A.J. Howat

Cavitation of mesenteric lymph nodes: a rare complication of coeliac disease, associated with a poor outcome

Five cases are presented, all of which showed peculiar cavitation of mesenteric lymph nodes. Clinically, three presented with abdominal symptoms, a mass or obstruction, warranting laparotomy. Two patients showed cavitating mesenteric lymph nodes at autopsy. Lymph nodes were enlarged with central, partly cystic degeneration; milky fluid exuded from the cut surface. In each case, investigation showed intestinal villous atrophy and splenic atrophy; coeliac disease was confirmed by response to gluten withdrawal. Three patients died, two from cachexia and the other from pneumonia; the other two are alive and well one year and six years after presentation. Review of the literature shows 12 previously reported cases, with a mortality of about 50%. The diagnosis is made by the histopathologist, alerting appropriate treatment. The pathogenesis is unknown.

Angiotropic lymphoma with endocrine involvement.

Aims: Two cases of angiotropic high‐grade B‐cell lymphoma are described in which involvement of endocrine glands was a prominent feature. Methods and results: One patient had marked unilateral adrenomegaly due to lymphoma within adrenal blood vessels. He is alive 5 years after presentation following combination chemotherapy. The diagnosis was made at autopsy in the second patient who presented with pyrexia of unknown origin and had hypothyroidism and a thyroid nodule. The thyroid gland and pituitary showed striking involvement by angiotropic lymphoma and the thyroid nodule was a cavernous haemangioma heavily colonized by lymphoma cells. Conclusions: Our cases illustrate endocrine organ manifestations of this rare disease. The condition may respond to combination chemotherapy.

Myofibroblastoma of breast: evidence favoring smooth-muscle rather than myofibroblastic differentiation.

A histopathological study of two cases of the tumor known in the literature as myofibroblastoma of the breast is presented. The tumors occurred in Caucasian males aged 57 and 62 years. Histologically, these were moderately cellular, lobulated spindle-cell lesions, each with a reasonably well-delineated edge with surrounding fatty connective tissue. No breast ducts or lobules were present. Tumor cell nuclei were bland, with small nucleoli and some nuclear grooving. Nuclear atypia and mitoses were absent. Immunostaining revealed positivity for a-smooth-muscle actin, desmin, and CD34. Tumor cells contained rough endoplasmic reticulum, bundles of myofilaments with focal densities, intermediate filaments, attachment plaques alternating with plasmalemmal caveolae, and focal lamina. Ultrastructural findings pointed to true smooth-muscle differentiation, and the cell-surface in particular lacked surface features of myofibroblasts (fibronectin fibrils [microtendons] and fibronexus junctions). These and published data suggest that at least some of the lesions referred to in the literature as myofibroblastoma may not be myofibroblastic and may be better designated as myogenic stromal tumors or as variants of leiomyoma.

An EMA negative, desmin positive malignant mesothelioma: limitations of immunohistochemistry?

Histopathologists in the current environment of medical negligence and litigation are more likely to use immunohistochemical investigations in their day-to-day practice to support their diagnosis and avoid future litigation. The caveat is that relying on immunohistochemistry is a double-edged sword and pathologists should be familiar with its limitations. We present a case of primary malignant peritoneal mesothelioma with an unusual immunohistochemical profile—desmin positive, EMA negative—and wish to highlight the importance of cautiously interpreting immunohistochemistry profiles when they do not fit the clinical history and histological appearance.

Dissecting aneurysm of the pulmonary artery associated with a large facial cavernous haemangioma

Less than 40 cases of dissecting aneurysm of the pulmonary artery have been described, almost all single case reports. Diagnosis was made in life in only three instances, two by Doppler echocardiogram and one by magnetic resonance scanning. Approximately 80% of affected patients have had pulmonary arterial hypertension, usually caused by a congenital cardiac anomaly, and most have also had atherosclerosis or cystic medial necrosis affecting the pulmonary arterial tree. Rare causes include endocarditis, amyloidosis and bronchial carcinoma. We describe a case of pulmonary artery dissection in a patient with a large cutaneous haemangioma of the face. There was evidence of cystic medial necrosis of the main pulmonary arteries but no evidence of congenital heart disease, pulmonary hypertension or pulmonary artery atheroma.

Lymph nodes in Henoch‐Schönlein purpura

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