in the initial biopsy were not statistically significant predictors of survival.

Amyloidosis presenting in the lower respiratory tract. Clinicopathologic, radiologic, immunohistochemical, and histochemical studies on 48 cases

We studied 48 cases of amyloidosis localized to the lower respiratory tract. Fourteen cases were classified as tracheobronchial amyloidosis. Twenty-eight cases showed solitary or multiple nodules, and six cases had a diffuse interstitial parenchymal pattern. Almost all patients with tracheobronchial and diffuse interstitial amyloidosis had respiratory symptoms (usually dyspnea), whereas most with nodular amyloidosis were asymptomatic. Nodular parenchymal and, less frequently, tracheobronchial amyloidosis had contiguous cellular infiltrates of plasma cells, lymphocytes, and giant cells. Immunohistochemical staining of specimens from 18 cases showed these plasma cells to be polytypic, except for two tracheobronchial lesions that had a disproportionate number of lambda light chain-bearing plasma cells. Permanganate oxidation of specimens from 19 cases showed patterns in keeping with immunoglobulin-derived amyloid in 12. Local deposits of amyloid in lung may arise from deposition of circulating precursor proteins.

Primary pulmonary sporotrichosis. Report of eight cases with clinicopathologic review

Pulmonary sporotrichosis in the absence of lymphocutaneous disease is unusual; however, its incidence may be greater than previously recognized. This report describes the AFIP experience in eight cases of primary pulmonary sporotrichosis and reviews an additional 23 cases. The disease is often a bilateral, apical, chronic and cavitary, progressive, destructive, and debilitating infection, most often seen in middle-aged men with a history of alcoholism and chronic obstructive pulmonary disease. In this clinical setting, pulmonary sporotrichosis closely mimics tuberculosis or histoplasmosis. However, this clinical charade can be unmasked by serologic tests, cultures, and identification of the causative agent, Sporothrix schenckii, in sections of paraffin-embedded lung containing necrotizing granulomas and stained with periodic acid-Schiff and Gomori methenamine-silver nitrate. Previously not recognized is the presentation of primary pulmonary sporotrichosis as a solitary, peripheral, necrotizing pulmonary nodule, observed in two patients. Chronic cavitary pulmonary sporotrichosis is usually refractory to drug therapy; however, when combined with surgical resection, cure can be attained.

Primary non-Hodgkin's lymphoma and pseudolymphoma of lung: a study of 161 patients

The authors studied 161 cases of primary non-Hodgkin's lymphomas and pseudolymphomas of lung. Small lymphocytic proliferations, which they believe to be lymphomas, constituted 31.6 per cent of cases; plasmacytoid lymphocytic and small cleaved follicular center cell lymphomas (Lukes-Collins system), 22.4 and 11.8 per cent of cases, respectively; and the remaining follicular center cell lymphomas and B-immunoblastic sarcomas, 5.6 per cent of cases. Pseudolymphomas constituted 14 per cent of cases. Most patients were elderly and asymptomatic; in most cases a solitary nodule or infiltrate was observed on a chest radiograph. Radiographic evidence of effusion was found in both lymphomas and pseudolymphomas, but hilar adenopathy was restricted to lymphomas. A few peribronchial reactive germinal centers and intralesional giant cells/granulomas were seen frequently in unequivocal lymphomas, so their presence cannot be used to exclude neoplasia. A generally monomorphic cell population and invasion of bronchial cartilage or visceral pleura are suggestive of malignancy, whereas primitive cytologic appearance and invasion of lymph nodes or parietal pleura are pathognomonic of malignancy. Diffusely admixed mature lymphocytes and plasma cells with numerous reactive follicles suggest pseudolymphomas. Immunologic determination of clonality may be diagnostically definitive. Most localized lesions in lung were treated by surgical resection, whereas in cases of extensive pulmonary disease, biopsies were performed and patients were treated by chemotherapy or irradiation. Both lymphomas and pseudolymphomas recurred, most often within three years. Pseudolymphoma recurred only in lung. When distant spread of lymphoma occurred, it commonly involved extranodal sites. Only 18 of 101 patients with lymphoma died with or of tumor, and no patient with pseudolymphoma died of disease. Neither histologic subtype among the "small cell" lymphoid lymphomas nor the presence of regional node involvement was prognostically significant, but pleural effusion on the initial chest radiograph was a significant predictor of both recurrence and mortality.

Bronchocentric granulomatosis: roentgenographic manifestations

The roentgenographic manifestations of bronchocentric granulomatosis were reviewed in 15 patients. Nine patients had mass lesions. Four had alveolar infiltrates and 2 presented with reticulonodular infiltrates . Correlation of these radiographic patterns with the pathologic findings helps explain the varied morphologic appearance of this disease on the chest radiographs. Upper lobe involvement and unilateral disease were predominant. Seven of 15 patients (47%) presented with solitary mass lesions. Pleural reaction was occasionally noted. Hilar adenopathy and cavitation were infrequent. There was little correlation between radiographic pattern and clinical presentation.

Bronchocentric granulomatosis

The clinical and morphologic features in 15 patients with bronchocentric granulomatosis were reviewed. Patients were divided into two groups on the basis of the morphologic findings. Group I consisted of five patients with necrotizing granulomas containing abundant eosinophils in the areas of necrosis. Three of these patients were asthmatic, two had elevated blood eosinophil counts, and in one there were fungal hyphae within necrotizing granulomas. In another case a sputum culture was positive for Aspergillus. The findings in these cases support the contention that some bronchocentric granulomas associated with tissue eosinophilia may represent a hypersensitivity reaction to inhaled Aspergillus. Group II included 10 patients with bronchocentric granulomas showing many polymorphonuclear cells but few eosinophils. One of these 10 had asthma, and blood eosinophilia was found in only one patient. The etiology and pathogenesis of these bronchocentric granulomas in unclear. The differences in morphology and clinical symptomatology between the two groups suggest that these lesions may arise from more than one etiologic agent and pathogenetic mechanism. Follow-up information was available for 11 individuals. Corticosteroids were given to four patients and lesions were resected from five patients. Neither recurrence of bronchocentric granulomas nor death due to them was reported.

Pulmonary blue bodies

Pulmonary blue bodies are intra-alveolar laminated basophilic concretions of uncertain etiology. Blue bodies were studied in lung biopsy specimens from 10 patients. The patients ranged in age from 47 to 69 years and were predominantly men. Three had a history of overt exposure to environmental dusts such as sawdust and asbestos, and two showed occasional ferruginous bodies in the lung, raising the possibility of pneumoconiosis. In eight cases there was interstitial pneumonitis, which resembled desquamative interstitial pneumonia by light microscopy but which was often seen to be patchy and asymmetrically distributed in the lung by chest x-ray examination. Of two other patients, one had xanthogranulomatous inflammation and the other, necrotizing granulomatous inflammation. Light and electron microscopic, histochemical, microchemical, and x-ray diffraction studies of blue bodies were also performed. Calcium carbonate is a major component of blue bodies and is responsible for their birefringence in unstained sections and ready solubility in acid solutions. Blue bodies also contain a mucopolysaccharide matrix and iron. We offer the hypothesis that blue bodies (calcium carbonate) are a product of histiocytic catabolism.

Ganglioneuroblastoma of the posterior mediastinum: a clinicopathologic review of 80 cases

The pathology and clinical course of 80 cases of ganglioneuroblastoma (GNB) of the posterior mediastinum are presented. Many neoplasms in this series had previously been classified as differentiating neuroblastomas or immature ganglioneuromas. The prognosis for this group is far better than that for either neuroblastomas or intra-abdominal GNBs. Follow-up was obtained for 72 patients, of whom 55 were followed for 2-23 years. The five-year actuarial survival rate was 88%. Prognosis was related to histologic growth pattern, age, and extent of disease at diagnosis. Stage I tumors were curable by simple excision; children with Stage II tumors treated with surgery and radiation responded as favorably as did those who received adjunctive chemotherapy. In contrast to those associated with late recurrences, the only examples of fatal primary tumors, with one exception, were those patients with Stage IV lesions at the time of initial diagnosis. The therapeutic implications and need for uniform terminology in classifying GNBs are discussed.

Allergic granulomatosis (Churg-Strauss syndrome): pulmonary and renal morphologic findings

The pulmonary histopathology of four cases of allergic granulomatosis (Churg-Strauss syndrome) was reviewed. Renal tissue was also studied in one case. The patients were young and most presented with asthmatic symptomatology. They showed marked peripheral blood eosinophilia, and had fluffy nodular pulmonary infiltrates by chest x-ray. Serum IgE was elevated in the one patient in whom it was obtained. The lung tissue in all cases showed necrotizing giant-cell vasculitis, interstitial and perivascular granulomas, and eosinophilic pneumonia-like areas. These microscopic features distinguish allergic granulomatosis from other forms of pulmonary eosinophilia or vasculitis. Renal tissue showed necrotizing granulomatous vasculitis and interstitial eosinophilic nephritis, without evidence of glomerulonephritis. Electron-microscopic study of one lung biopsy and of the renal tissue demonstrated tissue eosinophilia and, in lung, a granuloma. There was no evidence of vascular or glomerular electron-dense deposits. These findings are discussed in the light of possible pathogenetic mechanisms of allergic granulomatosis.