Single institution followed by national implementation of systematic surgical quality control and feedback for radical prostatectomy: a 20-year journey

Purpose

The demand for objective and outcome-based facts about surgical results after radical prostatectomy (RP) is increasing. Systematic feedback is also essential for each surgeon to improve his/her performance.

Methods

RP outcome data (e.g., pT-stage and margin status) have been registered at Sahlgrenska University Hospital (SUH) since 1988 and patient-related outcome measures (PROM) have been registered since 2001. The National Prostate Cancer Registry (NPCR) has covered all Regions in Sweden since 1998 and includes PROM-data from 2008. Initially PROM was on-paper questionnaires but due since 2018 all PROMs are collected electronically. In 2014 an on-line “dashboard” panel was introduced, showing the results for ten quality-control variables in real-time. Since 2017 all RP data on hospital, regional, and national levels are publicly accessible on-line on “www.npcr.se/RATTEN”.

Results

The early PROM-data from SUH have been used for internal quality control. As national clinical and PROM-data from the NPCR have been made accessible on-line and in real-time we have incorporated this into our pre-existing protocol. Our data are now internally available as real-time NPCR reports on the individual surgeons’ results, as well as ePROM data. We can compare the results of each surgeon internally and to other departments’ aggregated data. The public can access data and compare hospital level data on “RATTEN”.

Conclusions

The process of quality control of RP locally at SUH, and nationally through the NPCR, has been long but fruitful. The online design, with direct real-time feedback to the institutions that report the data, is essential.

Inguinal hernia is a common complication in lower midline incision surgery

Inguinal hernia is a known complication after radical retropubic prostatectomy (RRP). We have investigated whether other types of lower midline incision surgery in males increase the risk of inguinal hernia. Male patients operated with open prostatectomy for benign prostate hyperplasia (n = 95), pelvic lymph node dissection for staging of prostate cancer (n = 88), or cystectomy for bladder cancer (n = 76) were identified and were sent questionnaires in which they were asked about postoperative inguinal hernia morbidity. Two-hundred and seventy-one men operated with RRP had previously received a similar questionnaire. The answers were compared with those from a control group of 953 men who had not undergone surgery. Annual attributional hernia morbidity and Kaplan-Meier hernia-free survival were calculated. The cumulative incidence of post-operative inguinal hernia and annual attributional hernia morbidity after the respective surgical procedures were clearly higher during the early years post-operation than for nonoperated patients. Inguinal hernia is a common postoperative complication in males after all the lower midline incision surgery investigated.

Population-based screening for prostate cancer by measuring free and total serum prostate-specific antigen in Sweden

OBJECTIVE

To report the initial results from Sweden of a large population-based randomized study of screening using prostate-specific antigen (PSA) to detect prostate cancer, as the efficacy of such screening to decrease prostate cancer mortality has not yet been proven.

METHODS

From the population registry men aged 50-66 years were randomized to screening (9973) and to future controls (9973). Men randomized to screening were invited to have their serum measured for free PSA (fPSA) and total PSA (tPSA) in serum using the Prostatus f/tPSA assay (Perkin-Elmer, Turku, Finland). Men with a tPSA of < 3.0 ng/mL were not further investigated, while those with a tPSA of > or = 3.0 ng/mL were investigated with a digital rectal examination (DRE), transrectal ultrasonography (TRUS) and sextant biopsies.

RESULTS

Of those invited, 60% accepted PSA testing and 11.3% had a tPSA of > or = 3.0 ng/mL. Altogether 145 cancers were detected (positive predictive value, PPV, 24%); none were stage M1, two were stage N+ and 10 stage T3-4. Most (59%) cancers were impalpable and 39% were both impalpable and invisible on TRUS. At biopsy, 7% were Gleason score 2-4, 71% 5-6, 19% 7 and 2% Gleason score 8-10. A threshold tPSA of > or = 4.0 ng/mL would have detected 109 cancers in 366 biopsied men (PPV 30%) while cancer detection would have been 14% higher with a PPV of 36% using a threshold tPSA of > or = 3.0 ng/mL combined with a f/tPSA threshold of < or = 18%.

CONCLUSIONS

PSA screening detects early-stage low-grade prostate cancer. Both the sensitivity and specificity can be increased by incorporating f/tPSA with a tPSA threshold of < 4 ng/mL.

A randomised comparison of bicalutamide ('Casodex') 150 mg versus placebo as immediate therapy either alone or as adjuvant to standard care for early non-metastatic prostate cancer. First report from the Scandinavian Prostatic Cancer Group Study No. 6

OBJECTIVES

To assess the efficacy and tolerability of bicalutamide 150 mg ('Casodex'(1)) as immediate therapy, either alone or as adjuvant to treatment of curative intent, in patients with early (T1b-T4, any N, M0) prostate cancer.

METHODS

This randomised, double-blind study was conducted in the Nordic countries as part of the 'Casodex' Early Prostate Cancer programme. Patients received bicalutamide 150 mg (n=607) or placebo (n=611) in addition to standard care.

RESULTS

More than 80% of patients had not received therapy of primary curative intent. Median follow-up in both groups was 3 years. Median exposure to study treatment in the bicalutamide and standard care alone groups was 2.5 and 2.3 years, respectively. Bicalutamide reduced the risk of objective disease progression by 57% compared with standard care alone (HR 0.43; 95% CI 0.34, 0.55; p<<0.0001). Survival data were immature (11.4% deaths) with no difference between the two treatment groups.

CONCLUSIONS

Bicalutamide 150 mg as immediate therapy, either alone or as adjuvant to treatment of curative intent, significantly reduces the risk of disease progression in patients with early prostate cancer. The trial is ongoing to assess whether the reduction in risk of objective progression translates into an overall survival benefit.

Inguinal hernia after radical retropubic prostatectomy for prostate cancer: a study of incidence and risk factors in comparison to no operation and lymphadenectomy

PURPOSE

The incidence, mechanisms and risk factors of inguinal hernia after radical retropubic prostatectomy are sparsely elucidated in the literature. We determined the rate of inguinal hernia after radical retropubic prostatectomy and compared it to the incidence in patients with prostate cancer who did not undergo operation or underwent only pelvic lymph node dissection.

MATERIALS AND METHODS

We followed 375, 184 and 65 men who underwent radical retropubic prostatectomy plus pelvic lymph node dissection, pelvic lymph node dissection only and no surgery with respect to inguinal hernia for a mean of 39, 47 and 45 months, respectively. The prostatectomy group was also evaluated in regard to the potential risk factors of previous hernia surgery and post-prostatectomy anastomotic stricture.

RESULTS

The incidence of hernia was 13.6%, 7.6% and 3.1% in the prostatectomy, lymph node dissection and unoperated group, respectively. The difference was statistically significant in the prostatectomy and unoperated groups according to the Mantel-Cox log rank test and Cox proportional hazards rate. Previous hernial surgery and post-prostatectomy anastomotic stricture were more common in patients with an inguinal hernia after prostatectomy.

CONCLUSIONS

The incidence of inguinal hernia is clearly increased in men who have undergone radical retropubic prostatectomy plus pelvic lymph node dissection compared with those who undergo no surgery for prostate cancer. Inguinal hernia appears to develop more often in men with prostate cancer who undergo radical retropubic prostatectomy and pelvic lymph node dissection than in those who undergo pelvic lymph node dissection only. While surgical factors trigger hernial development, previous hernial surgery and post-prostatectomy anastomotic stricture may be important risk factors. In fact, the latter may largely explain the difference in the incidence of inguinal hernia in our lymph node dissection and prostatectomy groups. Prophylactic surgical procedures must be evaluated to address this problem.

Outcome of laterally directed sextant biopsies of the prostate in screened males aged 50--66 years. Implications for sampling order

OBJECTIVE

Prostate cancer has its most frequent location in the posterior-lateral part of the gland. The aim of this study was to evaluate the cancer detection rate of six systemic prostate biopsies with mid lobar biopsies taken far laterally in the prostate.

PATIENTS AND METHODS

A total of 692 patients (aged 50--66 years) enrolled in a screening study underwent prostate biopsies because of an elevated serum prostate-specific antigen (PSA; > or =3 ng/ml) level. The outcome of the biopsies was related to findings at digital rectal examination (DRE) and transrectal ultrasound (TRUS) and to the location within the prostate.

RESULTS

Prostate cancer was detected in 164 patients. DRE and TRUS were suspicious of malignancy in 66 cases (40%) and 84 cases (51%), respectively. The two biopsies taken far laterally midlobar in the prostate detected as many as 83% of the cancers and when combined with two apical biopsies, 96% of all cancers were detected.

CONCLUSION

At PSA screening in this age-group, only 57% of the prostate cancers detectable by sextant biopsies were palpable or visible at TRUS. Most of the cancers (96%) were detectable by only four systematic, carefully directed biopsies. In men with normal DRE, the two lateral midlobar biopsies should be taken first during the biopsy procedure.

Would prostate cancer detected by screening with prostate-specific antigen develop into clinical cancer if left undiagnosed? A comparison of two population-based studies in Sweden

OBJECTIVE

To assess the risk of over-diagnosing and over-treating prostate cancer if population-based screening with serum prostate-specific antigen (PSA) is instituted.

PATIENTS AND METHODS

From a serum bank stored in 1980, PSA was analysed in 658 men with no previously known prostate cancer from a well-defined cohort from Göteborg, Sweden (men born in 1913); the incidence of clinical prostate cancer was registered until 1995. From the same area, and with the same selection criteria, another cohort of 710 men born in 1930-31, who in 1995 accepted an invitation for PSA screening, was also analysed.

RESULTS

Of men born in 1913, 18 (2.7%) had died from prostate cancer and the cumulative probability of being diagnosed with clinical prostate cancer was 11.1% (5.0% in those with a PSA level of < 3 ng/mL vs 32.9% in those with a PSA level of > 3 ng/mL, P < 0.01). The mean lead-time from increased PSA (> 3 ng/mL) to clinical diagnosis was 7 years. The prostate cancer detection rate in men born in 1930-31 was 4.4% (22% among those with increased PSA levels) and 30 of 31 detected cancers were clinically localized.

CONCLUSIONS

Screening and sextant biopsies resulted in a lower detection rate (22%) than the cumulative risk of having clinical prostate cancer (33%) in men with increased PSA levels, indicating that under-diagnosis rather than over-diagnosis is the case at least with 'one-time' screening. Even if the stage distribution in screening-detected cancers seems promising (and thus may result in reduced mortality) it is notable that screening 67-year-old men will result in treatment a mean of 7 years before clinical symptoms occur and only one in four men anticipated to develop prostate cancer will die from the disease within 15 years. Large randomized screening trials seem mandatory to further explore the benefits and hazards of PSA screening.

Bladder rupture due to accidental oxygen insufflation via an indwelling urethral catheter--a report of two cases

Two cases of bladder rupture caused by accidental insufflation of oxygen through an indwelling urethral catheter are described. Both patients were ill with multiple diseases. Conservative treatment, including an open indwelling urethral catheter, and surveillance of abdominal status seem appropriate when managing this complication.

Transrectal ultrasound with separate measurement of the transition zone volume predicts the short-term outcome after transurethral resection of the prostate

OBJECTIVES

To determine whether the volume of prostatic adenomas as assessed by transrectal ultrasound (TRUS) influenced the outcome after transurethral resection of the prostate (TURP).

METHODS

TRUS with total prostate and transition zone (TZ) volume determinations was performed preoperatively in 298 consecutive patients undergoing TURP for benign prostatic hyperplasia without prior urodynamic evaluation. Postoperatively, the outcome of surgery was stated as excellent (no or minor remaining symptoms), improved (but with some remaining symptoms), or failure (the same or aggravated symptoms) according to a patient-administered questionnaire. Six possible risk factors were evaluated: TZ volume 20 cc or less, neurologic disorders, previous TURP/transurethral incision of the prostate (TUIP), diabetes, indwelling catheter, and age older than 80 years.

RESULTS

Thirty patients (10.1%) had treatment failure, 45 (15.1%) improvement, and 223 (74.8%) had excellent outcome. After subdivision into preoperative TZ volume of 20 cc or less and greater than 20 cc, it was found that the outcomes of 20.9% (n = 19) were failures if the TZ volume was 20 cc or less but only 5.3% (n = 11) if the TZ volume was greater than 20 cc. Additional independent risk factors for failure were neurologic disorders and previous TURP/TUIP. When all patients with risk factors were excluded (TZ volume 20 cc or less, neurologic disorders, previous transurethral surgery, and diabetes), the risk of failure was 3.3%.

CONCLUSIONS

Patients with a preoperative TZ volume greater than 20 cc and no history of neurologic disorders, previous TURP/TUIP, or diabetes had a very high chance of favorable outcome after TURP, even though no pressure/flow evaluation had been performed preoperatively.

Characteristics of screening detected prostate cancer in men 50 to 66 years old with 3 to 4 ng./ml. Prostate specific antigen

PURPOSE

We defined the yield and nature of prostate cancer in the setting of population based, randomized prostate specific antigen (PSA) guided screening in men with PSA levels between 3 and 4 ng./ml. who were 50 to 65 years old at the time of randomization.

MATERIALS AND METHODS

Sextant biopsies were performed in 243 men with PSA of 3 to 4 ng./ml. Therapy decisions were based on core cancer length, histological grade and life expectancy.

RESULTS

Of the men 32 (13.2%) had prostate cancer constituting 23% of all of the 137 prostate cancers to data detected in the first round of our screening study. Age and PSA were similar in men with and without prostate cancer. Men with prostate cancer had significantly lower free PSA and free-to-total PSA ratio, and higher PSA density. Cancer was clinical stage T1c in 27 cases and stage T2 in 5. Hypoechoic areas were noted at transrectal ultrasound in 10 cases. Digital rectal examination and transrectal ultrasound were normal in 21 cases (66%). To date 14 patients have undergone prostatectomy. Surgical specimens showed a mean tumor volume of 1.8 cc (range 0.6 to 4.4) and significant amounts of high grade tumor were present in only 3 cases. Margins were positive in 5 cases, and pathological stage was pT2 in 8 cases and pT3 in 6.

CONCLUSIONS

By lowering the PSA cutoff from 4 to 3 ng./ml. an increase in cancer detection by 30% was achieved. While the addition of free-to-total ratio and PSA density may reduce the number of biopsies by about 15% with sensitivity maintained at 90%, systematic sextant biopsies were necessary in most of these mean as 66% of the tumors were negative on transrectal ultrasound and digital rectal examination. The majority of these cancers were clinically significant and suitable for curative treatment. If therapy decisions are based on the pathological findings of the biopsies, the risk of treating insignificant cancers seems low.

Lower urinary tract symptoms. A comparison of micturition symptoms in patients scheduled for transurethral prostatic resection and outpatients of both sexes referred for non-urological complaints

The presence of ten different micturition symptoms was investigated by means of a patient-administered questionnaire in 355 males and females over 50 years of age referred for non-urological complaints, and compared to those of 131 patients selected for transurethral prostatic resection (TURP) due to symptomatic benign prostatic hypertrophy. Each symptom was evaluated further by a subsequent "bother" question and the questionnaire also contained a global "bother" question. Each of the symptoms was significantly more frequent and pronounced in the TURP group than in the control group. Moderate or severe symptoms were found in 25% of males and 18% of females in the control group as compared to 92% in the TURP group. In the control group most symptoms increased with age regardless of sex, and this was most pronounced for weak stream and hesitancy. Males in the control group had a significantly higher total symptom score than females (5.3 vs 4.3; p < 0.05). This difference was, however, mainly due to higher scores in weak stream, hesitancy and post-micturition dribbling in males. Females tended to have more urgency. The symptom scores and the associated "bother" scores were highly correlated, indicating that each symptom carried the same potential to bother the patient. The single global "bother" question gave an adequate reflection of the combined "bother" scores, and seems sufficient in the evaluation of the individual patient's concern.

Primary carcinoid tumour with ossification masquerading as calyx stone in a horseshoe kidney

A case of renal carcinoid tumour arising within a teratoma in a horseshoe kidney in a 23-year-old male is reported. The presenting symptom was abdominal pain, and bone tissue within the tumour was initially misinterpreted as a calyx stone, leading to unsuccessful attempts at extracorporeal shock-wave lithotripsia and percutaneous lithotripsia. This unusual tumour is over-represented in patients with horseshoe kidney and other congenital developmental renal defects.

Reference range of prostate-specific antigen after transurethral resection of the prostate

OBJECTIVES

The aim of the present study was to investigate how transurethral resection of the prostate (TURP) affected the serum levels of prostate-specific antigen (PSA) and to establish reference ranges of PSA in patients who have undergone TURP.

METHODS

PSA was determined preoperatively and 3 months postoperatively in 190 patients who underwent TURP because of benign prostatic hyperplasia (BPH).

RESULTS

Mean PSA levels were reduced by 70%, from 6.0 to 1.9 ng/mL. Prostate volume was reduced by 58% from 63.3 to 26.5 cc, which is close to the reported normal volume in men without BPH. Ninety percent of the patients had a postoperative PSA value of less than 4 ng/mL and 98% less than 10 ng/mL.

CONCLUSIONS

After a complete TURP with a benign histopathologic specimen, PSA should be expected to be within the normal reference range, that is, less than 4 ng/mL.

Influence of benign prostatic hyperplasia, testosterone and age on serum levels of prostate specific antigen

Prostate specific antigen (PSA) and PSA-density (PSAd) were studied in 120 symptomatic patients with benign prostatic hyperplasia at digital rectal examination. PSA and PSAd were measured before and 3 months after transurethral resection. Comparisons were made between patients in whom histologic examination showed benign hyperplasia and those with histologically demonstrated prostatic cancer. The influence of age and of serum testosterone on PSA and PSAd was determined. PSAd in benign prostatic hyperplasia was the same in the transition zone (the adenomas) and the peripheral zone (mean 0.065), indicating no increased synthesis or leakage of PSA. PSAd with cut-off value 0.10 ng x ml-1 x cc-1 showed higher sensitivity and positive predictive value (75% vs 50% and 0.33 vs 0.15, respectively) in nonpalpable prostatic cancer than did PSA with cut-off at 4 ng x ml-1. No statistically significant influence of testosterone and/or age on serum-PSA or PSAd was found.

Metastases of malignant melanoma simulating soft tissue sarcoma. A clinico-pathological, light- and electron microscopic and immunohistochemical study of 21 cases

Metastases of cutaneous malignant melanoma (MM) of ordinary type can resemble various types of soft tissue sarcoma light microscopically to a degree which has not been previously recognized. Twenty-one cases are described, in which the tumours were originally diagnosed as a soft tissue sarcoma. Seven tumours were predominantly of blue and spindle-cell, fascicular type, resembling malignant peripheral nerve sheath tumour and at times monophasic synovial sarcoma. Ten tumours which were of fascicular and predominantly storiform type, and included uni- and multi-nuleated pleomorphic cells resembled malignant fibrous histiocytoma. Due to the presence of multivacuolated lipoblast-like tumour cells, 2 of these 10 tumours resembled pleomorphic liposarcoma. One had a predominantly myxoid and hypocellular appearance and 5 additional tumours included such areas. The diagnoses were revised after ultrastructural examination with the demonstration of melanosomes in 13 of 16 studied cases and the immunohistochemical demonstration of positivity using anti-S-100 protein antibodies and the anti-melanoma antibody NKI/C3 in all cases. The anti-melanoma antibody HMB 45 gave a positivity in 9 of 21 cases. Light microscopically, sparse amounts of melanin were noted in 7 tumours using the Whartin-Starry technique. Eleven tumours occurred at sites close to major lymph node groups and in 9 of these cases, lymphoid tissue was associated with the tumours, suggesting that they represented lymph node metastases. Following a review of the patients' clinical histories and renewed clinical examination, primary cutaneous MM was demonstrated in 10 of 21 patients and in 1 case an MM in regression was detected. The origin of the 10 tumours without a detected primary is discussed, including the possibility of an overlooked primary, spontaneous regression of a primary and a de novo origin from lymph nodes and soft tissues.

Cellular schwannoma. A clinicopathologic study of 29 cases

A series of 29 cellular schwannomas is described in terms of their clinical presentation and course, light and electron-microscopic appearance, immunohistochemical properties and cytogenetics. The study indicates that cellular schwannoma can be defined as a subtype of classical schwannoma, characterized by spindle cells forming a compact fascicular, sometimes fibrosarcoma-like growth pattern, a low mitotic activity, a generally moderate nuclear and cellular polymorphism and a high degree of Schwann cell differentiation as seen by electron microscopy and immunohistochemistry. The tumour is characteristically located close to the vertebral column, in the mediastinum or retroperitoneum and has a benign course. Occasionally bone destruction and neurological symptoms develop. The clinical appearance together with the high cellularity, fascicular pattern and mitotic activity had led to the erroneous diagnosis of a soft tissue sarcoma in a few cases, and cellular schwannoma may thus be considered to be a pseudosarcoma. Immunohistochemically, cellular schwannomas appear to deviate from classical schwannomas and malignant peripheral nerve sheath tumours by their expression of glial fibrillary acidic protein. The chromosome analysis revealed a normal diploid stemline karyotype, with a variety of abnormal clones, including one with monosomy 22.

Epithelioid malignant schwannoma. A study of 14 cases

We report a light and electron microscopic, immunohistochemical, clinical and prognostic study of 14 patients with epithelioid malignant schwannoma. In 8 patients the tumour involved a major nerve. The tumours were rather small in most instances, the largest diameter being less than 5 cm in 7 cases. Light microscopically, they showed highly cellular areas of epithelioid, polygonal or rounded cells characteristically forming cords and rows and arranged in nodules of varying size. Spindle cell sarcoma areas as in classical malignant schwannoma were seen in 9 cases, and neurofibromatous areas in one case. Four cases were entirely epithelioid in appearance. Electron microscopically the epithelioid tumour cells showed nuclei with mostly even contours containing one or two trabecular or reticular nucleoli, cytoplasmic projections, intra-cytoplasmic myelin-like figures, intercellular junctions and discontinuous, sometimes multilayered external lamina material. The ultrastructural findings indicate that epithelioid malignant schwannoma is a tumour of neural crest derivation having features of Schwann cell differentiation. Immunohistochemically, S-100 protein was demonstrated in 7 tumours and neuron specific enolase in 3. There was a female predominance, 9/14, and a median age of 38.5 years (range 17-74). The extremities, including the hip and shoulder regions, were the most common sites, 12/14. The tumour proved highly malignant; 9 of 14 patients were dead at the time of follow-up and a high incidence of metastasis (7 of 14) was observed.

Vascularization of peripheral neurilemomas: angiographic, computed tomographic, and histologic studies

The vascularization of peripheral neurilemoma was studied in 17 patients, in eight by angiography and in 16 by computed tomography (CT) using contrast enhancement. Angiographically the degree of vascularity varied from scarcity to abundance of vessels. In two patients, arteries connected to the proximal and distal poles of the tumor could be identified as nutrient arteries of the affected nerve, and in three patients some of the veins draining the tumor followed the course of the nerve. All 16 tumors examined by CT showed lower density than skeletal muscle. They were well delineated and at least partially surrounded by adipose tissue. With contrast enhancement the density increased focally, reflecting the distribution of vessels in the tumors. Histologic examination showed that Antoni-A tissue was rich in small (below 15 micron) and medium-sized vessels, whereas large vessels (above 100 micron) were more frequently seen in Antoni-B tissue. Medium-sized and large vessels often tended to be arranged along the border between Antoni-A and Antoni-B tissues.

Metastasizing myxopapillary ependymoma of the sacrococcygeal region. A clinico-pathologic, light- and electronmicroscopic, immunohistochemical, tissue culture, and cytogenetic analysis of a case

A case of recurrent and metastasizing subcutaneous myxopapillary ependymoma of the sacrococcygeal region in a 44-year-old man is reported. The tumor was characterized light microscopically by numerous papillary projections, lined by epithelium-like cells, with a variable degree of polymorphism. Histochemical analysis relating to glucosaminoglycans indicated the presence of hyaluronic acid and chondroitin-4- and/or 6-sulfate. Using immunoperoxidase techniques, glial fibrillary acidic protein (GFAP) and S-100 protein were demonstrated within the tumor cells. Ultrastructurally, the tumor cells were characterized by an abundance of intermediate cytoplasmic filaments, prominent interdigitating cytoplasmic projections, the formation of desmosomes and external lamina-like material. The growth pattern in the tissue culture of this tumor is described, and the ultrastructural appearance of the cultured cells revealed features similar to the primary and recurrent tumor. Chromosome analyses by the G-banding technique of early generations of cultured tumor cells revealed a normal diploid stemline without gross chromosomal deviations. Among the different variant cells and clones recorded, those with X chromosome deviations were of special interest since gonosomal deviations have previously been observed in other types of glioma. The differential diagnosis against adenopapillary carcinoma, chordoma and malignant teratoma is briefly discussed.

S-100 protein in melanocytic tumors. An immunohistochemical investigation of benign and malignant melanocytic tumors and metastases of malignant melanoma and a characterization of the antigen in comparison to human brain

An immunohistochemical investigation regarding the presence of S-100 protein in benign and malignant, primary and metastatic melanocytic tumors is reported. The studied series consisted of 15 benign nevi, 3 blue nevi, 4 juvenile melanomas, 1 balloon cell nevus, 30 primary malignant melanomas of skin, mucous membranes and conjunctiva and 30 metastatic malignant melanomas. The immunohistochemical analysis showed positive staining for S-100 protein within the majority of the tumor cells in all benign tumors examined, except the balloon cell nevus, as well as in all the primary and metastatic malignant melanomas, including low-differentiated epitheloid or spindle-cell types without demonstrable melanin pigment. The results indicate that S-100 protein is a valuable marker for melanocytic tumors, especially in the fairly frequent dilemma of malignant melanoma presenting as a solitary non-pigmented metastasis of uncharacteristic light-microscopic appearance, and without known primary tumor. A characterization and quantification of the S-100 protein immunoreactivity in 5 metastatic malignant melanomas is presented. Using immuno-electrophoresis, the presence of 3 antigenic S-100 determinants was demonstrated within homogenates from the malignant melanomas, including the previously characterized S-100 A (alpha/beta) and S-100 B (beta/beta), and suggesting the presence of a hitherto undescribed variant of S-100 protein, possibly consisting of 2 alpha-subunits. Using rocket immuno-electrophoresis, the amount of S-100 protein was estimated.

Clear-cell sarcoma of tendons and aponeuroses. An immunohistochemical and electron microscopic analysis indicating neural crest origin

A clinico-pathological, light microscopic and immunohistochemical study of 15 clear-cell sarcomas, with an ultrastructural analysis of 6 of the tumors, is presented. The tumors showed a strong predilection for tendons and aponeuroses of the extremities in predominantly young and middle-aged people. The clinical setting, course and light microscopic appearance agree well with the original description by Enzinger (1965). Nine of the 15 patients developed metastases, most of them including lymph nodes, and 8 of the patients had died at the time of follow-up (median follow-up time 4.8 years). Reducing pigment was demonstrated within the cells of 2 tumors. Ultrastructurally the 6 tumors studied had a uniform appearance with characteristically rounded or oval tumor cells with a single nucleus containing one or two very prominent nucleoli, a light-staining cytoplasm with a moderate amount of organelles and a variable content of glycogen. Polymorphic melanosomes were seen in the cells of one of the tumors. External laminas enclosed groups of tumor cells and invested parts of individual tumor cells. With immunoperoxidase analysis for S-100 protein positive staining was observed in the vast majority of the tumor cells of all 15 clear-cell sarcomas. Metastases appearing in 9 of the 15 cases showed positive staining for S-100 protein. There was a strong staining of the cytoplasm and generally a weak and varying staining of nuclei. The immunohistochemical and electron microscopic findings indicate that clear-cell sarcoma is a homogenous entity among soft tissue sarcomas, of probable neural crest derivation.