Neonatal sunburn and melanoma in mice.

Retrospective epidemiological data have indicated that cutaneous malignant melanoma may arise as a consequence of intense, intermittent exposure of the skin to ultraviolet radiation, particularly in children, rather than from the cumulative lifetime exposure that is associated with other forms of skin cancer. Here we use a genetically engineered mouse model to show that a single dose of burning ultraviolet radiation to neonates, but not adults, is necessary and sufficient to induce tumours with high penetrance which are reminiscent of human melanoma. Our results provide experimental support for epidemiological evidence that childhood sunburn poses a significant risk of developing this potentially fatal disease.

Pulmonary pathology of Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare non-Langerhans' cell histiocytosis that may present with pulmonary symptoms. The condition seems to be nonfamilial and typically affects middle-aged adults. Radiographic and pathologic changes in the long bones are diagnostic, but patients often present with extraskeletal manifestations. Advanced pulmonary lesions are associated with extensive fibrosis that may lead to cardiorespiratory failure. The clinical, radiologic, and pathologic features of six patients with ECD with lung involvement are presented. The patients were three men and three women (mean age, 57). Five presented with progressive dyspnea, and one presented with diabetes insipidus. Open-lung biopsies showed histiocytic infiltrates in a lymphangitic pattern with associated fibrosis and lymphoplasmacytic inflammatory infiltrates. The histiocytes did not stain with periodic acid-Schiff. Immunoperoxidase studies performed on specimens from five of six patients showed that the histiocytes were positive for CD68 and Factor XIIIa and negative for CD1a. Specimens from two patients exhibited immunoreactivity for S-100 protein. Electron microscopy studies performed on specimens from two patients showed phagocytic lysosomes but no Birbeck granules. Clinical follow-up of up to 16 years was available. At the end of that time, five patients were dead of complications related to their disease; one patient remains alive 4 years after diagnosis but with severe respiratory compromise. ECD is a rare non-Langerhans' cell histiocytosis that may present as interstitial lung disease and resemble other pulmonary conditions, particularly usual interstitial pneumonitis and pulmonary Langerhans' cell histiocytosis. Recognition of this entity will allow better assessment of its true incidence, therapeutic options, and prognosis.

Primary anaplastic large cell lymphoma of the lung: a clinicopathologic study of five patients.

Primary anaplastic large-cell lymphoma is a rare malignancy in the lung. Anaplastic large-cell lymphoma characteristically involves the lymph nodes or skin, with few reports from other sites. We studied the clinical and pathologic features of five cases of anaplastic large-cell lymphoma limited to the lungs. The patients were three women and two men aged 27 to 66 years (mean, 44.6 y) The tumors ranged in size from 1.1 to 5 cm. All patients were CD 30 (Ki-1) positive and CD 15 (LeuM-1) negative. Epithelial membrane antigen immunoreactivity was seen in two patients. Epstein-Barr virus was not detected by immunohistochemistry (four patients tested) or by polymerase chain reaction studies (three patients tested). The immunophenotypes were T cell (n = 3) and null (n = 2). Gene rearrangement studies supported the immunophenotypic findings. One patient who had underlying HIV infection died of infectious complications. One patient died at 6 months. Two patients developed recurrent disease and are alive after 42 and 51 months of follow-up. The remaining patient is alive at 8 years of follow-up without evidence of disease. ALCL can mimic metastatic or primary carcinoma and should be considered in the differential diagnosis of large cell neoplasms of the lung.

p21waf1/cip1 and transforming growth factor beta 1 protein expression correlate with survival in non-small cell lung cancer.

p21waf1/cip1 encodes a cyclin-dependent kinase inhibitor that is transcriptionally activated by the p53 tumor suppressor gene, transforming growth factor beta 1 (TGF-beta 1), AP2, and other pathways. Because p21waf1/cip1, p53, and TGF-beta 1 all regulate apoptosis and the cell cycle, we tested the hypothesis that their relative protein levels would correlate with biological features including the survival of non-small cell lung cancer (NSCLC) patients. We conducted an immunohistochemical analysis of p21waf1/cip1 and TGF-beta 1 and identified four patient groups with distinct survival outcomes. Concordant p21waf1/cip1 and TGF-beta 1 expression (i.e., either high p21waf1/cip1 and high TGF-beta 1 expression or low p21waf1/cip1 and low TGF-beta 1 expression) predicted 70% disease-free survival at 2000 days of follow-up. Discordant p21waf1/cip1 and TGF-beta 1 expression (i.e., either high p21waf1/cip1 and low TGF-beta 1 expression or low p21waf1/cip1 and high TGF-beta 1 expression) predicted 35% disease-free survival (P = 0.0003; log-rank test). These survival relationships were not attributable to differences in grade, stage, or p53 status. Although current models do not fully explain these complex interactions, most of these data fit a paradigm whereby TGF-beta 1 regulation determines NSCLC survival. In addition to the survival correlation, we found that high p21waf1/cip1 protein expression correlated with high tumor grade (P = 0.014). There is little evidence that p21waf1/cip1 protein levels accurately predict p53 mutation status in NSCLC; specifically, 20 of 48 (42%) tumors with p53 mutations contained high levels of p21waf1/cip1 protein. These findings indicate that p21waf1/cip1 immunohistochemical analysis may provide useful information concerning the biological properties of NSCLC.

Diffuse panbronchiolitis: histologic diagnosis in unsuspected cases involving North American residents of Asian descent.

OBJECTIVE: To study and report two cases of diffuse panbronchiolitis in patients of Asian ancestry residing in the United States and to review the literature pertaining to this disease. DESIGN: Diffuse panbronchiolitis is a progressive interstitial pneumonitis occurring primarily in Japan. Rare cases are now being identified in Europe and North America. Patients often have a history of sinusitis, present with dyspnea on exertion, and show a restrictive pattern on pulmonary function tests. The clinical, radiologic, and pathologic features of two cases of the disease received for consultation at the Armed Forces Institute of Pathology, Washington, DC, are reported with a review of the literature. RESULTS: Chest radiographs revealed bilateral small nodular opacities with ill-defined borders. High-resolution computed tomography demonstrated the abnormalities to have a centrilobular distribution. Histologically, there was transmural chronic inflammation centered on the terminal bronchioles and an interstitial infiltrate of foamy macrophages. CONCLUSION: Diffuse panbronchiolitis may be mistaken for other more common small airway diseases and may be underrecognized in Western nations. The immigration of Asians and sporadic case reports involving non-Asians make recognition of this disease entity important, as the implications for therapy are different than that of other small airway diseases.

Immunohistochemical study of matrix metalloproteinases and their tissue inhibitors in pulmonary Langerhans' cell granulomatosis.

OBJECTIVE: To evaluate the role of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in the pathogenesis of the lesions of pulmonary Langerhans' cell granulomatosis. DESIGN: Immunohistochemical and confocal microscopic studies were made of lung biopsy specimens from five patients with pulmonary Langerhans' cell granulomatosis. RESULTS: The reactivity of Langerhans' cells was moderate to intense for MMP-2, weaker for MMP-9, and faint for TIMP-1 and TIMP-2. Type IV collagen colocalized with MMP-2 in areas of damage to epithelial basement membranes, a finding that emphasizes the potential importance of this enzyme in the pathogenesis of the destructive lesions of pulmonary Langerhans' cell granulomatosis. In the more advanced fibrotic lesions, TIMP-2 colocalized with basement membranes and with fibrillar collagen, suggesting that it contributes to the permanence of the fibrosis. CONCLUSION: These results indicate an important role for MMPs and TIMPs in pulmonary Langerhans' cell granulomatosis.

Coccidioidomycosis: a persistent threat to deployed populations.

The world-wide deployability of aircrew members exposes them to a peculiar array of medical problems. Non-immune populations, upon deployment to endemic areas, may present to the deployed flight surgeon with acute, poorly recognizable syndromes, such as acute coccidioidomycosis. Alternatively, the acquisition of the chronic progressive form of coccidioidomycosis in endemic areas may be a problem for the flight surgeon, who may be faced with a poorly recognizable syndrome which first manifests itself weeks to months after the crewmember's return from deployment. We describe three cases of coccidioidomycosis in service members that highlight the difficulty in the diagnosis of this disease. These cases prompted an epidemiologic survey of recent cases of coccidioidomycosis among Air Force beneficiaries, presented here, to better define the impact of this disease on personnel assigned to endemic areas. A brief discussion of the epidemiologic and clinical features of the disease and of the aeromedical disposition of the aviator is presented.

Decompression sickness: risk factors and the monoplace chamber--a case report.

Discussions regarding the use of monoplace chambers for the treatment of decompression sickness (DCS) have continued for some time. Recently the role of these chambers has been reviewed by Kindwall (12) and critiqued by Moon (13). Various principles and concerns presented in their articles are illustrated by this case presentation of type II (serious) DCS with pulmonary and neurologic manifestations. Closely timed recurrent altitude exposure is discussed as a risk factor for DCS. Also, a newly defined risk factor (menstrual phase) is considered relevant to this case. Finally, we recommend that arrangements be made early in the management of DCS cases for transfer to a chamber which can provide definitive therapy.

The risk of developing decompression sickness during air travel following altitude chamber flight.

Approximately 35,000 students are trained annually in United States Air Force (USAF) altitude chambers. Students who depart the training site via aircraft on the same day as their altitude chamber exposure may place themselves at increased risk for decompression sickness (DCS). Air travel as a passenger in the immediate post-chamber flight period is unrestricted by current USAF regulations. A retrospective study was conducted to assess the potential risk involved in such post-chamber flight travel. During the years 1982-87, there were 292 cases of DCS involving altitude chamber students which were subsequently treated with hyperbaric oxygen therapy. Only seven cases were found wherein the student was asymptomatic prior to air travel and subsequently developed DCS. Because the percentage of students who postpone travel is unknown, a precise relative risk could not be determined. Although the number of cases where sequential chamber and aircraft hypobaric exposures has initiated DCS is small, the potential for such occurrences remains a health concern.