Charles G. Watson

Concise parathyroidectomy: The impact of preoperative SPECT 99mTc sestamibi scanning and intraoperative quick parathormone assay

BACKGROUND Results of initial operation for sporadic primary hyperparathyroidism are generally excellent, yet today there is pressure to improve outcome and resource utilization. METHODS We designed a prospective longitudinal cohort study comparing two approaches to concise parathyroidectomy. Strategy A was defined as the palpation method for selective unilateral exploration. Strategy B was defined as the routine use of both preoperative 99mTc sestamibi single photon emission computed tomography (SPECT) imaging and intraoperative quick parathormone assay. With either strategy the study period was 19 months and patients explored unilaterally were candidates for same-day discharge. We compared surgical outcome for 128 consecutive consenting patients each with 6 months or more of follow-up (mean 12 +/- 7.6 months). RESULTS Demographic, biochemical and pathologic findings did not differ between groups. SPECT imaging precisely localized hyperfunctioning parathyroid tissue. Compared with Strategy A (n = 61), the 67 patients treated by use of Strategy B experienced a higher rate of unilateral exploration (41.0% versus 62.7%, p < 0.00001) and a shorter length of stay (1.07 versus 1.90 days, p < 0.00001) and tended to have shorter operative times, fewer operative failures, and less morbidity. Total perioperative costs did not differ between groups. CONCLUSIONS Routine use of intraoperative quick parathormone measurement and preoperative 99mTc sestamibi SPECT is as safe, effective, and cost-effective as conventional approaches to parathyroidectomy. Use of this strategy is associated with significant reductions in extent of surgery and length of hospital stay.

Prognostic markers in pheochromocytoma

Clinical and histopathological features do not reliably distinguish between benign and malignant pheochromocytomas. Additional markers that might be useful prognostic indicators in the pathological assessment of these tumors are sought. Immunohistochemical expression of MIB-1, Bcl-2, cathepsin B, cathepsin D, basic fibroblast growth factor (bFGF), c-met, and type IV collagenase were studied on formalin-fixed tissue from 33 nonconsecutive cases of pheochromocytoma, selected on the basis of reliable long-term follow-up, to determine associations with malignancy. The study group included 33 patients, 19 men and 14 women, with a mean age of 45 years, including five cases of neurofibromatosis (NF), three familial, and one MEN IIb. Mean follow-up was 63.2 months. Ten patients were determined to have malignant pheochromocytomas by the presence of metastatic disease. Features found to be associated with malignancy included MIB-1 labeling index (5% vs 1%) (P = .0009), male gender (90% vs 43%) (P = .008), extra-adrenal location (40% vs 9%) (P = .03), tumor weight (481 g vs 124 g) (P = .05), and young age (38 years vs 49 years) (P = .05). None of the five cases with NF were malignant (P = .04). S-100 positivity showed a significant (P = .02) but nonlinear association with benign tumors. Absent S-100 correlated with greater tumor weight. Malignancy was not associated with right versus left side or bilaterality, although bilateral tumors were smaller. C-met, bFGF, cathepsin B, cathepsin D, and collagenase were strongly expressed in most tumors and were not predictive of outcome, nor was bcl-2, which was variably expressed. Using multiple logistic regression with malignancy as the dependent variable, MIB-1 continued to show a significant association with malignancy (P = .005) independent of any association with sex, age, or extra-adrenal location. Using a cutoff value of MIB-1 labeling of greater than 3% yielded a specificity of 100% and a sensitivity of 50% in predicting malignancy.

The pathologic assessment of primary hyperparathyroidism and its impact on therapy. A prospective evaluation of 50 cases with oil-red-O stain.

Normal and abnormal parathyroid glands removed surgically from 50 consecutive patients with primary hyperparathyroidism were studied by means of hematoxylin and eosin and oil-red-O stains. This was done to establish the incidence of the different pathological entities in our patient material, and to evaluate the role of the oil-red-O stain in the diagnostic histopathological process. The oil-red-O stain distinctly separates abnormally hyperfunctioning from normal or suppressed parathyroid tissue. Therefore, it is a valuable tool in the pathologic evaluation of patients with hyperparathyroidism. Chief cell adenomas were the most frequent lesions (88%), while diffuse hyperplasia was seen less commonly (10%) and carcinoma infrequently (2%). These findings justify a surgically conservative approach as the most desirable in managing patients with primary hyperparathyroidism.

Evaluation of the Patient with Suspected Extrahepatic Biliary Obstruction

The causes of jaundice are diverse, are often difficult to identify using clinical criteria alone, and usually require specific therapy for resolution. The diagnostic evaluation should be expeditious but not precipitous. The causes may be characterized as hemolytic, hepatocellular, and obstructive (intrahepatic and extrahepatic).

Atypical Fat Staining Patterns in Hyperparathyroidism

Intracytoplasmic lipid content reflects the metabolic state of parathyroid cells, and staining for this is a useful adjunct in the evaluation of parathyroid glands excised in the treatment of hyperparathyroidism. The procedure, however, is not without limitations, as the unexpected presence of lipid in abnormal, hyperfunctioning glands or its absence in normal glands is occasionally encountered. In this study, the authors review the oil red O staining patterns of 524 parathyroidectomy cases to determine the validity of the stain as well as possible clinical and pathologic correlations. Twenty-seven cases (5.2%) were identified with problematic oil red O staining on which adequate clinical follow-up and pathologic material were available for review. Mean follow-up time was 32 months for this subgroup. The most common problem was the presence of lipid within adenomas (19 cases) or hyperplastic glands (6 cases). Markedly decreased or absent lipid in normal, adenoma-associated glands was seen in two cases. The intensity and distribution of lipid staining in hyperfunctioning glands varied. In four cases, 2/19 adenomas and 2/5 hyperplasia, diffuse positivity, similar to normal parathyroid, were observed. If weak or only focally strong staining patterns are considered to be consistent with hyperfunctioning glands, only six cases, two adenomas, two hyperplasias, and two normal glands could not be resolved. Oil red O stain is useful in diagnosing abnormally functioning parathyroid glands, and, if attention is paid to the staining pattern, few atypical patterns are encountered. Int J Surg Pathol 3(3):163-168, 1996