Biomedical subjects

P W Lam

Publications and source records attributed to P W Lam.

9 recordsLinked to original sources

PubMed1997

Nasal pleomorphic adenoma with skeletal muscle differentiation: potential misdiagnosis as rhabdomyosarcoma.

Pleomorphic adenoma can show diverse lines of differentiation in the epithelial and myoepithelial elements, such as cartilage, bone, and fat. Myoid differentiation, however, has not been documented. We report an unusual case of nasal pleomorphic adenoma which shows focal skeletal muscle differentiation. The tumor was discovered only after successful radiation therapy for an undifferentiated carcinoma of the nasopharynx. Apart from being of morphological interest, the presence of cells with skeletal muscle differentiation also raises the practical issue of possible confusion with rhabdomyosarcoma in a biopsy. The distinguishing features are lack of cytological atypia and presence of a neoplastic glandular element.

Adenoma, Pleomorphic↗

PubMed1996

Fibrosing cholestatic hepatitis in renal transplant recipients.

Fibrosing cholestatic hepatitis in a specific histologic manifestation of hepatitis B virus infection consisting of periportal fibrosis, hepatocyte ballooning, cholestasis, a relatively scant inflammatory infiltrate, and marked overexpression of hepatitis B viral antigens in hepatocytes. Until recently, fibrosing cholestatic hepatitis had been reported only in recipients of liver allografts. In this report, we present two patient in whom this lesion developed following renal transplantation. Both patients had previous liver biopsies showing relatively mild histologic changes. In one patient, the lesion developed early after retransplantation, during the period of maximal immunosuppression. However, in the second patient this lesion developed after withdrawal of immunosuppression. In both cases, death occurred within a few months because of progressive liver disease. Since this lesion can develop in "relatively healthy" hepatitis B carriers following transplantation of organs other than liver, these patients should have careful monitoring of their liver disease. Moreover, since the disease may progress despite withdrawal of immunosuppression, these patients would clearly benefit from the development of more effective therapies for posttransplant hepatitis B.

Adult↗

PubMed1996

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Aged↗

PubMed1996

Clinics in diagnostic imaging (15). Carotid body tumour.

A 30-year-old Chinese woman presented with an enlarging pulsatile swelling in the left neck. A similar right neck mass was excised 2 years previously. Digital subtraction angiography showed a well-defined, hypervascular tumour situated at the left common carotid arterial bifurcation, typical of a carotid body tumour. Complete resection of the second carotid body tumour was achieved. The clinical and imaging features of this tumour are described.

Adult↗

PubMed1995

Clinics in diagnostic imaging (2). Juvenile gouty arthropathy with associated nephropathy.

A 36-year-old Chinese man presented with clinical and biochemical features of renal failure. He has had recurrent attacks of acute gouty arthritis since the age of 15 years. Present radiographic features of extensive chronic tophaceous gout included soft tissue masses, calcification, and typical erosions in the hand and feet. The condition of familial juvenile gouty nephropathy is discussed. Awareness of juvenile-onset gouty arthropathy should lead to early investigation, diagnosis and appropriate management. The complication of associated nephropathy may potentially be prevented.

Adult↗

PubMed1993

Localized polyarteritis nodosa of breast--report of two cases and a review of the literature.

Two patients with localized polyarteritis nodosa involving the breast are reported. They presented with tender breast masses which were excised because of suspicion of carcinoma. The pathological features were similar with vasculitis of medium-sized and small arteries. The medium-sized arteries showed intimal fibroplasia, fragmentation of internal elastic lamina and inflammatory cellular infiltration. Fibrinoid vasculitis involving small arteries indicated a diagnosis of polyarteritis nodosa rather than giant cell arteritis. Both patients remain well. The differential diagnosis of these two arteritides and of Wegener's granulomatosis involving the breast is reviewed.

Aged↗

PubMed1992

Multiclefted nuclei. A helpful feature for identification of intermediate trophoblastic cells in uterine curetting specimens.

Intermediate trophoblast is a distinct form of trophoblast, the presence of which in uterine curettings is considered a reliable indicator of intrauterine pregnancy even in the absence of chorionic villi. However, the appearance of intermediate trophoblastic cells have not been described in sufficiently specific terms to permit their reliable identification, and distinction from decidual cells can be difficult. We have noticed for some time that the intermediate trophoblastic cells often show multiple deep clefts in the nuclei, and the present study was performed to address the issue of whether this nuclear feature is reliable for their identification. We reviewed 242 uterine curettings of intrauterine pregnancy, documented by the presence of chorionic villi, and were able to find a distinct population of cells with large, hyperchromatic, multiclefted nuclei scattered in the decidua in 88% of the cases. In most instances, these cells produced a characteristic variegated pattern that was readily recognizable at low magnification. Positive immunostaining for cytokeratin (CAM 5.2) in these isolated cells within the decidua confirmed their trophoblastic nature. In contrast, multiclefted nuclei were absent in the 51 negative control cases, which included decidualized endocervical polyps (40 cases), uterine curettings from patients with tubal pregnancy (10 cases), and endometriosis with decidual change (one case). We conclude that intermediate trophoblastic cells can usually be reliably identified in curettings of intrauterine pregnancy by their characteristic nuclear multiclefting.

Cell Nucleus↗

PubMed1991

Anaplastic large cell Ki-1 lymphoma involving bone marrow: marrow findings and association with reactive hemophagocytosis.

This report describes the bone marrow findings in four patients whose marrow was involved by anaplastic large-cell Ki-1 lymphoma, an uncommon event in this type of lymphoma. In the marrow aspirate smears, the involvement was subtle, and was in the form of isolated large cells with irregular nuclear configuration, coarse chromatin, prominent nucleoli, and basophilic cytoplasm which might be vacuolated. One case showed paradoxically massive involvement in the trephine biopsy taken from the same site as the marrow aspirate. Reactive histiocytic proliferation with hemophagocytosis was also present. Since marrow aspirate or biopsy may be the first pathologic specimen examined in patients having anaplastic large-cell Ki-1 lymphoma, it is important to be able to recognize the small population of neoplastic cells, which should lead to prompt treatment or further investigations as deemed necessary.

Adolescent↗

PubMed1990

The role of transcutaneous electrical nerve stimulation in management of labour in obstetric patients.

The study evaluated the effect of transcutaneous electrical nerve stimulation (TENS) in the management of labour. It comprised of 125 subjects with 93 primiparae and 32 multiparae. They were divided into 3 groups. The first group received electrical stimulation from the TENS unit (TENS); the second group (placebo group) had the TENS machine connected but with no current from the TENS unit (TPL); whereas the third group had no machine application (control group). Analgesic requirements, pain assessment, labour duration, Obstetric outcome, and the comments from mother and midwife were analysed. No negative effects on the mothers and babies were reported. Neither was there any objective clinical significant differences demonstrated among the 3 groups.

Adolescent↗