An Autopsy Case of Pulmonary Capillary Hemangiomatosis with an Electron Microscopy Study.

BACKGROUND Pulmonary capillary hemangiomatosis (PCH) and pulmonary veno-occlusive disease (PVOD) are rare diseases that share clinical, X-ray, and histological features. Most patients have poor prognosis due to severe respiratory impairment. Recently, EIF2AK4 mutations were found in some patients with PCH and PVOD, but the role of this mutation is still unknown. We report an autopsy case of PCH and discuss a mechanism of respiratory dysfunction based on an electron microscopy study. CASE REPORT The patient was a Japanese man in his sixties. He suffered from acute exacerbation of dyspnea during treatment of COPD. Respiratory function testing revealed DLCO' 32.1% and DLCO'/VA 23.6%. Echocardiography demonstrated findings consistent with pulmonary hypertension. A CT scan showed mild emphysema and small ground-glass opacity in the lungs. However, we could not find the exact cause of his respiratory failure and he died 28 days after admission. At autopsy, the histology showed multilayering capillary proliferation within the alveolar walls. Electron microscopy examination revealed prominent widening of the air-blood barrier, scarce fusion of the epithelial and capillary basement membranes, and frequent narrowing of the capillary lumen. CONCLUSIONS We reported an autopsy case with PCH with no histological findings of PVOD. Whether PCH and PVOD are 2 different histological patterns of the same disease remains to be verified. The changes in the air-blood barrier detected by electron microscopy may explain the respiratory impairment and pulmonary arterial hypertension.

High frequency of apoptosis in infantile capillary haemangioma.

Infantile capillary haemangioma (ICH) is a well-established clinicopathological entity which often regresses spontaneously. To elucidate the cause of spontaneous involution of ICH, the apoptotic and proliferative activities in seven cases of ICH were compared with those in five cases of lobular capillary haemangioma (LCH), using formalin-fixed paraffin-embedded tissue sections. The number of apoptotic cells detected by the modified in situ end-labelling method was significantly higher in ICH than in LCH, while the proliferative activities evaluated with mitosis and Ki-67 antigen expression did not differ significantly. Lewisy (Ley) antigen, an apoptosis-associated marker, was expressed in all cases of ICH but in none of LCH, while labelling for p53 protein and bcl-2 protein was almost completely negative in both tumours. These findings clearly demonstrate a much higher apoptotic activity in ICH than in LCH and suggest that apoptosis might be a cause of the spontaneous involution of ICH.

Ultrastructural study of hemangiomas in children.

An electron microscopic study was carried out of different kinds of hemangiomas (capillary, cavernous and combined) in 18 children at the age of two months up to one year. Centers of differently expressed proliferation both of the endothelial cells and pericytes were found. The proliferation was most distinctly expressed in the capillary and cavernous hemangiomas. At the later stages, regressive and involutive changes, presented better in the capillary hemangiomas, were observed. The authors consider that hemangiomas, irrespective of their active cell growth, are tumours with a good prognosis.

[Capillary testicular hemangioma: a case report]. / Hemangioma capilar testicular. A propósito de un caso.

Testicular tumors in infants are rare and most of them are malignant. Hemangioma of the testis is an extremely rare tumor in infants. We report on an intratesticular capillary hemangioma that appeared in a 10 month-old child subsequently undergoing orchidectomy and on the patient's evolution at 4 years. The histological characteristics showed proliferation of small blood vessels, lined with endothelial cells. Mitoses and atypias were not found. Permitting differential diagnosis with other vascular tumors: Masson's vegetant intravascular hemangio-endothelioma and angiosarcoma.

Histogenesis of hemangiomas--an ultrastructural study on capillary and cavernous hemangiomas of the skin.

13 capillary hemangiomas of the skin were examined by electron microscopy in order to elucidate their histogenesis. The findings show that the histogenetic development of hemangiomas is similar to that of embryonal and fetal capillaries. Initially the undifferentiated angioblastic anlage gives rise to solid buds, which subsequently receive a lumen, thus turning into primitive capillaries. This developmental stage corresponds to early embryonic vasculogenesis. The growth of angiomas is mainly due to sprouting, which as in fetal and postnatal vasculogenesis takes place from both primitive and mature capillaries. These findings support the classical theories on the histogenesis of angiomas (angioblastic and sprouting theories). The question whether in all cases hemangiomas have to pass through all developmental stages or whether it is possible that part of them develops directly from the normal capillary network of the skin by a process of sprouting remains open to discussion. Finally the findings in one cavernous hemangioma and two tele-angiectasias were compared and discussed.