Rhabdomyosarcoma mimicking acute leukemia in an adult: report of a case with histologic, flow cytometric, cytogenetic, immunohistochemical, and ultrastructural studies

OBJECTIVES: To measure ground reaction force variables during lameness resulting from impaired tibial nerve function and to determine whether these variables changed significantly as recovery progressed. ANIMALS: 11 healthy Greyhounds of either sex, weighing between 22 and 39 kg. PROCEDURE: On 3 consecutive days before surgery, ground reaction forces were measured by force platform gait analysis at the trot. In dogs under general anesthesia, the left tibial nerve was crushed proximal to innervation of the gastrocnemius muscle. Gait analyses were repeated on days 8 to 10, 28 to 30, 43 to 45, 58 to 60, and 90 to 92 after surgery. Ground reaction force variables and stance time were compared among the 3-day clusters. RESULTS: 10 days after surgery, all dogs had weight-bearing lameness attributed to paralysis of muscles in the caudal compartment of the crus. Nerve regeneration resulted in functional recovery within 3 months. Decreases in vertical force were significant 10 days after surgery; thereafter, changes reflected gradual return of load bearing, with the most marked improvement between 10 and 45 days. At 90 days, vertical force variables were within 3% of presurgical values. Stance time for the left hind limb was significantly longer at 10, 30, and 45 days after surgery and was seen in all dogs, but returned to within 1 % of preoperative stance time at 90 days. The effect of tibial nerve dysfunction on braking or propulsive force was not significant. CONCLUSIONS AND CLINICAL RELEVANCE: The significant changes in vertical ground reaction forces in hind limbs of dogs during lameness that resulted from impaired tibial nerve function are detectable, as is response during recovery, by use of force platform analysis.     

Inflammatory pseudotumor of the urinary bladder. A clinicopathological, immunohistochemical, ultrastructural, and flow cytometric study of 13 cases

We report 13 cases of inflammatory pseudotumor of the urinary bladder in patients having no history of recent local trauma. The average age of the patients (eight females, five males) was 35.4 years (range, 19 to 60 years). Gross hematuria (nine of 13 cases) and recurrent cystitis (three of 13 cases) were the most common presentations. Cystoscopy and gross examination revealed either a polypoid intraluminal mass or a submucosal mural mass, ranging in size from 2 to 7 cm. The lesions were commonly gelatinous. Histological examination showed that the lesions consisted of spindle cells with tapering eosinophilic cytoplasm, typically widely separated in a vascular myxoid matrix with acute and chronic inflammatory cells. In four cases the lesions had more compact cellularity with areas of fibrosis and less myxoid change. The muscularis propria was involved in 10 cases, the perivesical fat in two cases. The spindle cells were immunoreactive for vimentin (10 of 10) and muscle-specific actin (10 of 10). A few cases exhibited immunoreactivity for smooth-muscle-specific actin (three of eight), cytokeratin (two of 10), desmin (two of nine), and epithelial membrane antigen (two of eight). Ultrastructural examination of four cases revealed myofibroblasts, fibroblasts, or a mixture of the two cell types. DNA content analysis by flow cytometry yielded diploid histograms (six of six). Clinical follow-up in all cases demonstrated no evidence of recurrence (mean follow-up, 25.8 months). The findings indicate that this lesion is a benign, likely inflammatory or reparative, mesenchymal lesion that can be recognized by its distinctive pathological features.     

Perineurioma with ossification: a case report with immunohistochemical and ultrastructural studies

We evaluated the elbow flexion test in 216 elbows without compression of the ulnar nerve at the cubital tunnel and without other neuropathies. We used Rayan's four positions as our test. The percentage of positive tests was only 3.6% at one minute, whereas evaluating the responses at three minutes we saw positive results in 16.2%. Therefore we find that if the test is performed for one minute it may be useful to help in diagnosing ulnar nerve compression at the cubital tunnel.     

Disseminated malignant histiocytosis in a golden retriever: clinicopathologic, ultrastructural, and immunohistochemical findings

Diagnosis of malignant histiocytosis (MH), a disorder characterized by systemic proliferation of morphologically atypical histiocytes and their precursors, in an 8-year-old neutered female Golden Retriever was based on light and electron microscopic and immunohistochemical findings. Clinically, the dog presented with unilateral forelimb lameness. Eight days after surgical exploration of a swollen brachium, the dog developed sudden onset of posterior paresis, fecal and urinary incontinence, and a flaccid tail. Necropsy revealed infiltrative and nodular lesions in the right forelimb and regional lymph nodes, thoracic and abdominal cavities, and lumbar epidural space. Gross lesions were not found in the lungs or integument. Histopathologic examination showed infiltrates of atypical histiocytes in skeletal muscle, joint, and regional lymph nodes of the right forelimb; intercostal muscle; lung; liver; spleen; pancreas; kidneys; and spinal dura. Most tumor infiltrates were nodular and composed of loosely aggregated cells that were 10-30 microns in diameter with abundant eosinophilic to foamy cytoplasm, had central or eccentric nuclei, and were periodic acid-Schiff negative. Many binucleated cells, multinucleated giant cells, and mitotic figures were seen. Tumor cells contained phagocytosed erythrocytes, mononuclear cells, and some leukocytes. Ultrastructural features of tumor cells included cytoplasmic lipid droplets, lysosomes, and phagolysosomes. Immunohistochemical studies on paraffin-embedded sections showed positive reactivity to human T-cell Ag (clone UCHL-1) and for lysozyme, alpha-1-antitrypsin, and cathespin B. Polyclonal intracellular immunoglobulin reactivity and lectin binding (peanut, soybean, and wheat germ agglutinins and concanavalin A) were also demonstrated. Criteria for diagnosis of malignant histiocytic tumors and differential diagnosis are discussed.     

Angiomatoid malignant fibrous histiocytoma. Clinico-pathologic and immunohistochemical study of a case

The results of a clinico-pathologic and immunohistochemical study of an angiomatoid malignant fibrous histiocytoma are reported. This lesion is an uncommon tumor of the superficial soft tissue, of low-grade malignancy, typical of adolescence and early adult life. The patient, a 10-year-old female, presented with a mass of the left popliteal fossa, treated with surgical excision of the tumor and the surrounding cutaneous and subcutaneous tissue. The tumor was a well-circumscribed, firm nodule measuring 2.5 x 1.0 cm. Histologically, it showed aggregates of spindled and rounded cells often lining cystic cavities filled with blood. The immunohistochemical analysis revealed a cytoplasmatic immunoreactivity for KP1 (CD68), which was taken as indicating that the tumoral mesenchymal cells had acquired phagocytic capacities. The patient is well without signs of local recurrence or metastatic disease 4 years after the surgical treatment. The case reported confirms that appropriate local surgery is the elective therapy for this type of soft tissue tumor.     

Epithelial-myoepithelial carcinoma of parotid gland: a case report with immunohistochemical and ultrastructural studies

A 66-year-old man presented with a painless mass of the parotid gland. Light and electron microscopic studies verified the basic nature of the tumor as epithelial-myoepithelial carcinoma, a low-grade malignant neoplasm of the salivary gland. Pathologically, there were two types of cells; the inner eosinophilic epithelial cells lining the ducts and the outer clear cells. The former cells displayed immunoreactivity for cytokeratin and ultrastructural features of apical microvilli and desmosome. The latter cells were positive for actin, S-100 protein, vimentin and the cytoplasm contained actin microfilaments. Such pathological findings were characteristic features of this rare tumor. To our knowledge, this is the first reported case of EMC in Thailand.     

Oligodendroglioma with signet-ring cell morphology: a case report with an immunohistochemical and ultrastructural study

Clinical reports have suggested an unusual frequency in the number of patients with food allergy to snails who are also allergic to the house-dust mite (HDM). As allergy to HDM is one of the most frequent sensitizations in atopic patients of Western countries, evaluation of the relevance of the concomitant sensitization to Dermatophagoides pteronyssinus and to snails is an important consideration. To evaluate the responsibility of different snail components and of snail mites for inducing in vivo hypersensitivity in patients allergic to HDM, the in vivo reactivity of patients with clinical symptoms after ingestion of snails was assessed by skin prick tests with extracts and hemolymph from four different Helix species snails, and extracts from the snail parasitic mite, Riccardoella limacum. In addition, to obtain epidemiologic data on cosensitization to HDM and snails in allergic patients, the frequency of snail sensitization and its relationship to HDM sensitization were determined in a population of 169 allergic children. All patients allergic to snails had positive skin prick tests to the snail extracts and none to R. limacum extract. The number of positive skin reactions did not significantly differ whatever the species, snail part, or heating procedure used. The strongest reactions were obtained with Helix pomatia (Burgundy snail). Among the 169 prospectively tested children, 38 had a positive prick test to snail extracts; 79% of the snail-sensitized children had sensitization to HDM; and 31% of the children allergic to HDM were found to be sensitized to snails. These results show that snail components, and not the mite R. limacum, were responsible for the in vivo hypersensitivity. These snail components reacting in vivo are present in different parts of snails, including the hemolymph. One-third of the children allergic to HDM were sensitized to snails without any previous ingestion of snails: this observation suggests that HDM was the sensitizing agent and that the cross-reaction could be clinically relevant in countries where eating snails is common.     

Primary renal angiosarcoma: a case report with immunohistochemical, ultrastructural, and cytogenetic features and review of the literature

Primary angiosarcoma of the kidney is a rare tumor for which fewer than 10 case reports appear in the English literature. A case of primary renal angiosarcoma is reported, in which the tumor showed poorly differentiated spindled sarcoma admixed with typical angiomatous differentiation. Antibodies against CD31, CD34, Ulex europeus lectin type I, factor VIII-related antigen, cytokeratin (AE1/AE3), vimentin, S100 protein, epithelial membrane antigen, carcinoembryonic antigen, desmin, and smooth muscle actin were examined. CD31 showed strong diffuse membranous staining of cells in the well-differentiated areas and strong membranous staining in the spindled, poorly differentiated areas. CD34 showed strong cytoplasmic and membranous staining in both the poorly differentiated and well-differentiated areas. Staining for factor VIII-related antigen and Ulex europeus was less intense and was limited to the well-differentiated areas. Staining for cytokeratin (AE1-AE3), S100, carcinoembryonic antigen, epithelial membrane antigen, desmin, and smooth muscle actin were negative. Electron microscopy showed spindle cells containing abundant pinocytotic vesicles, vimentin-type intermediate filaments, and rare Weibel-Palade bodies. A complex karyotype was found. Our findings suggest that CD31 and CD34 are useful in defining endothelial differentiation in poorly differentiated angiosarcomas in which reactions for Ulex europeus lectin type I and factor VIII-related antigen may be equivocal.     

Metastasizing placental site trophoblastic tumor. An immunohistochemical and flow cytometric study of two cases

An immunohistochemical and flow cytometric DNA study of two cases of metastasizing placental site trophoblastic tumor are presented. One patient aged 29 died rapidly of widespread metastases despite hysterectomy and multiagent chemotherapy. The patient had a low level of serum HCG. The course was complicated by the presence of a nephrotic syndrome. The other patient aged 34 had a vaginal metastasis and high levels of serum HCG, and was alive without disease for 9 years after hysterectomy and chemotherapy. Histologically, these tumors were characterized by a monomorphic trophoblastic cell population, probably derived from intermediate trophoblast in the placental site. The mitotic rate in these tumors was 2-4/10 high-power fields. Immunohistochemically, many tumor cells contained human placental lactogen and placental alkaline phosphatase. Beta-unit chorionic gonadotropin was present in many cells of the second patient, and only focally in the first. All specimens including the curettaged and metastatic lesions revealed a diploid DNA content in both cases. Neither DNA ploidy nor S-phase fraction was associated with survival of patient. Since predicting the biologic behavior of placental site trophoblastic tumor is very difficult, making a correct diagnosis on endometrial curettings, hysterectomy, and monitoring serum HCG level is essential in patients with this tumor.     

Perineurial malignant peripheral nerve sheath tumor (MPNST): a clinicopathologic, immunohistochemical, and ultrastructural study of seven cases

Most malignant peripheral nerve sheath tumors (MPNST) are schwannian in nature. The pathologic features of MPNST with perineurial cell differentiation remain to be characterized. To determine the clinicopathologic, immunohistochemical, and ultrastructural characteristics of perineurial MPNST, 121 MPNST from the Mayo Clinic Tissue Registry were examined. Of these 23 spindle cell tumors with long processes disposed in whorls or storiform patterns, features typical of perineurioma, were studied. On the basis of immunohistochemistry (epithelial membrane antigen+/S-100-), 5 perineurial MPNST were identified among 23 tumors selected. These and two previously characterized perineurial MPNST are the subject of this study. None of seven tumors was associated with NF-1. Patients included five males and two females ranging in age from 11 to 83 years (mean, 45.7 years). The tumors measured 1.5 to 30 cm (mean, 9.1 cm) and arose in the extremities (two), trunk (two), face (one), mediastinum (one), and retroperitoneum (one). Only one tumor was nerve associated (phrenic nerve). All tumors were surgically removed. No encapsulation or neurofibroma components were noted. Necrosis was seen in three lesions. Four tumors were classified as high-grade malignant and three as low grade. Mitotic indices varied from 1 to 85/10 high-power fields (median, 16). Immunoreactivities included epithelial membrane antigen (100%), vimentin (100%), Leu-7 (57%), and CD34 (14%). Stains for S-100 protein, muscle markers, and cytokeratin were nonreactive. Ultrastructurally, perineurial-like cells were noted in three tumors and cells intermediate between perineurial and Schwann cells in one. Four tumors recurred and two metastasized; no deaths of disease were noted at follow-ups of 28 to 98 months (mean, 66.9). In conclusion, 4% of MPNST show perineurial cell differentiation. An NF-1 association has yet to be described. Nerve involvement is infrequent. Their immunophenotype (epithelial membrane antigen+/S-100-) frequently indicates ultrastructural perineurial differentiation. The prognosis of perineural MPNST appears to be more favorable than that of conventional MPNST.     

Adenosquamous carcinoma of the tongue: report of a case with histochemical, immunohistochemical, and ultrastructural study and review of the literature

The histologic examination of dental implants retrieved from humans is important to establish the causal determinants of implant failure, and to compare and validate the results obtained from animal studies. This study presents a retrospective review of the histologic features of 230 implants retrieved in an 8-year period (1989-1996). All the implants were treated to obtain thin (20 to 30 microm) ground sections. The majority of implants were retrieved because of mobility (n=56), peri-implantitis (n=54), or fractures (n=90). Peri-implantitis occurred more frequently before (n=44) than after (n=10) abutment connection. A dense fibrous connective tissue with no inflammatory cells was present at the interface in the implants retrieved for mobility; bone was found only in the most apical part. In many of these implants epithelial cells were present. The main histologic features of peri-implantitis consisted of the presence of a bone sequestrum near the implant, many bacteria present on the implant surface, and an inflammatory infiltrate (macrophages, lymphocytes, and plasma-cells) nearby. Histology showed that in the implants removed for fracture, there was a very high percentage (80 to 100%) of peri-implant bone.     

Solitary fibrous tumor of soft tissue: a report of 15 cases, including 5 malignant examples with light microscopic, immunohistochemical, and ultrastructural data

We describe 15 soft tissue solitary fibrous tumors (SFTs) occurring in patients 24 to 78 years old (average, 50.6 yr). Ten tumors were benign and arose in the head and neck area (three tumors), thigh (two), vulva (two), upper arm (one), lower leg (one), and retroperitoneum (one). Five tumors were histologically malignant and arose in the thigh (two), abdominal wall (one), buttock (one), and retroperitoneum (one). All of the tumors were grossly well circumscribed. The benign tumors measured from 2 to 10 cm (average, 4.8 cm) and the malignant ones from 3 to 5.5 cm (average, 4.3 cm) in greatest diameter. Microscopically, the benign tumors showed areas of hypercellularity with variable amounts of collagenous and myxoid stroma; one had amianthoid fibers. The malignant tumors were composed of cytologically atypical cells enmeshed in a collagenous or myxoid extracellular matrix. Ultrastructural study of three benign and three malignant tumors showed fibroblastic differentiation; one benign tumor showed myofibroblastic differentiation. Immunohistochemically, all of the tumors examined were immunoreactive for vimentin, and seven of nine were positive for CD34, including all of the malignant ones. There was focal staining for muscle actin in two benign tumors and for Leu-7 in one benign tumor; there was no staining for cytokeratin, desmin, S-100 protein, epithelial membrane antigen, or smooth muscle actin in any of the examined tissues. Follow-up was available for eight patients for 6 to 21 months (average, 12 mo). No tumor recurred locally or metastasized. The SFTs reported herein support the experiences of others who recently described these tumors in the somatic soft tissues. In addition, our series highlights the occurrence of malignant SFTs in the soft tissues. SFTs should be separated from other spindle cell sarcomas, with which they can be confused.     

Malignant rhabdoid tumor of the vulva: case report with cytological, immunohistochemical, ultrastructural and DNA ploidy studies and a review of the literature

A case of malignant rhabdoid tumor of the vulva in a 25-year-old female was examined. The patient presented with a subcutaneous nodule in the left labium majus. Smears of the material obtained by percutaneous fine-needle aspiration demonstrated clusters of atypical cells with prominent nucleoli. The tumor measured 6 x 5 x 5 cm and appeared tan to brown on the cut surface and partly cystic. Pathological findings obtained from intraoperative frozen tissue sections had been originally interpreted as rhabdomyosarcoma. Light microscopic examination revealed that polygonal tumor cells having vesicular nuclei with prominent nucleoli were arranged in sheets and the great majority of the tumor cells contained an eosinophilic globular paranuclear cytoplasmic inclusion. Ultrastructurally, this cytoplasmic inclusion corresponds to whirls of intermediate filaments. Vimentin immunoreactivity was detected in both the cytoplasm and cytoplasmic inclusion of almost all the tumor cells. No cytokeratin and desmin immunoreactivity were detected in the tumor cells. The Ki-67 labeling index was 36% and the DNA content of the tumor cells, which was examined by image cytometry, demonstrated diploidy (DNA index = 0.95).     

Chondrosarcoma of the urinary bladder: report of a case with immunohistochemical and ultrastructural findings and review of the literature

A primary chondrosarcoma arising in the urinary bladder is described in a 73-year-old female, together with a review of the 2 previously reported cases in the literature. The clinical symptoms are similar to transitional cell carcinoma, but chondrosarcoma usually presents at an advanced stage, and the outcome is rather poor. This very rare and commonly poorly differentiated tumor should not be confused with poorly differentiated transitional cell carcinoma. The differential diagnosis from other lesions with chondroid features, such as chondroid metaplasia, osteosarcoma and carcinosarcoma, is discussed. The value of immunohistochemistry and electron microscopy in the differential diagnosis is demonstrated.     

Malignant rhabdoid tumor of the small intestine in an adult: a case report with immunohistochemical and ultrastructural findings

The expression of platelet-derived endothelial cell growth factor (PD-ECGF) was determined immunohistochemically in 143 non-small cell lung carcinomas. Staining was observed in 48% of the cases. A relationship between histology, stage, erbB-1, erbB-2, ras and PD-ECGF expression was not found. A relationship of borderline significance was observed between PD-ECGF and p53 expression. There was also no relationship between PD-ECGF expression and proliferative activity (G1 phases, S phases, cyclin A). In contrast, a correlation between PD-ECGF- and VEGF-expression was detectable (p=0.009). Furthermore, PD-ECGF expression was related to the response of lung carcinomas to doxorubicin (p=0.0004). Of 35 sensitive tumors, 26 carcinomas were PD-ECGF-positive (74%) while of 108 resistant carcinomas only 43 tumors (40%) exhibited PD-ECGF expression.     

Primary malignant fibrous histiocytoma of the lung. Report of a case with bronchial brushing cytologic features

BACKGROUND: Malignant fibrous histiocytoma (MFH) arising primarily in the lungs is rare, and a preoperative diagnosis, as well as a surgical planning, is very important because of the tumor's propensity for vascular invasion and its low incidence of lymph node metastasis. The correct preoperative diagnosis of thoracic MFH is not easy to establish because the small fragments from needle and transbronchial biopsies are often inadequate for a conclusive histologic analysis. A preoperative bronchial brushing cytology suggestion of the diagnosis of primary MFH of the lungs may be helpful in such cases. CASE: A 37-year-old male presented with a large, irregular mass in the inferior and middle lobes on chest roentgenography as well as on computed tomography. Two bronchoscopies were performed, with the diagnosis of undifferentiated large cell carcinoma. After surgical resection a more sophisticated pathologic analysis, including immunohistochemical and ultrastructural studies, revealed a primary MFH of the lungs. Revision of the bronchial brushing cytology disclosed many spindle-shaped cells with a "comet" configuration, strongly suggestive of MFH. CONCLUSION: The bronchial brushing cytology features of spindle-shaped and bizarre, multinucleated giant cells with a comet appearance may be the key to the cytomorphologic diagnosis of MFH.     

Maternal malignant melanoma metastatic to the products of conception. Report of a case

Beclomethasone dipropionate aerosol at a dose of 100 mug four times a day was administered to 32 patients suffering from chronic perennial asthma. Twenty-three of these patients had previously received prolonged treatment with corticosteroids, causing various degrees of adrenal suppression in some patients. Almost complete recovery of adrenal function was observed within a period of six months in most patients. Treatment with beclomethasone dipropionate did not affect the hypothalamic-pituitary-adrenal axis in the other nine asthmatic patients who had not received prolonged corticosteroid therapy previously and who served as a control group.     

Inclusion body fibromatosis of the breast. Two cases with immunohistochemical and ultrastructural findings

Two cases of fibromatosis of the breast, characterized by a proliferation of spindle cells containing intracytoplasmic, spherical, eosinophilic inclusion bodies, are reported. The light and electron microscopic features, as well as the immunohistochemical features, are indistinguishable from those found in infantile digital fibromatosis. The proliferating spindle cells are characterized as myofibroblasts, whereas the inclusion bodies show an immunohistochemically nonreactive, hollow-like pattern with peripheral reactivity for actin filaments. This lesion, observed for the first time in the breast, expands the number of extradigital inclusion body fibromatoses.