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Biomedical subjects

A S Pieterse

Publications and source records attributed to A S Pieterse.

At least 19 recordsLinked to original sources
PubMed1995

Granulomatous lobular mastitis.

Two cases of benign lobular granulomatous mastitis, both clinically felt to be carcinoma, are reported. One patient was cured by local excision of the mass while the other was cured by oral prednisolone, demonstrating the variable ways to treat this entity. The clinical and histological features were similar to those noted in previous reports. Immunological studies revealed predominantly stromal T lymphocytes and only duct intra-epithelial T lymphocytes.

Administration, Oral↗
PubMed1991

Differing characteristics of human papillomavirus RNA-positive and RNA-negative anal carcinomas.

Anal carcinomas were tested for the presence of human papillomavirus (HPV) RNA transcripts by in situ hybridization using 125I-labeled RNA probes. The HPV transcripts were detected in 73.2% of 41 nonglandular anal carcinomas but in none of six anal or 11 rectal adenocarcinomas. In anal nonglandular carcinomas, no difference in the percentage of tumors that were HPV RNA positive was observed between tumors classed as basaloid carcinomas or squamous cell carcinomas. Patients with HPV RNA-negative tumors were significantly older (9.2 years) than those with HPV RNA-positive tumors. Anal intraepithelial neoplasia Grade 3 in the surrounding epithelium was seen in 14 of 25 assessable HPV RNA-positive tumors and in none of nine assessable HPV RNA-negative tumors. Anal tumors may include two separate clinical and biologic groups distinguished by their dependence, or lack of dependence, on HPV RNA expression for maintenance of the neoplastic state.

Adenocarcinoma↗
PubMed1986

Right-sided diverticular disease of the colon: a morphological analysis of 16 cases.

Right-sided diverticular disease is uncommon and represents a heterogeneous group of cases with varying clinical presentation often confused with other disorders. Based on number, size, distribution and histological appearance of the diverticula, four distinct groups were identified, each with a distinct clinical presentation. Six patients had solitary false diverticula mimicking acute appendicitis and at operation were found to have inflamed caecal masses. Five patients had diverticula formed on the basis of defects in the muscularis propria. The mean age of these patients was 30 years older than the previous group and all of them presented with rectal haemorrhage, often confused with angiodysplasia clinically. At laparotomy the external appearance of the bowel was unremarkable. Three patients had diverticular disease similar to that seen in the left side of colon. Two patients had true congenital caecal diverticula confirming that the minority of caecal diverticula conforms to this group.

Acute Disease↗
PubMed1986

Criteria for the diagnosis of primary endocrine carcinoma of the skin (Merkel cell carcinoma). A histological, immunohistochemical and ultrastructural study of 13 cases.

Thirteen cases of primary endocrine carcinoma of the skin (Merkel cell carcinoma) were reviewed with the aim of defining the morphological, immunohistochemical and ultrastructural criteria for diagnosis. The tumour cells were characterized by their scanty cytoplasm, generally small uniform nuclei with finely dispersed chromatin and multiple small nucleoli. Nuclear shapes varied from round to spindle, with larger and pleomorphic forms predominating in 2 tumours. A striking feature seen in 12 tumours was the occurrence of a "ball-in-mitt" pattern represented by 1 or 2 crescentic tumour cells closely wrapped around an oval cell. Staining for neuron-specific enolase was the most consistent marker of the tumour and the characteristic juxtanuclear globular staining for keratin and cytokeratin and the occasional coexpression of neurofilament set this tumour apart from other cutaneous neoplasms, in particular, metastatic carcinoid tumours and oat cell carcinoma from the lung. The fine structural features of note were striking paranuclear or juxtanuclear whorls of intermediate filaments, seen in 7 cases, the presence of variable numbers of membrane-bound dense core granules of 80-150 nm diameter in all cases and cytoplasmic spinous or microvillous projections containing microfilaments in 4 cases. Less consistent characteristics of primary endocrine carcinomas of the skin included cell moulding, argyrophilia and immunohistochemical staining for ACTH, VIP and calcitonin. The high frequency of vessel invasion in this series is in keeping with the high rate of local recurrence, lymph node metastases and visceral dissemination reported. The distinction from other similar appearing tumours in the skin is discussed.

Adult↗
PubMed1985

The mucosal changes and pathogenesis of pneumatosis cystoides intestinalis.

The clinical and pathologic findings in 11 patients with pneumatosis cystoides intestinalis (PCI) are described. Symptoms were variable but localized to the gastrointestinal tract. Only one patient had obstructive airway disease. Although gas cysts of varying sizes were present in the colonic wall in all cases, distinctive changes were also observed in the mucosa. Architectural disturbances were seen in 11 of 13 specimens, and changes mimicking those of inflammatory bowel disease, including cryptitis, crypt abscesses, chronic inflammation, and granulomas, were present. In addition, crypt dilation and partial crypt rupture, with formation of intramucosal cysts, were seen in association with clusters of small gas cysts in the lamina propria. The transgression of gas cysts through the muscularis mucosae and the presence of larger giant cell-lined cysts in the submucosa suggested entry of gas generated in the colonic lumen or within inflamed crypts from the mucosal aspect. Other postulated pathogeneses of PCI are discussed.

Aged↗
PubMed1985

Gastric xanthomas.

Gastric xanthomas (GX) are uncommon intramucosal lesions which can be misinterpreted as early or signet ring adenocarcinoma. The histological features of eight gastric xanthomas are described. Mucin and Masson trichrome strains were valuable in distinguishing GX from adenocarcinoma.

Aged↗
PubMed1984

Clostridium difficile colitis.

We reviewed all rectal biopsies performed on patients with proven C. difficile infection between 1977 and 1982 (36 patients). All patients were symptomatic and all had received antibiotic treatment recently, the commonest antibiotic treatment being ampicillin or amoxycillin. There was poor correlation between the histological appearances and the severity of symptoms. A range of histological appearances was observed: normal (8%), congestion and edema (8%), nonspecific colitis (3%), infective colitis (28%) and pseudomembranous colitis (53%) (PMC). Most cases of PMC showed 'early' features, involving predominantly the surface epithelium, where attenuation and inflammation, intraepithelial microabscesses, and small eruptive lesions were seen. Recognition of these features, in the context of an acute infective-type colitis, may lead to early diagnosis of C. difficile colitis.

Adult↗
PubMed1984

Focal prostatic granulomas rheumatoid like--probably iatrogenic in origin.

Small focal rheumatoid nodule-like granulomas have been noted in the prostatic chips from 11 repeat transurethral resections (TUR) in 10 patients. The lesions are situated in the prostatic stroma and are characterized by a central zone of fibrinoid necrosis, a peripheral palisade of fibroblasts and histiocytes and variable numbers of lymphocytes and giant cells. These granulomas are only noted in prostatic tissue from repeat TURs, are not evident in the original TUR tissue and probably have an iatrogenic basis. As yet, they appear to be of no clinical significance, but the entity is not well recognized, and the surgical pathologist should guard against over-interpretation of the lesions.

Aged↗
PubMed1983

Perhexiline maleate induced cirrhosis.

Perhexiline maleate is a potent anti-anginal drug which may cause alcoholic-type hepatitis and cirrhosis. We report a case of a patient who developed cirrhosis on a relatively low dose within 16 mth.

Aged↗
PubMed1982

Tracheopathia osteoplastica: a study of the minimal lesion.

We describe the pathological findings in a case of tracheopathia osteoplastica (TPO) of minimal extent. Although described clinically such minimal lesions have not been previously studied pathologically. Our observations lend strong support to the view-point that the nodules of TPO develop as ecchondroses of the tracheal cartilage rings. It is anticipated that TPO of minimal extent will be increasingly identified clinically and diagnosed on biopsy specimens.

Humans↗
PubMed1982

Chronic radiation injury to the intestine: a clinico-pathological study.

This paper draws attention to the continuing problem of chronic radiation injury to bowel. Fifty-seven symptomatic patients with this disorder were studied, 31 with predominantly small bowel injury and 26 with colonic disease. The mean latent interval following irradiation was 4.7 years. Small bowel disease presented initially as intestinal obstruction (19 cases) or malabsorption (11 cases) and the radiation related mortality in small bowel disease was 32%, while that for colonic disease was 4%. There was a high incidence of prior pelvic surgery and of adjunctive chemotherapy in patients developing small bowel disease. Analysis of the radiotherapy techniques used highlighted that an unsatisfactory distribution of radiation dosage occurred when parallel opposed fields were used particularly where one field only was treated daily. Difficulty in matching external beams with intracavity sources may also have contributed to radiation injury.

Female↗
PubMed1982

Collagenous colitis: a distinctive and potentially reversible disorder.

A case of collagenous colitis is reported. The patient's symptoms cleared up after a course of mepacrine hydrochloride. Biopsies taken after clinical recovery still showed some increase in the number of reticulin fibres present in the upper layers of the lamina propria but the subsequent six years.

Colitis↗
PubMed1982

Adamantinoma of long bones: clinical, pathological and ultrastructural features.

The clinical, pathological and ultrastructural features of two cases of tibial adamantinoma are described. Both lesions showed identical features with a mixed histological picture exhibiting baseloid, tubular and squamous differentiation and a prominent stromal (mesenchymal) component. By light microscopy there appeared to be an intimate relation between the epithelial and mesenchymal components. By electromicroscopy the cellular constituents of these components could be readily distinguished. In the former the cells contained tonofilaments and desmosomes which were associated with basement membrane material. In the latter (mesenchymal component) none of these features was notes, instead the cells appeared similar to fibroblasts and occasional myofibroblasts.

Adult↗
PubMed1982

Angiodysplasias of the colon.

We studied 14 large bowel resections from patients with a provisional clinical diagnosis of a bleeding vascular lesion of the colon. For the purpose of this study we developed a barium-gelatine vascular injection technique. Six of the 14 cases were proven to be angiodysplasias with an identifiable mucosal vascular ectasia. The pathological findings in these six cases are described. We conclude that angiodysplasia represent a significant cause of lower gastrointestinal haemorrhage in the elderly. It is our opinion that only the mucosa vascular ectasia seen in these cases is histologically diagnostic and that sub-mucosal venous ectasia, while characteristic of angiodysplasia, is non-specific. the differential diagnostic features which will allow the histological distinction of angiodysplasia from other vascular lesions of the colon are discussed.

Aged↗
PubMed1982

Fibroma of tendon sheath.

A series of nine cases of fibroma of tendon sheath is described including details of the ultrastructural features of two cases. The series was composed of lesions from six males and three females with a mean age of 38 yr. The most common site of involvement was the hand (including fingers) and the mean greater diameter was 19 mm. Typically the tumours were lobulated and microscopically there was a collagenous stroma with spindle and stellate cells in a moderate degree of cellularity. One recurrence was noted in the series. The lesion was distinguished from circumscribed fibromatosis, nodular fasciitis, neurofibroma, leiomyoma, scar tissue, giant cell tumour of tendon sheath (localised nodular tenosynovitis) and fibrous histiocytoma. Ultrastructural studies revealed that the large majority of cells present in the two cases studied were myofibroblasts and fibroma of tendon sheath is therefore the third instance of a benign tumour containing these cells (the other two being dermatofibroma and giant cell fibroma of the oral mucosa).

Adolescent↗