Staining For Keratin Research Articles

Hepatocellular carcinoma with sarcomatous change arising after radiofrequency ablation for well-differentiated hepatocellular carcinoma

We report a case involving well-differentiated hepatocellular carcinoma (HCC) developing to HCC with sarcomatous changes after radiofrequency ablation (RFA). In a cirrhotic patient with both hepatitis B surface antigen and hepatitis C virus RNA, a well-differentiated HCC with a diameter of 2 cm was detected in segment IV of the liver. A combination of transcatheter arterial embolization and percutaneous ethanol injection (PEI) was performed and, after 8 months, PEI was performed for recurrent tumors. Fifteen months after the first treatment, a recurrent tumor measuring 3.5 cm in diameter was detected in segment IV, which was demonstrated as well-differentiated HCC by tumor biopsy, and treated by RFA. Although the treated lesion was reduced to 2.5 cm in diameter 6 months after RFA, the tumor rapidly enlarged to 6 cm in diameter 2 months later and progressed to lymph node metastasis. Aspiration biopsy showed spindle-shaped sarcomatoid cells with positive staining for both vimentin and keratin. The patient died of HCC progression 10 months after RFA. Autopsy findings showed both sarcomatoid cells and trabecular HCC cells. The sarcomatoid cells had metastasized to the lymph nodes and distant organs. This is the first case illustrating a sarcomatous HCC after RFA. Of interest, RFA may be related to the development of sarcomatous HCC.

Evaluation of immunohistochemistry and multiple-level sectioning in sentinel lymph nodes from patients with breast cancer.

Abstract Context.—Previous investigations on sentinel lymph node biopsies have demonstrated their importance in nodal staging of patients with breast cancer. However, sentinel node biopsy in breast cancer is currently a controversial procedure and continues to provoke debate. Objectives.—We designed our study to determine the usefulness of a standard protocol for evaluating sentinel lymph node metastases and to assess the value of sentinel node biopsy as the only procedure in nodal staging in breast cancer patients. Materials and Methods.—A retrospective analysis of 84 breast cancer patients with sentinel node biopsies, who also underwent axillary dissection, was conducted using a standard protocol (3 levels of immunohistochemical stains for keratin and 2 levels of hematoxylin-eosin (HE) stains on the first 3 negative lymph nodes). Results.—Hematoxylin-eosin staining identified 20 patients (23.8%) with sentinel node metastases. The remaining 64 negative patients (76.1%) were tumor free on sentinel lymph n...

Different patterns of cytokeratin expression in Barrett's esophagus--what is beyond?

Barrett's esophagus (BE) was recently defined by the presence of metaplastic intestinal mucosa (specialized columnar epithelium) in the distal esophagus. However, different epithelial types that were classified by histological criteria occur at the gastro-esophageal region. The purpose of this study was to evaluate the expression of different subtypes of cytokeratins in Barrett's mucosa (BM) and to contribute to the discussion about the significance of cytokeratin expression patterns within the gastro-esophageal junction. Immunohistochemical detection of a wide spectrum of cytokeratins (CK7, CK10, CK19, CK20, CKHW, CK116 and CKAE1/AE3) was performed in bioptic samples obtained from 10 adults with BE and in nine samples of gastric mucosa from the same patients. Cytokeratin immunoreactivity of epithelial cells appearing in BM was particularly dependent on the differentiation degree of these cells. Less differentiated cells were positive for CK7 and CK10, as were the cells of the necks of gastric mucosa and the ducts of esophageal glands. In contrast, differentiated goblet cells showed only weak or negative immunoreactivity for CK7 and CK10. CK20 was positive predominantly in superficial parts of BM. Immunostaining with antibodies detecting a wider spectrum of cytokeratins (CK116, CKAE1/AE3) revealed prominent irregularities, particularly regarding the intensity of immunoreaction. BM showed only weakly positive staining for high molecular weight keratins. Our findings suggest that the mode of CK expression in BM is closely related to the differentiation degree of cells forming BM, and that the cytokeratin inmmunoreactivity pattern in BM is similar to that in the cells forming the necks of gastric glands and ducts of esophageal glands. However, it differs from squamous epithelium of esophageal mucosa.

Spitz nevus of the tongue with pseudoepitheliomatous hyperplasia: report of three cases of a pseudomalignant condition.

Three cases of Spitz nevus of the tongue associated with pseudoepitheliomatous hyperplasia are reported: two occurring in children and one in an adult. The location at an unusual site and the complex pattern resulting from the intimate admixture of the neoplastic melanocytic component and the hyperplastic keratinocytic component led in each case to consider diagnoses such as malignant melanoma and invasive squamous cell carcinoma. Staining for S-100 protein and keratin was useful to identify and separate the two components. Spitz nevus of the tongue carries some intriguing similarities with granular cell tumor, suggesting a possible histogenetic and pathogenetic relationship.

Keratin expression in human tissues and neoplasms.

Keratin expression in human tissues and neoplasms Keratin filaments constitute type I and type II intermediate filaments (IFs), with at least 20 subtypes named keratin 1-20. Since certain keratin subtypes are only expressed in some normal human tissues but not others, and vice versa, various tissues have been subclassified according to the pattern of keratin staining. Simple epithelia generally express the simple epithelial keratins 7, 18, 19, and 20, while complex epithelia express complex epithelial keratins 5/6, 10, 14, and 15. When an epithelium undergoes malignant transformation, its keratin profile usually remains constant. The constitution and expression patterns of keratin filaments in human epithelial neoplasms are complex and often distinctive. In this article, we first briefly review the molecular and cell biology of keratin filaments. We then focus on the expression patterns of keratin filaments in various human neoplasms.

Differential effects of olfactory toxicants on olfactory regeneration.

The aim was to study the long-term response in the olfactory mucosa of NMRI mice after exposure to the olfactory toxicants dichlobenil (a herbicide) or methimazole (an antithyroid drug). Three and six months after exposure to dichlobenil (2x or 1 x 25 mg/kg i.p.), the dorsomedial part of the olfactory region showed a respiratory metaplasia with abundant invaginations and a fibrotic lamina propria. In contrast, 3 months after exposure to a toxic dose of methimazole (2 x 50 mg/kg i.p.), the olfactory neuroepithelium and lamina propria had been restored. To study the regenerative events, we used an antibody derived against growth-associated protein 43 (GAP-43), which stains immature neurons. To study epithelial differentiation and horizontal basal cells (HBCs) we used an antibody derived against some cytokeratins. Two weeks after methimazole treatment, there was a marked increase of GAP-43-stained cells in the whole olfactory region, which correlated with the observed regeneration at that time. Two weeks after dichlobenil treatment, the damaged atypical epithelium in the olfactory region showed a distinct keratin staining of basal and columnar cells whereas GAP-43-stained cells were not found. Despite a transient increase of GAP-43-stained cells in the border zone between damaged and undamaged olfactory mucosa, an expansion of a normal neuroepithelium into the damaged olfactory region was not detected in the dichlobenil-treated mice. An intact lamina propria is suggested as a prerequisite for repopulation of the neuroepithelium after toxicant-induced injury.

PURE RHABDOID TUMOR OF THE BLADDER

A 4-year-old girl presented with a single episode of painless macrohematuria. Physical examination was unremarkable. Abdominal ultrasonography and subsequent abdominopelvic computerized tomography demonstrated a localized lesion in the bladder. Cystoscopy revealed a discrete, wide based tumor in the bladder dome, which was confirmed on biopsy as embryonal rhabdomyosarcoma. The patient underwent partial cystectomy, removing the tumor with wide normal margins. Gross pathological examination of the specimen revealed a polypoid mass, measuring 1.8 1.6 2.4 cm., covered by an intact overlying mucosa. On microscopic examination the tumor infiltrated the full thickness of the bladder wall. However, the surgical margins were tumor-free. The specimen demonstrated monomorphous noncohesive large cells with peripherally displaced vesicular nuclei, prominent nucleoli and acidophilic cytoplasm containing typical cytoplasmic inclusion structures. Mitoses were abundant. Positive immunohistochemistry staining for vimentin, smooth muscle actin and epithelial membrane antigen characterized the tumor cells. On the other hand, staining for keratins (MNF116 and CK19), desmin, myoglobin, sarcomeric actin, glial fibrillary acidic protein, synaptophysin, S-100, chromogranin, CD68, MAC-387 and -1 antitripsin were negative. Electron microscopic examination showed the typical aggregates of whorled intermediate filaments that ranged in thickness from 6 to 10 nm. Cross striations, basal lamina and desmosomes were not seen. In view of the typical incision bodies, distinctive immunohistochemistry stainings and the differentiative electron microscopic findings rhabdomyosarcoma was ruled out and rhabdoid tumor was diagnosed. Adjuvant chemotherapy included 8 courses of vincristine, ifosfamide and etoposide followed by 4 courses of vincristine, actinomycin D and cyclophosphamide and 4 courses of vincristine, cyclophosphamide and doxorubicin. At 2-year followup repeat computerized tomography and cystoscopy with the patient under anesthesia demonstrated no evidence of recurrent disease and the patient is continent with a good capacity bladder.

Expression of thyroid transcription factor-1 and other markers in sclerosing hemangioma of the lung.

Sclerosing hemangioma of the lung is well characterized histologically, but the line of differentiation expressed by the tumor cells has been unclear. Despite the implication by its name of a vascular neoplasm, sclerosing hemangioma is considered by most authorities to be an epithelial tumor, possibly related to the pulmonary epithelium. To determine the line of differentiation of the tumor cells with immunohistochemistry and to review the related literature. Nine cases of histologically typical pulmonary sclerosing hemangioma were studied with pan-epithelial (epithelial membrane antigen [EMA] and CAM 5.2), endothelial (CD31), neuroendocrine (chromogranin A), and pulmonary epithelial markers (thyroid transcription factor-1 and PE10). Staining intensity was separately evaluated in the pale cells of the solid areas and the cells lining the papillary structures. Both cell types were positive for thyroid transcription factor-1 and EMA in all cases (100%). Thyroid transcription factor-1 showed diffuse strong staining, and EMA staining varied from focal weak to diffuse strong. The pale cells showed focal staining for keratin (CAM 5.2) in 2 (28%) of 7 cases, and for PE10 in 5 (62%) of 8 cases. The papillary lining cells were at least focally positive with CAM 5.2 and PE10 in all cases (100%). Reactions for chromogranin and CD31 were negative in both cell types in every case. The number of PE10- or CAM 5.2-positive papillary lining cells was less than the number of EMA-positive papillary lining cells. The uniform positivity for EMA is consistent with the notion that the tumor cells of sclerosing hemangioma are epithelial, and the strong thyroid transcription factor-1 positivity suggests differentiation toward pulmonary epithelium. The papillary lining cells expressing EMA as well as PE10 or CAM 5.2 likely represent entrapped metaplastic alveolar epithelium, whereas the papillary lining cells expressing only EMA more likely constitute true neoplastic cells similar to those in the solid areas.

Phenotypic analyses of limbal epithelial cell cultures derived from donor corneoscleral rims.

Grafted cultures of limbal epithelial cells aid repair of the corneal epithelium, but their phenotype is unclear. In this study, the phenotype of cultures that were similar in age to those used clinically were analysed. Limbal epithelial cells were isolated from donor corneoscleral rims and grown in various media, including those designed for keratinocytes. Successful cultures in each medium developed predominantly small (10 microm) tightly packed cells. Immunocytochemistry and western blotting revealed expression of keratins 3, 14 and 19. Expression of these keratins in situ was confirmed by immunohistochemistry. Basal limbal epithelial cells were positive for keratins 14 and 19, and suprabasal cells were positive for keratin 3. However intense staining for keratin 14 was also observed at the inner cut edge of corneoscleral rims. These findings demonstrate the potential importance of keratins 14 and 19 as markers of epithelial cell differentiation in the human cornea.

Bovine mastitis due to Prototheca zopfii: clinical, epidemiological and pathological aspects in a Brazilian dairy herd.

The clinical, epidemiological and pathological aspects of protothecal mastitis in a Brazilian dairy herd are described. Prototheca zopfii infection was diagnosed in 11 of 121 milking cows. Clinical mastitis refractory to usual therapy was observed in 7 cows. Several environmental conditions conducive to the growth of Prototheca spp., such as wetness, muddiness and the presence of organic material, were present in the dairy. Improper milking practices and insanitary infusion of the intramammary antibiotics were also observed. Six cows with protothecal mastitis were slaughtered and the affected quarters of each cow were examined by histology and immunohistochemical staining for bovine keratin and P. zopfii. The histological lesions were characterized by interstitial infiltrates of macrophages, plasma cells and lymphocytes; algae were seen in the alveolar lumen and interstitium. The lack of a positive reaction with an antiserum against bovine keratin in the mammary alveolar epithelial layer in some affected areas suggests destruction of milk-producing tissues, which may be related to the low milk production observed. The algal organisms stained positively with a polyclonal antibody against P. zopfii.

Histopathological characteristics of five clinical types of equine sarcoid

The purpose of this study was to determine the characteristics of occult, verrucous, fibroblastic, nodular and mixed equine sarcoids. Ten tumours of each type were examined histologically and analysed for the presence of bovine papilloma virus (BPV)- DNA. All tumours were positive for BPV - DNA and showed an increased density of dermal fibroblasts. Epidermal hyperplasia, hyperkeratosis, rete peg and ‘picket fence’ formation were only found consistently in the verrucous and mixed types and were often not present in occult and nodular sarcoids. Immunohistochemical staining for Keratins 10 and 16, Ki67 and p53 showed no important differences between the clinical types.It can be concluded that the presence of BPV - DNA and the increased density of dermal fibroblasts were the only common characteristics for all sarcoids of the different clinical types. The presence of other microscopic alterations was variable but could not be used in the differentiation of the clinical types based on histology.

Cytokeratin Staining in Merkel Cell Carcinoma: An Immunohistochemical Study of Cytokeratins 5/6, 7, 17, and 20

Merkel cell carcinoma is an aggressive cutaneous neoplasm with neuroendocrine differentiation that carries a poor prognosis. Its homogeneous morphology is easily confused with lymphoma, leukemia, metastatic small cell carcinoma, and poorly differentiated cutaneous malignancies. Histopathologic diagnosis frequently requires support by immunohistochemistry. The authors investigated cytokeratins (CKs) 5/6, 7, 17, and 20 staining in paraffin sections of 26 Merkel cell carcinomas to expand the knowledge of the CK staining profile of this entity. Reactivity with anti-CK 20 was demonstrated in 23 of 26 Merkel cell carcinomas (88%). All three CK 20–negative tumors showed punctate staining with anti-keratin CAM5.2. Six of 26 tumors (23%) were positive for CK 7, a finding not previously reported. The staining patterns for both CKs 20 and 7 ranged from punctate (perinuclear) to localized (confined to half of the cytoplasm) to diffuse. Punctate CK 20 staining was seen in 17 of 26 cases but was the predominant pattern in only 10 cases. Antibodies to CKs 5/6 and 17 were each negative in the 13 cases for which these stains were performed. Both the positive and negative elements of the CK profile of this distinctive neoplasm provide additional useful diagnostic information for the differential diagnosis between Merkel cell carcinoma and other carcinomas that may simulate it. The authors note that the classically described perinuclear dotlike keratin staining pattern is not universally seen with CK 20 and that CK 7 staining may be seen in a subset of Merkel cell carcinomas.

Cytokeratin Staining in Merkel Cell Carcinoma: An Immunohistochemical Study of Cytokeratins 5/6, 7, 17, and 20

Merkel cell carcinoma is an aggressive cutaneous neoplasm with neuroendocrine differentiation that carries a poor prognosis. Its homogeneous morphology is easily confused with lymphoma, leukemia, metastatic small cell carcinoma, and poorly differentiated cutaneous malignancies. Histopathologic diagnosis frequently requires support by immunohistochemistry. The authors investigated cytokeratins (CKs) 5/6, 7, 17, and 20 staining in paraffin sections of 26 Merkel cell carcinomas to expand the knowledge of the CK staining profile of this entity. Reactivity with anti-CK 20 was demonstrated in 23 of 26 Merkel cell carcinomas (88%). All three CK 20-negative tumors showed punctate staining with anti-keratin CAM5.2. Six of 26 tumors (23%) were positive for CK 7, a finding not previously reported. The staining patterns for both CKs 20 and 7 ranged from punctate (perinuclear) to localized (confined to half of the cytoplasm) to diffuse. Punctate CK 20 staining was seen in 17 of 26 cases but was the predominant pattern in only 10 cases. Antibodies to CKs 5/6 and 17 were each negative in the 13 cases for which these stains were performed. Both the positive and negative elements of the CK profile of this distinctive neoplasm provide additional useful diagnostic information for the differential diagnosis between Merkel cell carcinoma and other carcinomas that may simulate it. The authors note that the classically described perinuclear dotlike keratin staining pattern is not universally seen with CK 20 and that CK 7 staining may be seen in a subset of Merkel cell carcinomas.

Atypical cystic lobule of the breast: An early stage of low-grade ductal carcinomain-situ

The authors describe the characteristics of atypical cystic lobules (ACLs), which represent a step in the formation of low-grade ductal carcinoma in-situ. The authors define ACLs as a proliferation of luminal cells showing low-grade cytological atypia without architectural atypia. ACLs were compared with conventional hyperplasia, low-grade ductal carcinoma in-situ, and lobular neoplasia. 1) In about 40% of the cases, atypical cystic lobules merged with fully established micropapillary/cribriform ductal carcinoma in-situ. 2) Immunohistochemical staining for hormone receptors, keratin nineteen, and cyclin D1 revealed that atypical cystic lobules demonstrate a consistent immunophenotype, which differs from that of normal lobules and benign lesions and matches the one of low-grade ductal carcinoma in-situ. 3) ACLs are sometimes calcified. Osteopontin-positive histiocytes infiltrated all Kossa-positive (type II microcalcification) cribriform and comedo-type carcinomas and ACLs. The similarities in cytological and immunohistochemical features, the close proximity of the two types of proliferation, and the similarities with respect to calcification suggest that atypical cystic lobules represent an early stage in the formation of certain types of low-grade ductal carcinoma in-situ.

The separation of benign and malignant mesothelial proliferations.

The separation of benign from malignant mesothelial proliferations has emerged as a major problem in the pathology of the serosal membranes. For both epithelial and spindle cell mesothelial processes, true stromal invasion is the most accurate indicator of malignancy, but stromal invasion is often difficult to assess, especially in small biopsies. In the pleural cavity, deep penetration of a thickened and fibrotic pleura or penetration of mesothelial cells into the fat of the chest wall are good indicators of malignancy; however, superficial entrapment of mesothelial cells and glands by organizing effusions is common in benign reactions and needs to be distinguished from invasion. In the peritoneal cavity, invasion of fat or of organ walls is again the most reliable indicator of malignancy, but entrapment of benign cells in organizing granulation tissue or between fat lobules is frequent and confusing. Proliferations confined to the pleural or peritoneal space, particularly linear arrays of atypical mesothelial cells on the free surface, should not be called malignant in the absence of unequivocal invasion. Cytologic atypia is often not helpful in separating benign from malignant reactions, because benign processes are commonly atypical and mesotheliomas are often deceptively monotonous. Densely packed mesothelial cells within the pleural space are frequent in benign reactions, but densely packed mesothelial cells within the stroma favor a diagnosis of malignancy. Organizing effusions (fibrous pleurisy) typically show zonation with high cellularity and cytologic atypia toward the pleural space and increasing fibrosis with decreasing cellularity and lesser atypia toward the chest wall, whereas sarcomatous (including desmoplastic) mesotheliomas do not demonstrate this type of zonation. Elongated capillaries perpendicular to the pleural surface are seen in organizing effusions but are not a feature of sarcomatous mesotheliomas. The combination of a paucicellular storiform pattern, plus invasion of the stroma (including fat and adjacent tissues), or bland necrosis, overtly sarcomatous foci, or distant metastases, is required for the diagnosis of desmoplastic mesothelioma. Necrosis is usually a sign of malignancy but is occasionally seen in benign mesothelial reactions. Keratin staining is useful in indicating the distribution of mesothelial cells, and particularly in demonstrating penetration of mesothelial cells into the stroma or adjacent structures, but is of no help in separating benign and malignant proliferations because both are keratin-positive. Although both p53 and EMA staining have been proposed as markers of mesothelial malignancy, in our experience they are not helpful for the individual case.

Pseudohyperplastic prostatic adenocarcinoma on needle biopsy and simple prostatectomy.

Prostatic adenocarcinoma resembling benign hyperplastic glands architecturally is a recently recognized entity. In the only prior study on this entity, 100 needle biopsies were studied and only two contained carcinoma with pseudohyperplastic features, which occupied a small percentage of the cancer. The current study investigates histologic attributes of pseudohyperplastic prostatic adenocarcinoma on needle biopsy and simple prostatectomy in which the pseudohyperplastic regions represent the majority of the cancer. The authors reviewed outside cases received in consultation by one of the authors (J.I.E.) and the surgical pathology files of Johns Hopkins Hospital from January 1991 to August 1998 and identified 20 cases of needle biopsy and simple prostatectomy in which > or =60% of the cancer had benign architectural features. The majority (19 of 20) were consult cases. Of the 20 cases studied, 16 were needle biopsies, two were transurethral resections of the prostate, and two were enucleations. Cancer involved one core in 75% of the needle biopsies. In 13 of the 20 cases (65%), > or =90% of the cancer had pseudohyperplastic features. Benign features included papillary infoldings in all cases, large atypical glands in 95% of cases, branching in 45% of cases, and corpora amylacea in 20% of cases. The extent of pseudohyperplastic cancer ranged from 1.0 to 10.0 mm (average, 3.7 mm). Within the pseudohyperplastic foci, features helpful in establishing a malignant diagnosis were nuclear enlargement in 95% of cases, pink amorphous secretions in 70% of cases, occasional to frequent nucleoli in 45% of cases, and crystalloids in 45% of cases. Other features associated with malignancy (mitoses, blue-tinged mucin, adjacent high-grade prostatic intraepithelial neoplasia, and perineural invasion) were seen infrequently. Immunohistochemical stains for high-molecular weight keratin showed an absence of basal cells in the pseudohyperplastic areas in all 20 cases, confirming the diagnosis of cancer. It is critical to recognize pseudohyperplastic prostatic adenocarcinoma and the features needed to establish a malignant diagnosis so these carcinomas are not misdiagnosed as benign.

CORRELATION OF SERUM PROSTATE SPECIFIC ANTIGEN AND QUANTITATIVE IMMUNOHISTOCHEMISTRY

Serum prostate specific antigen (PSA) in patients with prostate carcinoma is influenced by prostate size, transition zone volume, and tumor differentiation and volume. Immunohistochemistry studies have demonstrated an inverse correlation between PSA staining intensity and tumor grade, yet to our knowledge tissue expression of PSA has never been correlated with serum PSA. In 47 radical prostatectomy cases serum PSA was corrected for gland size and tumor volume. Standard immunohistochemistry staining techniques were applied to specimens using monoclonal antibodies to PSA and cytokeratin CAM5.2. Color images of PSA and CAM5.2 immunohistochemistry stained slides were digitally acquired and analyzed using a standard image analysis system. Representative tumor foci in each slide were imaged with a 20x objective and 10x eyepiece. Staining extent and intensity of the tumor epithelium were measured, and stromal elements and luminal areas were excluded from analysis. For each case quantitative PSA staining intensity was expressed relative to keratin staining in adjacent benign epithelium. Gland volume and tumor volume independently correlated with serum PSA. Furthermore, tissue PSA intensity inversely correlated with histological grade of the tumor (p <0.00001). After gland size, tumor volume and grade were considered, corrected quantitative tissue PSA intensity did not significantly correlate with corrected serum PSA. Immunohistochemistry expression of tissue PSA in prostate carcinoma cannot be used to explain variations in serum PSA. This discrepancy may relate to differences between the amount of PSA produced by prostatic tumors and the amount secreted, and/or the sensitivity of detecting various tissue isoforms of PSA with immunohistochemistry.

SOLITARY FIBROUS TUMOR PRESENTING AS PERIRENAL MASS ASSOCIATED WITH HYPOGLYCEMIA

Solitary fibrous tumor is an uncommon mesenchymal lesion, seldom associated with hypoglycemia and rarely presents as a perirenal mass. We describe a perirenal solitary fibrous tumor presenting as a renal mass associated with recurrent hypoglycemic events that resolved after nephrectomy. We discuss the diagnosis, endocrine evaluation and mechanism of the associated hypoglycemia of the solitary fibrous tumor. CASE REPORT An 82-year-old patient presented with episodes of severe symptomatic hypoglycemia without other symptoms or any relevant medical history. Physical examination revealed a left upper quadrant abdominal mass. Computerized tomography of the abdomen showed a localized solid left renal mass 13 cm. in diameter. Endocrine evaluation during a hypoglycemic episode revealed undetected levels of serum insulin and C peptide. Somatostatin scan did not support the preliminary diagnosis of an insulinoma. A 72-hour fasting test was associated with a decrease in blood glucose level to a nadir of 30 mg./dl. (normal 70 to 115) associated with severe confusion. Blood samples taken concomitantly disclosed suppressed levels of insulin, C peptide, growth hormone and insulin-like growth factor without ketonemia. Cortisol levels were high. These findings raised the possibility of a nonislet cell tumor hypoglycemia. The patient underwent radical nephrectomy. During exploration the mass was identified as a perirenal tumor adherent to the renal capsule. Convalescence was uneventful with no further episodes of hypoglycemia after 24 months. Repeat 12-hour fasting test at 3 weeks postoperatively did not indicate hypoglycemia (serum blood glucose was 104 mg./dl.). Plasma insulin, C peptide, growth hormone and insulin-like growth factor-1 increased to normal levels. Pathological examination revealed a large 8 3 13.5 3 14.5 cm. encapsulated mass in the perirenal adipose tissue (fig. 1). The mass had no connection to the renal capsule. On light microscopy the tumor was composed of uniform spindle cells forming a solid pattern with some areas showing abundant deposition of collagen and only a few mitoses (fig. 2). Immunohistochemical studies revealed immunoreactivity for CD 34 and vimentin. Stains for S-100 protein, keratin, MNF 116, desmin, a-1 muscle, CD 68 and factor VIII were negative. These features are consistent with the diagnosis of perirenal benign solitary fibrous tumor.

Primary alveolar soft part sarcoma of bone.

Alveolar soft part sarcoma is a distinct, rare soft tissue tumour occurring primarily within the skeletal muscles or musculofascial planes in young adults. Primary involvement of bone is extremely rare. We report on six patients with alveolar soft part sarcoma occurring primarily in bone. Thorough clinical and radiographic examinations were done to rule out any other primary site. The patients were four women and two men aged 17-35 years (mean, 24.5 years). The primary site of the tumour was the femur in three patients, the ilium in one and the fibula in two. In one of the patients with fibular involvement, the tibia was also involved by direct extension. Of the long bone lesions, three were centred in the metaphysis and one in the diaphysis. Radiographically, all of the lesions demonstrated an osteolytic pattern of bone destruction with ill-defined margins and a wide zone of transition between the lesion and adjacent normal bone. Microscopically, all tumours showed the typical histological pattern of alveolar soft part sarcoma. Diastase-resistant, periodic acid-Schiff-positive crystalline structures were identified within the cytoplasm and confirmed ultrastructurally. Immunohistochemically, a keratin stain was negative in all cases; there was positive staining for MyoD1 in the cytoplasm but not the nuclei. Distant metastasis developed in four patients; one died. Alveolar soft part sarcoma arising in bone is extraordinarily rare but should be considered in the differential diagnosis of metastatic hypernephroma in a young patient.

The effect of ruby laser light on cellular proliferation of epidermal cells.

In ruby laser-assisted hair removal, microscopic damage is often seen in the basal epidermal cells, where melanosomes are concentrated. It is not known whether this treatment leads to cellular hyperproliferation. It was the aim of this study to investigate this. Ten white patients were treated with the Chromos 694-nm Depilation Ruby Laser, and biopsies taken before and after treatments to assess the presence of cell hyperproliferation, which normally accompanies epidermal damage, with immunohistochemical staining of keratin 16 and Ki67. No evidence of cell hyperproliferation was seen in all specimens examined after ruby laser irradiation. The authors conclude that despite the possible microscopic damages seen in the basal epidermis after laser hair removal, there is no evidence of cellular hyperproliferation. This is in contrast to ultraviolet-irradiated cell damage, in which increased basal cell turnover is seen.