Kien T. Mai

Epithelioid cell variant of renal angiomyolipoma

Angiomyolipoma is considered by many authors to be a hamartoma, occurring in a sporadic form or in association with tuberous sclerosis. The lesion may be solitary or multicentric, and may involve extrarenal sites such as lymph nodes, liver or spleen. Almost always the clinical course is benign. Microscopically, the lesion consists of thick-walled blood vessels, smooth muscle in a poorly organized pattern, and mature adipose tissue in varying amounts. In spite of its characteristic microscopic appearance, the lesion may be mis-diagnosed as a sarcoma due to a large tumour size, cellular atypia, mitotic activity and tumoral necrosis. We report a case of angiomyolipoma consisting almost entirely of epithelioid cells, with numerous multinucleated tumour giant cells. The case mimicked renal cell carcinoma in both its clinical and pathological aspects.

A Comparative Study of Metastatic Renal Cell Carcinoma with Correlation to Subtype and Primary Tumor

Clear cell (CRCC), papillary (PRCC) and chromophobe (CHRC) renal cell carcinoma (RCC) are the three most frequent subtypes of RCC. The rate and distribution of their metastatic lesions have not been well documented. We compared metastatic RCC according to subtype and primary tumor characteristics to better understand their behavior and to aid in the diagnosis of metastatic RCC. Pathology reports and clinical charts related to 283 CRCC, 48 PRCC and 13 CHRCC, including their respective sarcomatoid variants, were reviewed. A hundred and thirty-seven CRCC, 5 PRCC and 1 CHRCC with metastases were identified. CRCC and non-CRCC (PRCC and CHRCC) had different patterns of metastasis and primary tumor growth. CRCC metastases were predominantly distributed in lungs, bone, brain, lymph nodes, and adrenal glands. The associated primary CRCC measured 1.5 to 15 cm, were of all grades and stages, and were often associated with invasion of small or large veins. Three PRCC had regional lymph node metastases, 1 PRCC had both regional and mediastinal lymph node metastases. Bone metastasis was present in 1 case each of PRCC and CHRCC. One PRCC with metastasis solely to regional nodes measured 4 cm. The other 4 cases of PRCC with regional lymph node and/or distant metastases as well as the CHRCC with distant metastases were greater than 8 cm in diameter. In metastasizing and non-metastasizing non-CRCC, invasion of small veins was rare and invasion of renal veins was not seen. We cannot comment with any certainty on the metastatic behavior of CHRCC. In our experience, PRCC tend to loco-regional invasion with lymph node spread. They have a low potential for vascular invasion and distant metastases that likely occur only at late stages of the disease. CRCC has a propensity for vascular invasion and may be associated with distant metastasis at an early stage. Therefore, metastatic RCC at a distant location are most likely to be of CRCC origin than PRCC origin.

Bilateral primary ovarian squamous cell carcinoma associated with human papilloma virus infection and vulvar and cervical intraepithelial neoplasia. A case report with review of the literature.

Primary squamous cell carcinoma of the ovary is rare. Most cases represent malignant transformation of ovarian teratomas. Other cases are associated with preexisting Brenner tumor or ovarian endometriosis. We report a primary ovarian squamous cell carcinoma in a 40-year-old woman. The patient had recurrent high-grade intraepithelial neoplasia of the vulva (VIN) and recurrent high-grade cervical intraepithelial neoplasia (CIN). Human papilloma virus (HPV) DNA 16/18 was identified in an in situ and invasive carcinoma in the left ovary; CIN and VIN were identified with in situ hybridization with biotinylated DNA probes. Review of the literature revealed nine cases of primary ovarian squamous cell carcinoma not associated with a preexisting ovarian lesion. Three cases were not associated with CIN and occurred in women who ranged in age from 64 to 90 years and did not have carcinoma in situ component. Six cases were associated with CIN, had a carcinoma in situ, and occurred in younger women ranging from 33 to 54 of age. Our case belonged to the latter category. This report raises the possible causal relationship of HPV with primary ovarian squamous carcinoma in the group of middle-aged patients with CIN.

Renal epithelioid angiomyolipoma: a study of six cases and a meta-analytic study. Development of criteria for screening the entity with prognostic significance

Aims:  Renal epithelioid angiomyolipoma (EAML) is only described in case reports or in multi‐institutional small series. The aim was to report cases seen at our institution and to perform a meta‐analysis based on a literature review.

Vascular myxolipoma (angiomyxolipoma) of the spermatic cord

We report a case of vascular myxolipoma of the spermatic cord occurring in a 32-year-old man. Clinically, the lesion was mobile and tender. Pathologically, the tumor was encapsulated and rubbery with a beige-yellow gelatinous cut surface. Microscopically, the lesion consisted of adipose tissue with extensive areas of myxoid change and an abundance of thin and thick-walled blood vessels. We consider this tumor a vascular type of myxolipoma and propose the term angiomyxolipoma. The lesion should be distinguished from liposarcoma and aggressive angiomyxoma, which have malignant or aggressive clinical course.

Ureteral response to the placement of metallic stents: an animal model.

Metallic self-expanding mesh stents are increasingly used in the urinary tract. Little is known about the histological reactions that such prostheses have on the surrounding tissue. The effects of self-expanded metallic stents in the histologically normal ureter were examined in four dogs. Three-mm. Gianturco-Roubin coronary artery stents were introduced into the distal left ureter after dilatation. Follow-up excretory urography, retrograde pyelograms and autopsy were performed on 2 dogs at 1 month and on 2 dogs at 6 months. In all 4 dogs, the ureters remained patent. Histologic examination of the ureter showed that the stents had not become incorporated within the wall of the ureter. Reactive changes seen in the epithelium included penetration of both epithelium and submucosa between the wire struts and areas of fibrosis in the submucosal layer. The use of metallic stents in histologically normal ureters may be limited in the long term by this inflammatory response.

Incidental Prostatic Adenocarcinomas and Putative Premalignant Lesions in TURP Specimens Collected Before and After the Introduction of Prostrate-Specific Antigen Screening

BACKGROUND Since the introduction of prostate-specific antigen (PSA) screening for the detection of prostatic adenocarcinoma (PCA), there has been an increase in the incidence of stage T1c PCA. The purpose of this study was to compare the frequency of incidental PCA found in transurethral resection of prostate (TURP) specimens for a 14-month period during 1989-1990 (before PSA screening was available) with the incidence of PCA for a 32-month period during 1997-1999 (after PSA screening became available). DESIGN Consecutive TURP specimens from the 2 time periods were reviewed to identify incidental PCA, prostatic intraepithelial neoplasia (PIN), and atypical adenomatous hyperplasia (AAH). Cases of TURP for palliative treatment of known advanced PCA were excluded from the study. All TURP specimens were fixed in 10% buffered formalin and were processed according to the same protocol. RESULTS We reviewed 533 and 449 TURP specimens for the time periods 1989-1990 and 1997-1999, respectively. Comparison of the results for these 2 time periods revealed that the combined prevalence of T1a and T1b PCA decreased over time from 12.9% to 8.0% (P =.06) with the introduction of PSA screening. A new group of T1c PCA was established in the post-PSA screening period of 1997-1999. There were no statistically significant differences in the incidences of T1a PCA, PIN, and AAH in TURP specimens for the 2 time periods. CONCLUSION The decreased incidence of T1b PCA in TURP specimens for the 1997-1999 period represents a shift in PCA staging. Some PCAs previously staged as T1b are now staged as T2 carcinomas, as a result of PSA screening and earlier clinical detection. The introduction of PSA screening has had no influence on the incidence of T1a PCA, PIN, or AAH in TURP specimens.

Oncocytic papillary renal cell carcinoma with solid architecture : Mimic of renal oncocytoma

Papillary renal cell carcinoma (PRCC) can display extensive areas of solid and non‐papillary architecture and extensive areas with oncocytic cytoplasm. Eleven oncocytic renal cell neoplasms (ORCN) with histopathological features posing a diagnostic problem between renal cell carcinoma (RCC) with oncocytic features and renal oncocytoma (RO) were identified. The neoplasms were well circumscribed or encapsulated tumors with solid and diffuse growth pattern. Very occasional papillae were seen in four and tumoral necrosis in two of 11. Six ORCN displayed a CD117+/progesterone receptor (PR)+ immunophenotype (feature shared by RO) and five tumors displayed a CD117–/PR– immunophenotype (feature shared by RCC). The CD117–/PR– ORCN also displayed α‐methylacyl‐coenzyme A racemase and RCC antigen reactivity as well as varying reactivity for cytokeratin 7, vimentin and CD10 (features of oncocytic PRCC). These five cases had tumor sizes ranging from 1 to 6 cm. Two patients in the latter group developed progression of the disease with metastases. In conclusion, oncocytic PRCC with solid architecture is a rare type of RCC. The carcinoma often poses differential diagnostic problems with RO and has similar immunohistochemical properties to the common type of PRCC. Cytogenetic and molecular studies have not been performed yet for this variant of RCC.

Endometrioid adenocarcinoma of the uterus with a minimal deviation invasive pattern

Aims:  Minimal deviation adenocarcinoma of endometrioid type is a rare pathological entity. We describe a variant of typical endometrioid adenocarcinoma associated with minimal deviation adenocarcinoma of endometrioid type.

Fine needle aspiration biopsy of epithelioid angiomyolipoma. A case report.

BACKGROUND Epithelioid angiomyolipoma (AMYL) is a variant of angiomyolipoma characterized by sheets of epithelioid cells that may mimic renal cell carcinoma. This is the first report describing the fine needle aspiration biopsy features of this lesion. CASE A 47-year-old man with a history of epithelioid angiomyolipoma of the kidney treated with nephrectomy nine months previously presented with a recurrent retroperitoneal mass and multiple nodular liver lesions. Fine needle aspiration biopsy of one of the liver lesions showed fragments and sheets of noncohesive epithelioid cells with thin cytoplasm, markedly atypical nuclei, and scattered bizarre and multinucleated forms. The epithelioid cells focally expressed HMB-45 and were nonimmunoreactive, with epithelial markers. CONCLUSION Epithelioid AMYL may pose differential diagnostic problems with high grade carcinoma, especially renal cell, hepatocellular and metastatic carcinoma. An awareness of this entity and its characteristic cytologic features and immunoreactivity with HMB-45 is helpful in its identification.