Papillary renal cell neoplasm with reverse polarity: A new subtype of renal tumour with favorable prognosis

INTRODUCTION

Papillary renal cell neoplasm with reverse polarity (PRNRP) has recently been recognized as an entity separate from the traditional classification of papillary renal cell carcinomas, due to its specific histopathological, immunophenotypic and molecular characteristics, as well as its indolent behavior.

MATERIAL AND METHODS

We provide 6 new cases and a review of the literature published until the present time, which comprises a total number of 104 cases.

RESULTS

Our PRNRP cases correspond to 5 men and one woman aged between 47 and 91 years. In 5 of the 6 cases, the PRNRP was an incidental finding in nephrectomy specimens. Nephrectomy had been indicated due to the presence of another renal tumor, except for one case, in which surgical intervention was indicated due to PRNRP. Our cases present mass sizes between 2 and 13 mm, as well as papillary histology with a monolayered lining of eosinophilic cells with low-grade nuclei in apical location. Immunohistochemically, they show a constant positivity for GATA3 and negativity for vimentin. KRAS mutations were identified in 50% of our cases. After a follow-up ranging between one and 60 months, 5 of the cases were still alive without recurrences or metastases, and one died from urothelial carcinoma.

CONCLUSIONS

Our cases agree with the clinical and pathological characteristics described in the PRNRP cases published to date. With the present study, we provide the first series of national cases corroborating the existence of well-defined and constant diagnostic criteria that allow PRNRP to be considered as a distinctive entity.

Interobserver reproducibility of a grading system for chromophobe renal cell carcinoma

OBJECTIVES

To evaluate interobserver reproducibility of a grading system proposed by Paner et al. for chromophobe renal cell carcinoma.

MATERIAL AND METHODS

After selecting 23 cases of chromophobe renal cell carcinoma from the Xeral-Cíes Hospital, Meixoeiro Hospital and POVISA Hospital from the last 15 years, an informative meeting on the Paner et al. grading system criteria was held. After, the participating pathologists applied the system to each case, evaluating one slide selected. Kappa index for interobserver reproducibility was calculated, and it was classified according to the Landis and Koch scale.

RESULTS

The grading distribution was similar for most of the 6 participating observers, with grade 1 predominance. The remaining 2 observers considered a relatively higher proportion of grade 2. Kappa index values ranged from 0.136 to 0.674, with a discrete-moderate reproducibility index predominance (0.21-0.60). Highest Kappa value (0.674) was obtained between the most novel and the most expert interobservers. The lowest Kappa value was obtained among the most veteran pathologists (0.136).

CONCLUSIONS

Interobserver reproducibility for chromophobe renal cell carcinoma is discrete-moderate in our institutions when the novel grade proposed by Paner et al. is used. Labeling of grades 1 and 2 is not homogeneous among 6 participating observers. While awaiting a grading consensus on a new classification by the scientific societies, we consider that the routine use of a grading system for chromophobe renal cell carcinoma should not be used.

Livedoid vasculopathy and recurrent thrombosis in a patient with lupus: seronegative antiphospholipid syndrome?

Livedoid vasculopathy is a rare condition which predominantly affects young women. It is characterized by intense painful purpuric maculae in the legs, ankles and feet, due to thrombosis of the small and medium-sized dermal vessels, in the absence of vasculitis. Livedoid vasculopathy has been frequently associated with hypercoagulable states and antiphospholipid syndrome. We describe a 34-year-old White woman suffering from systemic lupus erythematosus, livedo reticularis, haemolytic anaemia, severe thrombocytopenia and recurrent venous thrombosis who was admitted to the hospital for extremely painful purpuric lesions in her lower limbs. The clinical and histological findings were diagnostic of livedoid vasculopathy. Once the initial sub-therapeutic international normalized ratio levels were corrected, livedoid vasculopathy did not recur. Tests for antiphospholipid antibodies were repeatedly negative. This case, the first reported of livedoid vasculopathy in a patient with seronegative antiphospholipid syndrome and systemic lupus erythematosus, draws attention to livedoid vasculopathy, a thrombotic dermopathy that may be under-diagnosed in patients with antiphospholipid syndrome.

[Conjunctival inclusion cyst after strabismus surgery by hang-back recession]

CASE REPORT

A 24-year-old woman, with a history of infantile esotropia and DVD operated on in infancy, had strabismus surgery performed by us. Four months later she presented with a cystic lesion that recurred after drainage and medical treatment. Complete excision of the cystic lesion was therefore performed.

DISCUSSION

The epithelial cells implanted on the sclera at the time of the most recent surgery may have been the origin of inclusion cyst which developed after the strabismus surgery. This suggests a possible relationship with the scleral suture as the mechanism of cyst formation, independent of the muscle position. Complete excision is the recommended treatment for large cysts.

[Expression of CD10 and renal cell carcinoma marker in clear cell renal cell carcinoma: analysis on tissue arrays]

OBJECTIVES

CD10 and renal cell carcinoma (RCC) marker antibodies react against proteins of the epithelium of the renal proximal tubule, being expressed by renal cell carcinomas. The frequence and pattern of expression of both markers are analysed in a series of clear cell renal cell carcinomas.

METHOD

Two tissue arrays were used, which were composed of cylinders obtained with a 16G needle from 40 paraffin blocks that corresponded to clear cell renal cell carcinomas. The labeled streptavidin-biotin technique was performed (LSAB2, Dako) using CD10 and RCC monoclonal antibodies (Novocastra), testing different antigen retrieval methods for RCC. Immunoreactivity was evaluated as + (isolated cells or focal staining); ++ (moderate) and +++ (extense).

RESULTS

Thirty cases (75%) were positive for CD10: 12 +; 5 ++ and 13 +++. The best antigen retrieval method for RCC was a double enzyme digestion (trypsin + protease). Twenty cases (50%) were positive for RCC: 7 +; 5 ++ and 8 +++. Four cases out of the 20 immunoreactive for RCC were negative for CD10. The 16 remaining cases also expressed CD10.

CONCLUSIONS

CD10 and RCC are often expressed by clear cell renal cell carcinomas, and they may be useful markers to suggest a renal origin of carcinomas. RCC is less sensitive than CD10. Staining for both of them is usually focal, and thus sensitivity of these techniques decreases when small samples are investigated, such as tissue arrays. The antigen retrieval method is essential for RCC immunohistochemical detection, obtaining the best results with the use of proteolytic enzymes.

[Expression of cytokeratin 5 and calretinin in clear-cell renal cell carcinoma]

PURPOSE

Cytokeratin 5 (CK5) and calretinin have been useful in different studies as immunohistochemical markers suggestive of mesothelioma, and their expression is analyzed for the histological differential diagnosis with adenocarcinomas, specially when confronting with metastatic tumors of unknown origin. We have analyzed the expression of CK5 and calretinin in clear cell renal cell carcinoma.

METHODS

A series of 63 clear cell renal cell carcinomas was studied. 46 of these cases were embedded in two tissue arrays, and a second group, of 17 cases, was constituted by conventional paraffin blocks from high-grade tumors (grade 4 of Fuhrman). Immunohistochemical staining was performed with monoclonal antibodies against CK5 and calretinin, following the labeled sptreptavidin-biotin technique.

RESULTS

No positivity for calretinin was observed in any case, while CK5 was focally expressed, in an isolated group of cells, in 1 of the 63 cases (1,59%) which corresponded to a high-grade carcinoma (grade 4 of Fuhrman).

CONCLUSIONS

Expression of calretinin was not observed in clear cell renal cell carcinoma and positivity for CK5 occurred only in one case, in a very small proportion of tumor cells. Therefore, in practice, although the positivity for these markers cannot completely exclude renal cell carcinoma, this result is very rare in this tumor and other diagnostic posibilities should be considered.

[Spermatic cord mass as a manifestation of systemic vasculitis: a case report and review of the literature]

We report a case of necrotizing granulomatous vasculitis in the spermatic cord in a 35-year-old man with an antecedent of brain stroke 3 years before. The clinical manifestation was as a painless left scrotal mass. The diagnosis was established by histological examination of the spermatic cord. We discuss the physical findings, radiological features and pathological findings, reviewing the literature for previous similar cases.

Hobnail haemangioma associated with the menstrual cycle

We report the third case in the literature of a hobnail haemangioma with cyclic changes throughout the menstrual cycle in a 36-year-old woman, suggesting a hormonal basis for the variations in the tumour. This patient was under oral contraceptive treatment due to ovarian endometriosis, making the clinical diagnosis difficult.

Expresión de cdx2 en lesiones de vejiga urinaria y uretra

BACKGROUND

CDX1 and CDX2 are transcription factors involved in the development and maintenance of the intestinal epithelial cell. Expression of CDX2 has been reported in normal and metaplastic intestinal epithelium, and in those adenocarcinomas with that cellular origin. We have analyzed the expression of this marker in reactive and tumoral lesions arising in urinary bladder, urethra and urachus.

METHOD

CDX2 was investigated through immunohistochemistry on paraffin-embedded tissue, using the labelled streptavidin-biotin method (LSAB2, Dako) with a monoclonal antibody (CDX2-88, BioGenex).

RESULTS

Expression of CDX2 was observed in intestinal-type cistitis glandularis, intestinal metaplasia of urinary bladder, bladder adenocarcinoma, mucinous urothelial-type carcinoma of prostatic urethra and urachal mucinous carcinoma. CDX2 was not detected in normal urothelium and prostatic glandular epithelium, Von Brunn nests, typical-type cistitis glandularis, glandular adenosis and transitional carcinoma.

CONCLUSIONS

Lesions, both benign and malignant, with enteric-cell morphological features show positivity for CDX2. Expression of this marker is not organ-specific but is just related to a cellular phenotype. Reactivity for CDX2 in an adenocarcinoma can be consistent with an origin in urinary tract or urachus.

Renal smooth muscle tumor with features of lymphangioleiomyomatosis. Problems in histological diagnosis

A 44-year-old woman with left kidney tumor involving the perirenal and retroperitoneal lymph nodes is presented. Imaging findings including ultrasonography and computerized tomography showed renal and para-aortic masses and no features of lymphangioleiomyomatosis or angiomyolipoma were seen. The histopathological examination was considered as a renal smooth muscle tumor with features of lymphangioleiomyomatosis. Diagnosis considerations, particularly histopathological, immunohistochemical and hormonal studies are discussed and we comment the distinction of this case from the benign mesenchymal tumors.

Metastatic lobular breast carcinoma to an endometrial polyp diagnosed by hysteroscopic biopsy

BACKGROUND

Secondary tumors involving the uterus are rare, and most come from the close vicinity. Among non-gynecologic origins, breast tumors are the most frequent, being predominantly of the lobular carcinoma type.

CASE

A 69-year-old woman presented with metrorrhagia. The patient had been diagnosed 4 years before with infiltrating lobular breast carcinoma. Follow-up was uneventful. She underwent hysteroscopy with biopsy. An endometrial polyp was seen. Microscopically, small malignant cells diffusely infiltrated the endometrial stroma and surrounded the atrophic endometrial glands. Immunohistochemical studies confirmed the diagnosis of metastatic lobular breast carcinoma.

CONCLUSION

Although rare, breast tumors can metastasize to an endometrial polyp, even in the absence of other disseminations. Abnormal vaginal bleeding in a patient with known breast carcinoma can be the first sign of metastasis.

Expression of fibronectin and tenascin as a demonstration of vital reaction in rat skin and muscle

The efficiency of immunohistochemical techniques for the diagnosis of vitality of wounds decreases for lesions occurring fairly close to death. We analyzed the expression of fibronectin (FN) and tenascin (TN) in wounds inflicted in abdominal skin of 12 adult rats. An incised injury was made at 5, 10 or 15 min before death and another at 5 min after sacrifice, and collected after 45 min. Formalin-fixed paraffin-embedded sections from a total of 36 samples (mean 1.5 per wound) were immunostained following the streptABC technique. Microscopic examination revealed a reticular pattern staining in 18 out of 20 vital samples for FN, 16 out of 20 for TN, 2 out of 16 postmortem samples for FN and 3 out of 16 for TN. Intracellular staining of muscle fibres was observed in 7 out of 20 vital and 5 out of 16 postmortem samples. FN and TN were detected in most of the vital injuries but they are not completely specific. Postmortem staining occurred in a few cases probably related to a passive extravasation of these molecules from damaged blood vessels. Reactivity of muscle fibres occurs both in vital and postmortem lesions, and is not useful in the diagnosis of vitality.

[Hyperplasia of adrenal rests in the testicle: a rare cause of male infertility]

We report the case of a 37-year-old man with infertility caused by bilateral testicular masses secondary to congenital adrenal hyperplasia (21-hydroxylase deficiency). Testicular biopsy was done and its was initially interpreted as Leydig cell tumor but after clinical information was histologically reclassified as tumor of the adrenogenital syndrome. The differential diagnosis with Leydig cell tumor is discussed and it must be established through the clinical, biochemical, radiological and pathological features.

Immunohistochemical detection of fibronectin and tenascin in incised human skin injuries

Immunohistochemical detection of molecules involved in inflammatory reaction can be useful for the diagnosis of vitality in skin wounds. We studied the expression of fibronectin (FN) and tenascin (TN) in 58 human skin wounds (48 vital and 10 postmortem). The age of vital injuries ranged from 3 min to 8 h and postmortem specimens were collected after a postinfliction interval of 15-180 min. One hundred thirty-seven formalin-fixed paraffin-embedded sections (mean: 2.3 sections per case) were stained with each of two monoclonal antibodies against FN and TN using the streptABC technique. A reticular staining for FN in wound edge and dermis was observed in 50% of vital specimens versus 0% in postmortem cases. Immunoreactivity was reduced in 10 autolysed cases. FN positivity exclusively at the injury margin was observed in 39.4% of vital wounds and 10% of postmortem cases. TN was negative in all specimens. Vital and postmortem hemorrhage areas showed positivity for FN and TN. Due to its low sensitivity, immunohistochemical analysis of FN is useful for determining vitality only in a minority of cases. Different factors in everyday practice, including autolysis and technical problems often produce false negative reactions with the result that FN cannot be regarded as a reliable parameter of vitality. Positive reactions (network staining) are more valuable than negativity but are not pathognomonic. Both vital and postmortem hemorrhages show an enhanced positivity for FN and TN, thus impeding the diagnosis.

Demonstration of apoptosis in human skin injuries as an indicator of vital reaction

Demonstrating the vital character of an injury and estimation of the age are routine tasks in forensic pathology and although many different techniques have been applied to this problem none have been found to be completely satisfactory. Apoptosis, an active genetically controlled process, is the major mechanism by which homeostasis of a number of physiological systems in the body is regulated and changes in the rate following different kinds of stimuli have prompted us to test it as an indicator of vitality. We used an in situ end-labelling technique (Apop-Tag) in 30 human surgical skin injuries with age since injury ranging from 3 min to 8 h and found that apoptotic keratinocytes are found in over 50% of the cases with a post-infliction interval of at least 120 min. Apoptosis was not seen in injuries less than 120 min old or in normal skin, which was used as an external control. These results suggest that apoptosis could be a useful indicator for the intravital occurrence of injuries and could help to estimate the date of the skin injuries in some cases. The importance of strict technical control is stressed and the necessity of a complementary technique to confirm apoptosis is discussed.

[Auto-induced eosinophilic panniculitis: a diagnostic dilemma]

Eosinophilic panniculitis is characterized by a prominent infiltration of subcutaneous fat with eosinophils. The clinical spectrum of lesions that display pathologic changes of eosinophilic panniculitis is diverse, but nodular lesions are the most common. The factitial eosinophilic panniculitis are exceptional, show a pleomorphic pattern of findings and are associated with personality disorders. Its main challenge is to establish the correct diagnostic. We report an unusual case of factitial nodular febrile panniculitis of the left forearm and proximal arm in an 16 year-old girl. She admitted that the lesions were self-inflicted by autoinjection of several farming products as attempted suicide. We describe the clinical, radiological and histopathological features as well as the differential diagnosis of this type of panniculitis.