Search

Renal angiomyolipoma is a benign neoplasm composed of variable proportions of blood vessels, smooth muscle, and adipose tissue. Smooth muscle, adipose tissue, blood vessels, and adjacent normal kidney tissue were separately microdissected from sections prepared from formalin-fixed, paraffin-processed tissues from angiomyolipomas from 18 women. X chromosome inactivation analysis using the methylation pattern at exon 1 of the human androgen receptor gene on chromosome Xq11-12 was used to study the clonal origin of each component. Nonrandom inactivation of X chromosomes was found in six of the 15 informative tumors. The smooth muscle and adipose tissue showed differing patterns of nonrandom inactivation of X chromosomes in five angiomyolipomas and the same pattern of nonrandom inactivation of X chromosomes in one. Samples from the blood vessels showed random inactivation of X chromosomes in all informative cases. Our data showed that the adipose tissue and smooth muscle cells of renal angiomyolipoma are both monoclonal but may arise independently. The coexistence of tumor subclones with morphologic heterogeneity can lead to the formation of a clinically detectable tumor.

It is controversial if the rare dermoid cyst of the testis should be classified as a variant of mature teratoma or separately. The spectrum of findings is also ill defined, as is the relationship of dermoid cyst to intratubular germ cell neoplasia of the unclassified type (IGCNU). This study therefore reports the findings in five testicular dermoid cysts that occurred in five patients, 17-42 years of age, who presented with testicular masses. Four lesions consisted of a keratin-filled cyst with a thickened wall, whereas one had islands of "shadow" squamous epithelial cells with superimposed calcification and ossification (pilomatrixoma-like variant). Hair was identified grossly in two cases. On microscopic examination, four tumors had hair follicles with sebaceous glands showing a typical, cutaneous-type orientation to an epidermal surface, although no hair shafts were present in two. In addition, the fibrous wall contained smooth muscle bundles (all tumors) and eccrine or apocrine sweat glands (4 tumors). In some cases there were also glands lined by ciliated epithelium (4 tumors, including the pilomatrixoma-like variant), intestinal mucosa (1 tumor), and bone (2 tumors). There was no cytologic atypia or apparent mitotic activity, and no case had IGCNU in the seminiferous tubules. All patients were clinical stage I and were treated by orchiectomy without adjuvant therapy. All were well on follow-up from 1.5 to 9.5 years later. This study supports that dermoid cyst may have noncutaneous teratomatous elements and that an important criterion for its diagnosis is the absence of IGCNU. It also supports that it should be categorized separately from mature testicular teratoma because of the malignant nature of the latter in postpubertal patients. These observations suggest that there are at least two pathways for testicular teratomas in postpubertal patients: the more common being through IGCNU by differentiation from an invasive malignant germ cell tumor and the less common one, taken by dermoid cyst, by direct transformation from a nonmalignant germ cell.

The authors describe 10 sex cord-stromal tumors of the testis that incorporated germ cells, thereby mimicking the unclassified type of mixed germ cell sex cord-stromal tumor (MGCSCST). These neoplasms occurred in patients from 3 to 48 years old (mean age, 26 years) who presented with testicular masses. On microscopic examination, nine tumors had a combination of tubular and cord-like arrangements of sex cord cells with transition to spindle-shaped tumor cells. They were diagnosed as either unclassified sex cord-stromal tumors (n = 5) or Sertoli-stromal cell tumors (n = 4). One tumor was a pure Sertoli cell tumor. The admixed germ cells were usually at the periphery and in clusters, but occasionally were in the center or more diffuse. In nine patients the germ cells resembled spermatogonia, having round nuclei with uniform, dusty chromatin and inconspicuous or small nucleoli. None of these cells stained with a variety of markers used for neoplastic germ cells, and in one case in which the non-neoplastic Sertoli cells were strongly reactive for inhibin but the neoplastic Sertoli cells were not, all the germ cells within the tumor occurred adjacent to inhibin-positive Sertoli cells. With static cytophotometry, a diploid deoxyribonucleic acid content was found in these germ cells in the two investigated cases. In one case the germ cells had the morphologic appearance of seminoma cells and they stained positively for the markers of neoplastic germ cells. This case was interpreted as a "collision" tumor between a Sertoli cell tumor and a seminoma. The authors conclude that sex cord-stromal tumors with entrapped germ cells of the testis are more common than unclassified MGCSCSTs--a bona fide testicular example of which has not been seen by any of the authors.

A total of 91 men had histologically documented late recurrences of testicular germ cell tumors characterized by a complete response to treatment with a subsequent disease-free interval of at least 2 years and no evidence of a second primary lesion. Ninety percent of the patients for whom information was available received chemotherapy shortly after their initial diagnosis of testicular germ cell tumors; most of the other patients were known to have stage I disease initially. Overall, 60% of patients had teratoma in their late recurrences, including 20 patients (22%) in whom teratoma was the only element. Thus, teratoma was the most common type of neoplasm in late recurrences. Excluding teratoma coexisting with other types of neoplasms, yolk sac tumor was the most frequent type of tumor in patients with late recurrence. It occurred in 47% of patients, either alone or with teratoma, another nonteratomatous germ cell tumor type, or a "nongerm cell malignant tumor." Unusual types of yolk sac tumor, including glandular, parietal, clear cell, and pleomorphic patterns, were seen frequently in late recurrences and often raised differential diagnostic problems with "nongerm cell" carcinomas. A smaller number of late recurrences consisted of other types of neoplasms. Twenty percent of patients with late recurrence had a nonteratomatous germ cell tumor other than yolk sac tumor, either alone, with yolk sac tumor, or with a "nongerm cell malignant tumor." Most of these nonteratomatous germ cell tumors other than yolk sac tumor were embryonal carcinoma, although rarely seminoma and choriocarcinoma were encountered. "Nongerm cell malignant tumors," including both sarcomas and carcinomas of various types, occurred in 23% of late-recurrence patients, either alone or with a nonteratomatous germ cell tumor. Late recurrences were seen in many different sites in these patients, including the retroperitoneum, abdomen, pelvis, liver, mediastinum, lung, bone (femur, vertebra, and rib), lymph nodes outside the retroperitoneum and mediastinum (supraclavicular, neck, and axillary regions), scrotum and inguinal regions, adrenal gland, chest wall, and buttocks. Follow-up data were available for 79 of the 91 patients studied. Duration of follow-up ranged from 2 months to 13 years after the patient's first late recurrences; the mean length of follow-up was 4.8 years. Patients whose late recurrences consisted of teratoma only had the most favorable outcomes, with 79% having no evidence of disease at last follow-up. Patients whose late recurrences consisted of pure "nongerm cell malignant tumor" or pure germ cell tumor (yolk sac tumor or other types) had a much worse prognosis: Only 36% to 37% were alive with no evidence of disease. Patients with two different types of nonteratomatous malignancies in their late recurrences had a dismal clinical course: Only 17% with both yolk sac tumor and other nonteratomatous germ cell tumor had no evidence of disease, whereas no patient with both nonteratomatous germ cell tumor and "nongerm cell malignant tumor" was disease free. Late recurrences consisting of teratoma alone often have a favorable outcome, but the prognosis in all other patients is poor. Furthermore, late recurrence is not likely to respond to chemotherapy and is best treated by surgical excision when possible.

We report four cases of Leydig cell tumor of the testis with a microcystic pattern that mimicked yolk sac tumor. The patients ranged in age from 27 to 35 years and, except for one tumor that was discovered incidentally, presented with testicular masses. All tumors were intratesticular, and three were well circumscribed by a rim of fibrous tissue, whereas one showed minor, focal extension into the adjacent testis. The tumors typically had a vaguely lobular architecture subdivided by fibrous bands. Three of the cases had a complex microcystic appearance caused by individually vacuolated cells and coalescent cystic spaces; this pattern accounted for the majority of two tumors. Another case had focal collections of Leydig cells with prominent cytoplasmic vacuoles but lacked the coalescent spaces. The microcyst contents ranged from optically clear to eosinophilic or lightly basophilic, with the latter having the staining qualities of acid mucopolysaccharide. Three tumors had uniform, bland nuclei and low mitotic rates (<1 mitotic figure per 10 high power fields), but one had marked, random nuclear pleomorphism and an average mitotic rate of five mitotic figures per 10 high power fields. By immunohistochemistry, all were diffusely positive for vimentin; two of three were positive for inhibin, and one showed focal positivity for cytokeratin (CAM 5.2). All were negative for alpha-fetoprotein and placentalike alkaline phosphatase and, apart from having microcystic and solid areas, lacked other features typical of yolk sac tumor. Clinical follow-up ranged from 2 months to 2 years with no patient having recurrence or metastasis. The distinction of Leydig cell tumor from yolk sac tumor has important clinical implications because patients with the former usually receive only clinical follow-up, but the latter often requires chemotherapy.

Nephroblastoma-like tumors (NLTs) developed in metastatic sites in nine men with testicular germ cell tumors (GCTs). These tumors had a characteristic "triphasic" admixture of primitive tubular structures, sometimes with a glomeruloid pattern, blastema and stroma. Skeletal muscle differentiation was apparent in two cases. Specific neuroendocrine markers (synaptophysin and chromogranin A) were negative. All patients were treated by surgical excision. Six patients were alive with no evidence of disease from 4 to 12 years after diagnosis of GCT and NLT. One patient was alive with disease 6 years after diagnosis of GCT and 3 years after diagnosis of NLT. One man who also had metastatic primitive neuroectodermal tumor (PNET) had short survival, and one patient died of postoperative infection. We conclude that patients with testicular GCTs in whom NLTs develop in metastatic sites often experience prolonged survival. Surgical excision appears to be adequate treatment for NLT arising in metastatic testicular GCT in most patients. It is important to distinguish NLTs from PNETs in metastatic GCTs because of the more aggressive course and the frequently fatal outcome of the latter.

We report six malignant and six benign large cell calcifying Sertoli cell tumors of the testis and compare the features of malignant and benign cases based on these cases and those in the literature. All the tumors in this report consisted of sheets, nests, solid tubules, and cords of eosinophilic cells, with focal calcifications, as well as a substantial neutrophilic infiltrate in 11 of them. Analysis of our cases and those in the literature showed that the malignant tumors were unilateral and solitary and occurred at a mean age of 39 years (range 28-51 years), whereas the benign neoplasms were bilateral and multifocal in 28% of cases and occurred at a mean age of 17 years (range 2-38 years). Only one malignant tumor occurred in a patient with evidence of a genetic syndrome (Carney syndrome), whereas 36% of benign tumors had various genetic syndromes or endocrine abnormalities. Most of the tumors in the latter cases were bilateral and multifocal. There were strong associations of malignant behavior with size >4 cm, extratesticular growth, gross or microscopic necrosis, high-grade cytologic atypia, vascular space invasion, and mitotic rate greater than three mitoses per 10 high-power fields. All malignant cases exhibited at least two of these features, whereas all benign cases lacked any of them. The presence of any one of these features in a solitary large cell calcifying Sertoli cell tumor, especially in a patient >25 years of age, should be viewed as suspicious for malignant behavior, whereas the presence of two or more of these features indicates a strong probability of a malignant course. "Low" percentages (< or =35%) of tumor cells staining for proliferating cell nuclear antigen (PCNA) also may correlate with benign behavior, but some benign tumors have high PCNA values. Ki-67 values (MIB-1 antibody) did not correlate with biologic behavior, nor did immunostains for p53 protein.

Twenty-nine young men (mean age 29 years) had primitive neuroectodermal tumors (PNETs) arising in germ cell tumors (GCTs). Nine patients had PNETs confined to the testis, eight patients had PNETs in the testis and at metastatic sites, and 12 patients had PNETs identified only at extratesticular sites. Immunohistochemistry was of use in the further classification of these PNETs as neuroblastoma, medulloepithelioma, peripheral neuroepithelioma, or ependymoblastoma. The histologic pattern of PNETs in the testis (neuroblastoma or medulloepithelioma) did not predict which tumors metastasized. PNETs localized to the testis did not affect prognosis. Eight patients with no PNETs outside the testis were free of disease 1 month to 10 years after diagnosis. PNETs in extratesticular sites were an adverse prognostic factor. Nineteen patients with extratesticular PNETs had adequate clinical follow-up. Thirteen are dead of disease from 4 months to 5 1/2 years (mean 26 months) after diagnosis, four are alive with disease 6 months to 2 years after diagnosis, and two have no evidence of disease with short follow-up (6 and 17 months). Mean survival was longer (34 months) for patients whose extratesticular PNET was neuroblastoma than for those with other types of PNETs (13 months). Chemotherapy directed against GCTs was not effective in patients who developed metastatic PNETs of GCT origin. We conclude that extratesticular PNETs in patients with testicular GCTs are usually fatal, but patients with neuroblastomatous metastases may have a more prolonged course.

We report two unusual forms of testicular trophoblastic tumor. One was a mixed germ cell tumor in a 19-year-old man that had a predominant component of nodules of cytotrophoblast cells with only rare syncytiotrophoblast cells. These nodules of "monophasic" choriocarcinoma were diffusely positive for human chorionic gonadotropin (hCG), which stained the syncytiotrophoblast cells more intensely; stains for human placental lactogen (HPL) highlighted only the latter cells. The second tumor occurred in a 16-month-old boy. It consisted of a pure proliferation of intermediate trophoblast cells and was identical to the placental site trophoblastic tumor of the uterus. The tumor cells showed diffuse immunoreactivity for HPL and patchy staining for hCG. Despite the occurrence of vascular wall invasion, the patient was alive and well at 8 years follow-up with no treatment other than orchiectomy. These cases show that trophoblastic tumors other than classic choriocarcinoma occur rarely in the testis. The differential diagnosis of the "monophasic" choriocarcinoma included seminoma and the solid variant of yolk sac tumor, but the tumor had larger, more irregular nuclei than those of seminoma and was not associated with distinctive yolk sac tumor patterns. The placental site trophoblastic tumor may be confused with Leydig cell tumor or choriocarcinoma, but awareness of its occurrence in the testis and the immunohistochemical findings should permit its recognition.

Desmoplastic small round cell tumor (DSRCT) typically occurs in the abdomen but may also present at other sites. We report six cases of paratesticular DSRCT. The patients, who ranged in age from 17 to 37 (mean, 28) years, presented with a scrotal mass (five cases) or testicular pain (one case). Grossly, the tumors were white to tan and firm. Typically, they involved the paratesticular soft tissue, serosal surfaces and the epididymis near the junction with the rete testis. Microscopically, the tumors consisted of nests of mitotically active "small blue cells" with scant cytoplasm embedded in a densely fibrotic stroma. Two tumors showed focal tubule formation; one of these also formed rosettes. The tumors exhibited the typical immunophenotype of DSRCT (positivity for keratin, vimentin, desmin, and neuron-specific enolase but nonreactivity with HBA-71 and anti-S-100). Four tumors metastasized to lymph nodes (retroperitoneal, cervical, and two unspecified); pulmonary metastases occurred in one of these cases and in one patient without lymph node metastases. One of the above patients treated with chemotherapy, died of disease at 16 months. The patients with pulmonary metastases (one of whom also had lymph node metastases) were treated with aggressive chemotherapy and are alive and apparently disease-free at 2.5 and 3 years, respectively. Three of the six patients, two of whom had known metastases, were lost to follow-up. The DSRCT of the paratestis has histologic and immunohistochemical features identical to its abdominal counterpart and must be differentiated from other "small blue cell" tumors of the paratesticular region.

Testicular germ cell neoplasia, a disease predominantly of young men, is, for unknown reasons, increasing in incidence. Cryptorchidism, a prior testicular germ cell tumor, a family history of testicular germ cell tumors, and somatosexual ambiguity syndromes remain well-established risk factors. Intratubular germ cell neoplasia of the unclassified type represents the common precursor to the great majority of testicular germ cell tumors, and its identification in testicular biopsies reliably identifies those patients who will often progress to an invasive lesion. Seminoma appears to represent the invasive derivative of intra-tubular germ cell of neoplasia of the unclassified type; problematic variants include seminomas with tubular, granulomatous, and edematous patterns. Spermatocytic seminoma is an essentially nonmetastasizing neoplasm unless complicated by the rare development of a sarcomatous component. Embryonal carcinomas usually occur admixed with other germ cell tumor types. The combination of positivity for placental alkaline phosphatase and negativity for epithelial membrane antigen can assist in the distinction of embryonal carcinomas from somatic carcinomas. The treatment of clinical stage I patients with nonseminomatous germ cell tumor with "surveillance only" may be contraindicated depending on features that include the proportion of embryonal carcinoma and the presence of lymphovascular invasion in the orchiectomy specimen. It is important to be aware that pure, mature teratomas in postpubertal patients may be associated with metastases of teratomatous or nonteratomatous type Yolk sac tumor is characterized by numerous patterns including glandular, myxomatous, sarcomatoid, hepatoid, and parietal variants. Choriocarcinomas classically have a biphasic pattern of syncytiotrophoblast and cytotrophoblast; trophoblastic proliferations lacking a biphasic pattern also occur but are difficult to classify unless this category is broadened. Mixed germ cell tumors, consisting of two or more different elements, are quite common. The polyembryoma is a distinctive, well-organized form of mixed germ cell tumor consisting of embryonal carcinoma and yolk sac tumor.

We studied five cystic ovarian mucinous tumors with spindle cell mural nodules to define their histologic and immunohistochemical properties. Three of these mural nodules consisted of carcinomatous nests surrounded by highly pleomorphic polygonal and spindle cells. There were transition zones between the pleomorphic cells and the cell nests. In all three cases, both cell populations coexpressed cytokeratin and vimentin, suggesting a diagnosis of anaplastic carcinoma. A fourth nodule consisted of moderately differentiated adenocarcinoma embedded in prominent, cytologically uniform spindle cells. These cells were histologically distinct from the carcinoma; there were no zones of transition. The carcinoma was strongly positive for cytokeratin but only weakly positive for vimentin; the spindle cells expressed vimentin but not cytokeratin. We diagnosed this lesion as carcinoma with a reactive spindle cell stroma. A fifth mural nodule was composed entirely of interlacing fascicles of uniform spindle cells that were negative for cytokeratin but positive for vimentin, muscle-specific actin, and desmin; these findings support a diagnosis of leiomyoma. Two of the four patients with malignant nodules died of disease; the rest are alive and disease-free after follow-up intervals ranging from 1 to 4 years. This study demonstrates the usefulness of immunohistochemistry in distinguishing variant forms of spindle cell mural nodules in cystic ovarian mucinous tumors. It further suggests that malignant nodules do not necessarily carry a poor prognosis.

The presence of eosinophilic, hyaline globules in association with epithelial hyperplasia was noted in the rete testis of three patients with germ cell tumors. In the more florid examples, this proliferation formed a solid and microcystic pattern that, in association with the hyaline globules, mimicked a yolk sac tumor component. However, the bland cytologic features of the cells and the conformation to the configuration of the rete testis were keys to its reactive nature. A subsequent review of 48 testicular specimens containing well-defined areas of the rete testis showed hyaline globule formation in the rete testis or tubuli recti in 16 of 27 germ cell tumors, one of five other testicular tumors (four stromal tumors and one plasmacytoma), and none of 16 nonneoplastic cases. Many of the cases that had hyaline globules also showed epithelial hyperplasia. Further analysis demonstrated an incidence of rete testis invasion by neoplasm in cases that had hyaline globules, with or without epithelial hyperplasia, that was significantly higher (p less than 0.01) than that seen in neoplastic cases lacking hyaline globules. We concluded that this pseudoneoplastic reaction developed secondary to invasion of the rete testis by tumor. Immunostains supported the nonneoplastic nature of the proliferative lesions and indicated that the globules represented various proteins that had been absorbed from the lumen of the rete testis by the epithelial-lining cells but not successfully secreted.

Epithelioid sarcoma (ES) and malignant rhabdoid tumor (MRT) have heretofore been regarded as two separate clinicopathologic entities. However, they have some histologic similarities, and both represent histogenetic and phenotypic enigmas. This study reports the pathologic and immunohistochemical findings of four vulvar neoplasms occurring in young women that represented diagnostic dilemmas because of their similarity to both ES and MRT. Only one case had the classic histologic features of ES, whereas, in our opinion, the other three cases fulfilled the histologic criteria of MRT, despite the fact that two of the three cases were reported earlier as examples of ES. Neither electron microscopy nor immunohistochemistry has been found to be helpful in separating ES from MRT, mainly because they share several ultrastructural and immunophenotypic features. The behavior of these vulvar tumors--ours and the few published examples of ES--is generally aggressive, more in keeping with MRT than classic ES. We believe that some, if not most, putative ES of the vulva are in fact MRT, a neoplasm with an unfavorable prognosis.

We assessed 50 germ cell tumors with areas of yolk sac tumor (YST) for a variety of features including histologic patterns; hyaline droplets; syncytiotrophoblastic elements; hepatic, enteric, and parietal yolk sac differentiation; and granulomatous reaction. Of prime interest was the fact that many YSTs formed hepatic-like foci (22%), enteric-like glands (34%), and parietal yolk sac structures (92%). Hepatoid areas were characterized by nests and cords of polygonal, acidophilic cells with prominent nucleoli and intense cytoplasmic staining for alpha-fetoprotein. Enteric differentiation occurred as well-defined glands with a sharp, striated border and relatively bland nuclear features. Ultrastructurally these glands had apical microvilli with associated glycocalyx and long anchoring rootlets. The apical cytoplasm and luminal contents stained for carcinoembryonic antigen. Parietal yolk sac differentiation was characterized by the intercellular accumulation of basement membrane substance as generally thick and longitudinally arranged bands of eosinophilic material. Such material, by electron microscopy, was both intra- and extracellular, and had irregular outlines and inhomogeneous electron density. It contrasted with the strictly intracellular, round, homogeneous, hyaline globules that, we believe, represent visceral yolk sac differentiation. This intercellular material stained positively for laminin, a basement membrane component. Assessment of 22 embryonal carcinomas and 24 germinomas failed to show hepatic, enteric, and parietal yolk sac features, with one possible exception. We believe these features, especially parietal yolk sac differentiation, are helpful in differentiating YSTs from embryonal carcinomas and germinomas.

The clinical and pathologic features of 86 roentgenographically solitary pulmonary granulomas were reviewed to determine etiology and to provide guidelines for histologic evaluation. Fungal or acid-fast organisms were identified within the tissue in 60 cases (70%) and fragments of a helminth were found in one. The organisms were almost always present in the center of necrotic granulomas, and examination of two blocks containing active granulomas was usually sufficient for their identification. Microbiological cultures were less productive than direct examination of the tissue. In 25 cases an infectious etiology could not be identified: two were diagnosed as hyalinizing granuloma, one as Wegener's granulomatosis, and 22 were not further classified. A prominent overlapping spectrum of histologic features was found between infectious granulomas and Wegener's granulomatosis, suggesting that the latter may represent an abnormal immune response to an infectious agent that is no longer identifiable within the tissue. Caution is urged in diagnosing limited Wegener's granulomatosis and other pulmonary angiitides in patients with roentgenographically solitary granulomas.

Nine men with testicular germ cell tumors developed one of two types of histologically similar cystic lesions that had features of choriocarcinoma. In five cases, these choriocarcinoma-like lesions (CCLL) were felt to represent an unusual proliferation of teratomatous epithelium (teratomatous CCLL); whereas in four cases, the CCLL was felt to represent a nonbiphasic and cystic form of choriocarcinoma similar to the atypical choriocarcinoma described by Mazur et al. except for its cystic nature. Both types usually occurred as focal findings associated with teratomas. Eight of nine patients had received chemotherapy prior to excision of the CCLL. Teratomatous CCLLs often had a lacelike arrangement of atypical epithelium around cysts that contained homogeneous secretion. Mucicarmine stains were positive in four of five cases of teratomatous CCLLs. Cystic atypical choriocarcinoma consisted of stratified mononucleated cells lining cysts containing a coagulum of eosinophilic material. Stains for human chorionic gonadotropin (HCG) were positive in three of four cases of cystic atypical choriocarcinoma, although serum HCG elevations were either negative or just slightly elevated preoperatively. Five patients with a CCLL who were clinically free of disease following surgical excision and who received no additional chemotherapy remained well on follow-up (average, 1.9 years). We encourage the separate recognition of these lesions so that future studies may determine their clinical significance more precisely.