Congenital "neurovascular hamartoma" of the skin. A possible marker of malignant rhabdoid tumor

Cutaneous manifestations of congenital malignant rhabdoid tumor: Unusual papillomatous plaques and other skin presentations

BACKGROUND/OBJECTIVES

Malignant rhabdoid tumors (MRT) are highly aggressive tumors with a predilection for the kidney, central nervous system, and soft tissues that usually affect young children under three years of age. Primary presentation in the skin is rarely reported, and features of the cutaneous manifestations are not well described. We report six cases of metastatic MRT that first manifested with congenital nodules and masses in the skin.

METHODS

Retrospective case series.

RESULTS

The cutaneous presentation of MRT may be heterogeneous and can present with solitary or multifocal skin lesions. Congenital polypoidal and papillomatous plaques, including those with histologic features of neurovascular hamartoma, appear to be a unique presentation of MRT in the infant.

CONCLUSIONS

Malignant rhabdoid tumor should be considered in the differential diagnosis of unusual skin tumors in neonates and infants.

Embryonal Tumors of the Central Nervous System: An Update

Embryonal tumors of the central nervous system (CNS) are rare, high-grade neoplasms predominantly affecting the pediatric population. Well-defined embryonal tumors include medulloblastoma, atypical teratoid/rhabdoid tumor, embryonal tumor with multilayered rosettes, C19MC-altered and embryonal tumor with multilayered rosettes, not otherwise specified, pineoblastoma, pituitary blastoma, CNS neuroblastoma, and ganglioneuroblastoma. Although their prognosis is nearly uniformly poor, the rapidly evolving understanding of their molecular biology contributes to diagnosis, prognosis, treatment, and clinical trial participation. Knowledge of current tumor stratification and diagnostic techniques will help pathologists guide care and preserve tissue for necessary or desired additional testing.

SMARCB1-deficient Tumors of Childhood: A Practical Guide

The SMARCB1 gene ( INI1, BAF47) is a member of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex, involved in the epigenetic regulation of gene transcription. SMARCB1 acts as a tumor suppressor gene, and loss of function of both alleles gives rise to SMARCB1-deficient tumors. The prototypical SMARCB1-deficient tumor is the malignant rhabdoid tumor (MRT) which was first described in the kidney but also occurs in soft tissue, viscera, and the brain (where it is referred to as atypical teratoid rhabdoid tumor or AT/RT). These are overwhelmingly tumors of the very young, and most follow an aggressive and ultimately lethal course. Morphologically, most but not all contain a population of "rhabdoid" cells, which are large cells with abundant cytoplasm, perinuclear spherical inclusions, and eccentric vesicular nuclei with large inclusion-like nucleoli. MRT immunohistochemistry reveals complete loss of SMARCB1 nuclear expression, and molecular analysis confirms biallelic SMARCB1 inactivation in the vast majority. Rare AT/RTs have loss of SMARCA4, another SWI/SNF member, rather than SMARCB1. With the widespread adoption of SMARCB1 immunohistochemistry, an increasing number of SMARCB1-deficient tumors outside of the MRT-AT/RT spectrum have been described. In addition to MRT and AT/RT, pediatric tumors with complete loss of SMARCB1 expression include cribriform neuroepithelial tumor, renal medullary carcinoma, and epithelioid sarcoma. Tumors with variable loss of SMARCB1 expression include subsets of epithelioid malignant peripheral nerve sheath tumor, schwannomas arising in schwannomatosis, subsets of chordomas, myoepithelial carcinomas, and sinonasal carcinomas. Variable and reduced expression of SMARCB1 is characteristic of synovial sarcoma. In this review, the historical background, clinical characteristics, morphology, immunohistochemical features, and molecular genetics most germane to these tumors are summarized. In addition, familial occurrence of these tumors (the rhabdoid tumor predisposition syndrome) is discussed. It is hoped that this review may provide practical guidance to pathologists encountering tumors that have altered expression of SMARCB1.

Surgery and actinomycin improve survival in malignant rhabdoid tumor

Purpose. Malignant rhabdoid tumor (MRT) is an uncommon tumor that rarely occurs outside of renal and central nervous system (CNS) sites. Data from the literature were compiled to determine prognostic factors, including both demographic and treatment variables of malignant rhabdoid tumor, focusing on those tumors arising in extra-renal, extra-CNS (ER/EC MRT) sites. Patients and Methods. A systematic review and meta-analysis was performed by extracting demographic, treatment, and survival follow up on 167 cases of primary ER/EC MRT identified in the literature. Results. No survival differences were observed between those treated with or without radiation, or with or without chemotherapy. A Cox regression of overall survival revealed several independent prognostic factors. Surgical excision had a 74% (P = 0.0003) improvement in survival. Actinomycin had a 73% (P = 0.093) improvement in survival. Older age was associated with improved survival. The four-year survival, by Kaplan-Meier estimates, comparing patients less than two years old versus older than two at diagnosis was 11% versus 35%, respectively (P = 0.0001, Log-Rank). Conclusion. ER/EC MRT is a rare, soft-tissue tumor with a poor prognosis most commonly occurring in children. Surgical resection, treatment with actinomycin, and older age at diagnosis are all associated with improved survival.

Fetal and neonatal rhabdoid tumor

PURPOSE

Few studies have focused on the behavior of rhabdoid tumor (RT) in the fetus and neonate. The purpose of this review is to show that perinatal RTs are associated with unusual findings and a poor prognosis.

METHODS

The author conducted a 40-year systematic review of the literature. Clinical presentation, pathology, management, and outcome of 72 fetuses and neonates with RTs are discussed.

RESULTS

Seventy-two fetuses and neonates presented with RTs detected prenatally (n = 12) and during the neonatal period (n = 60). The review consisted of 3 main groups: extrarenal noncentral nervous system (CNS) RT, renal RT, and CNS RT. There were some group differences in survival: extrarenal non-CNS RT (3/33 or 9.1%), renal RT (2/27 or 7.4%), and CNS RT (2/12 or 16.7%). Metastatic RT was present at diagnosis in more than half the patients (41/72 or 57%) who had a survival of 2.3%. The overall survival was 9.7%. For statistical results, there was no significant difference in survival among the 3 groups by type of tumor (P = .692). chi(2) analysis for survival with and without metastases was not valid due to small sample size.

CONCLUSIONS

The review shows that extrarenal RT was more common than either renal RT or CNS RT groups that is different than that observed in older individuals. Concomitant brain tumors were found in almost a third of fetuses and neonates. The CNS involvement occurred more often in patients with renal RT than in those with extrarenal RT. Metastatic disease at diagnosis was noted in more than half of the patients. Higher stage and presence of a CNS tumor were significant determinants in survival.

Mesothelioma with rhabdoid features: an ultrastructural and immunohistochemical study of 10 cases

Mesotheliomas with rhabdoid morphology are rare and only two individual case reports have been documented in the literature. This author reports a series of 10 cases of mesotheliomas with rhabdoid features, nine of which originated in the pleura and one in the peritoneum. Eight of the patients were men and two were women. Six patients had a history of asbestos exposure. Histologically, seven of the mesotheliomas were epithelioid, two sarcomatoid, and one biphasic. The proportion of the rhabdoid cells seen in these cases constituted 15-75% of the individual tumors. Cytoplasmic staining in the rhabdoid cells was seen for pan-keratin and vimentin in all 10 cases, for keratin 7 in eight of eight, for calretinin in nine of 10, and for keratin 5/6 in seven of nine. Nuclear positivity for WT1 was observed in the rhabdoid cells of four of seven cases and membranous reactivity for mesothelin in four of six, and for podoplanin in two of six. Only one case showed desmin positivity in sparse cells in the nonrhabdoid component of the tumor. All of the cases were negative for CEA, MOC-31, TAG-72, CD15, CD34, bcl2, muscle-specific actin, and TTF-1. Ultrastructural studies revealed paranuclear collections of intermediate filaments, but no evidence of rhabdomyoblastic differentiation was seen. The mean survival of five of the six patients for whom this information was available was 3.8 months. The remaining patient had a survival time of 1 year. It is important for pathologists to be aware that mesotheliomas can present rhabdoid features, not only because they can be confused with other malignancies that can exhibit a similar morphology, but also because of their apparently unusually aggressive behavior. The value of immunohistochemistry and electron microscopy in the differential diagnosis of these tumors is discussed.

Intraventricular rhabdoid tumor

Malignant rhabdoid tumor (MRT) most commonly occurs in kidney. In the central nervous system, cerebellum is the most common site of occurrence. CNS rhabdoid tumors typically occur in small children, do not respond favorably to treatment and are usually fatal within 1-year. Here is reported a 4-year-old child who presented with features of raised intracranial pressure. Apart from papillodema, there were no neurological signs. Imaging revealed a left lateral ventricular heterogeneous mass abutting the foramen of monro, with mild irregular contrast enhancement and hydrocephalus. The child underwent right ventriculo-peritoneal shunt followed by craniotomy and gross total tumor resection. He was discharged 10-days after surgery without any neurological deficits. Histopathology revealed features compatible with rhabdoid tumor. Despite radiotherapy and chemotherapy, the child died of progressive disease 10-months after surgery. The highly malignant nature of this tumor makes early diagnosis essential for aggressive management and prognostication.

Renal cell carcinoma with rhabdoid features

Neoplasms with rhabdoid features have been reported at many anatomic sites. In the kidney, rhabdoid tumors are typically found in children, whereas only rare examples have been reported in adults. Little is known of renal cell carcinomas (RCCs) that exhibit rhabdoid features. The objective of this study was to determine the incidence of RCC with rhabdoid attributes and characterize the histologic, immunophenotypic, and ultrastructural features by retrospective analysis of 480 consecutively identified cases of RCC in radical nephrectomy specimens. Immunohistochemical evaluation was performed in cases with rhabdoid foci using a panel of antibodies to pancytokeratin (pan-CK), CK7, CK20, epithelial membrane antigen (EMA), S-100 protein, desmin, vimentin, neuron-specific enolase (NSE), muscle-specific actin (MSA), smooth muscle actin (SMA), human melanoma, black-45 (HMB-45), and glial fibrillary acidic protein (GFAP). Electron microscopy was also performed in selected cases. The presence and extent of rhabdoid foci in relation to pathologic stage and grade were assessed. Twenty-three of 480 cases of RCC (4.7%) exhibited rhabdoid features. The 23 patients were all adults with a mean age of 61.8 years (age range, 33-84 yrs). Fifteen of the patients were men and eight were women. Histologically, the rhabdoid foci were typified by sheets and clusters of variably cohesive, large epithelioid cells with vesicular and often eccentric nuclei, prominent nucleoli, and large, paranuclear intracytoplasmic hyaline globules (inclusions). The presence of these rhabdoid features was related to high histologic Fuhrman grade of the nonrhabdoid carcinoma component, with an incidence of 0 of 84 grade I cases, eight of 300 grade 2 cases (2.6%), six of 70 grade 3 cases (8.9%), and nine of 26 grade 4 cases (34.6%; p = 3 x 10(-9)). The rhabdoid foci were all high grade. The presence of rhabdoid foci was also found in higher stage carcinomas. A total of 52% (12 of 23) of RCC cases with rhabdoid features exhibited extrarenal extension compared with 28% (24 of 92) of contemporary RCCs without rhabdoid features (p = 0.03). The size of the rhabdoid component ranged from 1 mm to more than 2 cm and comprised 1% to 50% of the renal mass. Immunoreactivity for vimentin (100%), NSE (79%), and panCK (56%) was present in the majority of cases. Substantial percentages of cases were immunopositive for EMA (47%) and S-100 protein (37%), with minimal to no immunohistochemical reactivity for CK7 (5%), SMA (5%), CK20 (0%), desmin (0%), MSA (0%), HMB-45 (0%), and GFAP (O%). A distinctive globular, paranuclear reaction pattern was found for the cytokeratin, EMA, and vimentin immunostains. Ultrastructurally, the rhabdoid cells had paranuclear intermediate filament aggregates or paranuclear condensation of organelles, often associated with peripheral vacuolization. Adult RCCs may harbor a rhabdoid component, and these neoplasms can be regarded as "composite" tumors. Rhabdoid elements are important to identify because of their high-grade nature, and association with high stage. Adult RCC with rhabdoid elements should be distinguished from pure rhabdoid tumors of kidney, in light of their clinicopathologic differences. Rhabdoid differentiation in adult renal cell carcinoma may represent clonal divergence and/ or evolution, and emergence of a particularly aggressive element.

Inv(11)(p13p15) and myf-3(MyoD1) in a malignant extrarenal rhabdoid tumor of a premature newborn

We present a premature newborn of 32 wk of gestation with a congenital malignant extrarenal rhabdoid tumor (MERT) on the right shoulder with generalized metastases. Standard histologic, immunohistochemical, molecular and cytogenetic methods were used in the evaluation of diagnostic material. Biopsy of a skin lesion showed the histologic features of a malignant rhabdoid tumor. Cytogenetic analysis of the tumor cells revealed an inv(11)(p13p15) and additionally, an increased expression of myf-3 (myogenic determination factor, MyoD1) and PAX3 was detected. These results suggest an origin of the neoplasm derived from a pluripotent cell with the potential of myogenic differentiation. Tumor suppressor genes located on chromosome 11p13 and 11p15 may play an important role for malignant rhabdoid tumor development and progression.

Epithelial sheath neuroma: a new entity

The authors describe four examples of a peculiar cutaneous lesion characterized histopathologically by a proliferation of enlarged nerve fibers ensheathed by squamous epithelium involving the superficial dermis. The perineural epithelial sheaths were composed of uniform squamous epithelium with evidence of cornification in the form of dyskeratotic cells or resulting in orthokeratotic basket-weave corneocytes. Immunohistochemical studies confirmed the epithelial and neural nature of the two components of the lesions, with the nerve fibers expressing immunoreactivity for S-100 protein, neurofilaments, CD57, and nerve growth factor receptor, whereas the perineural epithelial sheaths showed immunoreactivity for cytokeratins. The authors propose the term "epithelial sheath neuroma" for this lesion and believe that it is a distinct and a previously undescribed benign neoplasm of both cutaneous nerves and epithelial elements.

Malignant rhabdoid tumor beside benign skin mesenchymal neoplasm with myofibromatous features

Only a few reports of primary cutaneous rhabdoid tumors have been published. We describe the case of a 3-month-old female patient who developed a rhabdoid type cutaneous sarcomatoid neoplasm in her upper back, close to a benign myofibromatous proliferation of infancy. The lesion was studied both by light microscopy and immunohistochemically. Flow cytometry was performed showing a DNA diploid profile of the malignant tumor. The pathological findings suggest a mesenchymal origin (hemangiopericytic or myofibroblastic type) for both tumors. The patient was surgically treated, but she died nine months later.

Congenital disseminated malignant rhabdoid tumor: a distinct clinicopathologic entity demonstrating abnormalities of chromosome 22q11

The clinical, pathologic, and immunohistochemical features of a widely disseminated tumor with rhabdoid phenotype are described in nine infants < or = 3 months of age. Five neonates had tumor evident at birth, two of which had placental metastases. The average survival following diagnosis was < 6 weeks. None of the infants had an apparent primary tumor in either the kidney or brain. In four cases, the dominant mass involved the head and neck region, and in two cases, the primary mass was paraspinal. The histologic features were those of a high-grade, round cell neoplasm with abundant cytoplasm and containing cells with cytoplasmic filamentous inclusions. Immunohistochemical studies revealed polyphenotypic antigen expression. Genetic information was available from eight of nine cases. Karyotype analysis revealed abnormalities of chromosome band 22q11-12 in three of six tumors. Fluorescence in situ hybridization studies or molecular studies demonstrated 22q11.2 deletions in all five cases with available frozen tissue, two of which had translocations involving 22q by karyotype analysis. The similar clinical and pathologic findings in these rapidly fatal tumors in infants and the demonstration of abnormalities of chromosome 22q11 in a majority of the cases supports their histogenetic and nosologic relationship to the family of malignant rhabdoid tumors that typically occur in young children in several anatomic sites, including kidney, soft tissues, liver, and brain. Like neuroblastoma and rhabdomyosarcoma, malignant rhabdoid tumor can appear as disseminated disease at birth or shortly thereafter.

"Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series

Eighteen examples of an unusual malignant soft-tissue neoplasm, the morphology of which ranged from that of "atypical" epithelioid sarcoma to that of a rhabdoid tumor or undifferentiated carcinoma (with transitional forms) are described. Patients included 11 males and seven females; their median age was 35.5 years with most patients aged 20 to 40 years. Development of a mass was the main presenting symptom. Six tumors developed in the pelvis and perineal region, four in the pubic region and vulva, three in the buttocks, one in the deep soft tissues of the left hip, one on the penis, one in left forearm, one in left axilla, and one on the occiput. Tumor size ranged from 1 to 20 cm (median, 4 cm). On microscopic examination, the tumor cells invaded the subcutaneous or deep soft tissues, had prominent epithelioid or rhabdoid features, had marked cytologic atypia, and grew in a multinodular pattern in half of the cases. Areas of necrosis were often seen. A granuloma-like pattern reminiscent of that observed in classic epithelioid sarcoma was observed in only two cases. Immunohistochemically, positivity for cytokeratin, epithelial membrane antigen, and vimentin was seen in all but one of the cases. Of 16 cases, 10 and eight tumors reacted with desmin and CD34, respectively; five of 15 reacted at least focally with smooth-muscle actin, whereas three of 13 and one of 10 reacted for HMB-45 and carcinoembryonic antigen, respectively. S-100 protein and CD31 yielded negative results. Seven tumors were investigated at the ultrastructural level, four of which showed prominent intracytoplasmic intermediate filament aggregates, often accumulating into paranuclear whorls, which is in keeping with the rhabdoid phenotype. Five tumors showed features of epithelial differentiation (i.e., tonofilament-like structures or desmosomes or both), whereas one tumor displayed features of myofibroblastic differentiation. Differential diagnoses include mainly conventional epithelioid sarcoma, extrarenal malignant rhabdoid tumor, epithelioid malignant peripheral nerve sheath tumor, melanoma, rhabdomyosarcoma, and undifferentiated carcinoma. Follow-up information on 14 patients (range, 4 months to 8 years; median, 19 months) revealed local recurrence in one case and metastatic dissemination in six patients, leading to death in five. In our opinion, the above-described neoplasms represent a usually "proximal-type" of epithelioid sarcoma. In contrast to the conventional, "distal-type" epithelioid sarcoma, the proximal variant is characterized by a predominantly large-cell, epithelioid cytomorphology, marked cytologic atypia, frequent occurrence of rhabdoid features, and lack of a granuloma-like pattern in most cases. It appears to be somewhat more aggressive (or at least metastasizes earlier) than usual epithelioid sarcoma.

Extrarenal rhabdoid tumour presenting as a congenital subcutaneous mass

Extrarenal malignant rhabdoid tumour is a rare neoplasm of childhood. A congenital example has only been reported once previously, presenting as a facial mass. We report a second congenital case with the tumour over the right shoulder in which postoperative investigations revealed multiple hepatic metastases proving fatal at 51 days, with adjuvent therapy felt inappropriate.