Ala B. Hamoudi

Spindle cell variants of embryonal rhabdomyosarcoma in the paratesticular region. A report of the intergroup rhabdomyosarcoma study

We reviewed 173 cases of paratesticular rhabdomyosarcoma (RMS) of Intergroup Rhabdomyosarcoma Studies (IRS)-I, -II, and -III for evaluation of possible histological factors that might account for the good prognosis of these patients. Almost all cases (161 of 173 cases, 93.1%) occurring in this site were of embryonal histology. A spindle- cell subtype of embryonal RMS was identified that presented a storiform growth pattern with abundant collagen between the tumor cells in most cases. Other tumors of this subtype showed an arrangement of tumor cells in bundles with a low to moderate amount of collagen, resembling a leiomyosarcoma. The other embryonal RMS in this site had the classical embryonal cytology. The spindle-cell subtype was highly differentiated by immunohistochemistry and electron microscopy. Lymph node metastasis was found in seven of 43 patients (16.3%) with a RMS of spindle-cell subtype, compared with 40 of 112 patients (35.7%) with RMS of non-spindle-cell type. Clinical data from patients with spindle-cell subtypes of the paratesticular lesions revealed that they almost always had an association with clinical groups of limited disease (32 patients, 74.4%, with Group I; 10 patients, 23.3%, with Group II disease) and a significantly better prognosis (95.5% survival at 5 years) when compared with patients with the classic embryonal variant of RMS (80% survival at 5 years, p<0.035). The incidence and anatomic distribution of this spindle cell subtype of embryonal RMS was estimated on 800 randomly selected patients from IRS-II. It was found in the head and neck, extremities, orbit, and some other sites, but 30.6% were located in the paratesticular area. Patients with spindle cell RMS of nonparatesticular sites usually had more extensive disease compared with patients having paratesticular lesions; two thirds of the cases had gross residual tumor after surgery or metastatic tumor at diagnosis. We conclude that spindle-cell RMS is a subtype of embryonal RMS with a very favorable prognosis. The site factor of the paratesticular localization may allow earlier diagnosis of the spindle-cell lesions compared with other sites. Other unknown factors may also play a role

Successful Treatment of Disseminated Central Nervous System Malignant Rhabdoid Tumor

Purpose Malignant rhabdoid tumor (MRT) of the central nervous system (CNS) is pathologically identical to MRT of the kidney. CNS MRTs have the clinicopathological behavior of a high-grade intracranial sarcoma, and the children have a very poor prognosis. We report on three cases of primary CNS MRT with a review and summary of the pediatric literature with respect to demographic features and multidisciplinary management. Patients and Methods The 18 cases reviewed had a male to female ratio of 1.0 and an extremely young median age of 32 months. Our three cases of CNS MRT were treated with surgery, chemotherapy, radiotherapy, and triple intrathecal (TIT) chemotherapy similar to the Intergroup Rhabdomyosarcoma Study III guidelines for parameningeal primary tumors with intracranial extension. Results The three patients described in this report are surviving with no evidence of disease at 5 years, 2 years, and 9 months from diagnosis. Before these three cases, only four of 16 reported patients were known to have survived. One unique case in our report involved disease in the cerebral cortex, sinuses, and orbit with metastases to the subarachnoid space. This metastatic MRT responded to treatment with TIT, multiagent chemotherapy and cranial-spinal radiation after partial resection of only the cortical portion of the MRT. Conclusions Disseminated CNS MRTs can be treated using multidisciplinary management with an approach similar to that used to treat rhabdomyosarcoma.

Childhood rhabdomyosarcoma with anaplastic (pleomorphic) features. A report of the Intergroup Rhabdomyosarcoma Study.

The plemorphic subtype of rhabdomyosarcoma (RMS) is now rearely diagnosed in both children and adults. Most cases previously called pleomorphic RMS are probably diagnosed as something else, most often embryonal RMS in children and malignant fibrous histicytoma in adults. To analyze the concept of plemorphic RMS in children, we reviewed the tumors of patients enterd on the Intergroup Rhabdomyosarcoma Study (IRS I, II, and III). The presence of cells with lobated, hyperchromatic nuclei at least three times larger than the common tumor cell population (anaplastic cells) was selected as the main criterion. Of about 3,000 cases, 110 showed these types of cells, had sufficient histologic material, and had available follow-up data. These tumors were divided into two subgroups: Subgroup I tumors contained only scattered anaplastic cells, and tumors with foci or large sheets of anaplastic cells were classified as subgroup II. Besides the anaplastic-pelmorphic areas, most of these tumors had distinctive features of embryonal RMS (105 cases) and rarely had-characteristies of alvelar RMS (five cases). The age distribution of these patients did not differ significantly from those whose tumors did not show the anaplastic features. the average being 6 years and the median 4 years. Lower extermity, retroperitoneum, and the head and neck region were the most common primary tumor sites. The 5-year surival rate was 60% for subgroup I tumors and 45% for subgrup II tumors compared with the survial rate of 68% for 482 IRS II embryonal RMS cases with no anaplastic-pleomorphic features. The lower survival rate for patients in subgroup II was statistically significnt (p = 0.004) and similar to the unfavorable survival of patients with alveolar RMS and undifferntiated sarcoma. Because anaplastic cells are seen in many soft tissue sarcomas and in both embryonal and alveolar RMS in children, this feature is not sufficiently untisual to separate a pleomorphic subtype of RMS. The presence of anaplastic cells in aggregates of diffuse sheets throughout the tumor, however, portends a poor survival for these patints.

Multiple neoplasms in an adolescent child associated with IGA deficiency.

A report is presented of an unusual occurrence of multiple primary malignant neoplasms in a young girl. Beginning at the age of 10 she had multiple adenomatous polyps removed from the colon over a 2‐year period. One of the polyps had a malignant transformation. During the ensuing 8 years, she developed malignant thymoma, squamous cell carcinoma of the scalp, adenocarcinoma of the colon, which recurred, and choroid tumor of the eye. She died at the age of 20 with malignant astrocytoma of the cerebrum. A brother died at the age of 16 because of lymphoma, lymphocytic, well differentiated, with invasion of the spinal column and meninges. The girl had a serum IgA less than 20% of normal level and her brother had total absence of IgA.

Undifferentiated sarcomas of children: pathology and clinical behavior--an Intergroup Rhabdomyosarcoma study.

Undifferentiated soft tissue sarcoma (UND-STS) is the most poorly defined tumor eligible for intergroup Rhabdomyosarcoma Studies (IRS). Recent IRS UND-STS experience was reviewed to assess the histologic characteristics and clinical behavior of undifferentiated sarcomas. Of the 1,527 patients entered on IRS-III and IRS pilot-IV, 96 had tumors classified by the IRS Pathology Committee as UND-STS. Of these, 52 had adequate histologic material for this study. After application of immunohistochemistry, 18 tumors were reclassified, mostly as embryonal rhabdomyosarcomas (RMS), primitive neuroectodermal tumors, and intraabdominal desmoplastic small found cell tumors. The remaining 34 UND-STS had a diffuse hypercellular histologic pattern made up of sheets of medium-sized cells. The tumor cells had a minimal to moderate amount of cytoplasm and a variable nuclear morphology, predominately vesicular with finely granular chromatin. Except for reactivity with antibodies against vimentin, most tumors had a negative immunohistochemical profile. The 5 year Kaplan-Meier survival estimate for patients with non-metastatic disease was 72%, a significant improvement when contrasted with patients diagnosed to have UND-STS in IRS-I and IRS-II.

Epithelioid Sarcoma in Childhood: An Immunohistochemical, Electron Microscopic, and Clinicopathologic Study of 11 Cases Under 15 Years of Age and Review of the Literature

Epithelioid sarcoma in a rare tumor and most of the cases occur in young adults. It is rare in childhood. We have been able to obtain data and histologic material for 11 patients with this disease. The primary sites were head and neck in three patients, inguinal region in one, and extremities in seven. The age range of the patients was 12 weeks to 13 years. There was a preponderance of males over females with a ratio of 1.75. The tumors presented with a typical nodular necrotizing pattern. In three cases giant osteoclast-like cells were present. The immunohistochemistry and electron microscopy showed features consistent with previous observations on epithelioid sarcomas. In one case islands of small dark cells noted on light microscopy were surrounded by basal lamina on electron microscopy. The cells inside the nests were undifferentiated. Six tumors studied by flow cytometry were in DNA diploid range. On follow-up, five children are alive and well 2 to 7 years after treatment. Three children died of tumor progression with metastases to lymph nodes and lungs. One child had been diagnosed only recently, and in one the disease has run a protractive course with multiple recurrences. The behavior of these epithelioid sarcomas in children is similar to that seen in adults, the prognosis being dependent on radical tumor surgery preventing recurrent disease. Long-term follow-up is necessary because the tumor may recur many years after the primary tumor was removed.

Undifferentiated sarcomas of children: Pathology and clinical behavior—an Intergroup Rhabdomyosarcoma Study

Undifferentiated soft tissue sarcoma (UND-STS) is the most poorly defined tumor eligible for intergroup Rhabdomyosarcoma Studies (IRS). Recent IRS UND-STS experience was reviewed to assess the histologic characteristics and clinical behavior of undifferentiated sarcomas. Of the 1,527 patients entered on IRS-III and IRS pilot-IV, 96 had tumors classified by the IRS Pathology Committee as UND-STS. Of these, 52 had adequate histologic material for this study. After application of immunohistochemistry, 18 tumors were reclassified, mostly as embryonal rhabdomyosarcomas (RMS), primitive neuroectodermal tumors, and intraabdominal desmoplastic small found cell tumors. The remaining 34 UND-STS had a diffuse hypercellular histologic pattern made up of sheets of medium-sized cells. The tumor cells had a minimal to moderate amount of cytoplasm and a variable nuclear morphology, predominately vesicular with finely granular chromatin. Except for reactivity with antibodies against vimentin, most tumors had a negative immunohistochemical profile. The 5 year Kaplan-Meier survival estimate for patients with non-metastatic disease was 72%, a significant improvement when contrasted with patients diagnosed to have UND-STS in IRS-I and IRS-II.