An extragonadal yolk sac tumor presumed to be of postmeiotic germ cell origin by genetic zygosity analysis via single nucleotide polymorphism array

An extragonadal yolk sac tumor (YST) is a rare malignant germ cell tumor that usually occurs in childhood. The pathogenesis of extragonadal YST remains largely unknown, especially with regards to its cell of origin. Herein, we report a case of extragonadal YST arising in the uterine round ligament. A 31‐year‐old Japanese woman, para 2, underwent partial resection of a left‐sided, 5‐cm, solid inguinal mass. Intraoperative findings showed enlargement of the uterine round ligament in the inguinal canal. Pathological evaluation diagnosed the mass as YST with a mature teratoma (MT) component. The preoperative α‐fetoprotein level was markedly elevated, at 24 790 ng/mL. Postoperative magnetic resonance imaging revealed a right ovarian MT and a 3‐cm mass remaining in the left lower abdominal wall. The patient underwent total abdominal hysterectomy, bilateral adnexectomy, and left inguinal mass resection. We sampled three frozen tissues (YST, right ovarian MT, and left normal ovary) and performed a single nucleotide polymorphism (SNP) array. Pathological evaluation revealed remnant extragonadal YST in the left inguinal region. The SNP array demonstrated a completely homozygous YST genotype. Copy number variations were gains of 1p, 1q, 2p, 3p, 7p, 8p, 10q, 14q, 18p, 20q, Xp, and Xq and losses of 12q, 20p, and Xq. The right ovarian MT and left normal ovary were partially homozygous and heterozygous, respectively. The evidence suggests that this neoplasm is presumed to be a postmeiotic germ cell origin.     

Retroperitoneal liposarcoma presenting a indirect inguinal hernia

A 60-year-old man was admitted to our hospital with a right inguinal swelling that had been growing in size without any pain for 7 months. We diagnosed the growth as a right inguinal hernia and operated on him. The growth, however, was found to be a tumor it situated along the spermatic cord and testicular vessels. We diagnosed it as a lipoma. The tumor was resected near part of the internal inguinal ring. Histopathological diagnosis showed well-differentiated liposarcoma of the sclerosing type. Postoperative computed tomography (CT) revealed a large residual tumor in the retroperitoneum. We believed that the tumor was a retroperitoneal liposarcoma and that it developed in the inguinal region. The residue of the liposarcoma was resected onto the right inguinal tract. A periodic follow up has been performed and no evidence of recurrence or metastasis has been seen in the 4 years and 9 months since the second surgery. No adjuvant therapy was performed. Inguinal liposarcomas are relatively rare and in most cases these tumors are thought to originate in the spermatic cord. The origin of the tumor is believed to be the retroperitoneum.     

Mammary-type myofibroblastoma of soft tissue

A 40-year-old woman presented with a 1 year history of a painless, subcutaneous lump on the right buttock. Clinical examination showed an approximately 6 cm large subcutaneous mass covered by apparently normal-looking skin. No inguinal lymphadenopathy was found. The mass was excised with the clinical diagnosis of fibroma. Histologically, the lesion was consistent with mammary-type myofibroblastoma of soft tissue, a very rare, benign mesenchymal neoplasm with myofibroblastic differentiation. After surgical excision she was free of recurrence over a period of 8 months. This article also challenges the theory that suggests the origin of this tumor to be from the embryonic mammary tissue, adding another case of a site other than the milk lines.     

Mixed testicular germ cell tumor in an adult with cryptorchidism and Down's syndrome

We here present a case of mixed testicular germ cell tumor in an adult with cryptorchidism and Down's syndrome. A 20-year-old Japanese man with a mass in the left inguinal region underwent orchidectomy as a left testicular tumor was suspected. Histology showed a mixed germ-cell tumor with embryonal carcinoma and yolk sac tumor with syncytiotrophoblastic giant cells occurring in a cryptorchid testis. Chromosomal analysis of peripheral lymphocytes disclosed a karyotype of 47,XY,+21[20]. Our case provides further evidence that these three conditions-Down's syndrome, cryptorchidism and testicular germ cell tumor-may be closely associated. To our knowledge this is the first case of mixed germ cell tumor arising in a patient with Down's syndrome and cryptorchidism.     

Solitary fibrous tumor of soft tissue: a case report and immunohistochemical study

A case of solitary fibrous tumor (SFT) arising in the soft tissue of the left inguinal region is reported. A 57-year-old Japanese woman presented with a nonadherent, well-defined, oval mass that was 2 × 3 cm in diameter and located in the inguinal soft tissue. Microscopic evaluation showed proliferation of spindle-shaped, fibroblast-like cells by the coexistence of hypo- and hypercellular areas with mast cell infiltration separated by hemangiopericytoma-like blood vessels. Immunohistochemistry revealed strong expression of CD34 and CD99 in the fibroblast-like cells, supporting the diagnosis of SFT. Although the patient was free of symptoms such as hypoglycemia, immunoreactive insulin-like growth factor (IGF)-II was localized in the socalled Golgi area of the spindle-shaped cells. In conclusion, immunoreactive IGF-II was detected in SFT that was not associated with hypoglycemia.     

An undifferentiated sarcoma in a rat resembling extraskeletal myxoid chondrosarcoma in man

A soft tissue tumor occurring in the inguinal subcutaneous tissue was detected in a 109-week-old male F344 rat. Macroscopically, the tumor mass showed no skeletal relationship and a gelatinous multinodular appearance. Histologically, the tumor consisted of irregular lobules separated by scant fibrous septa. In each lobule, tumor cells were arranged in cords and strands in the plentiful myxoid stroma. The tumor cells showed marked pleomorphism, and had large, round to ovoid nuclei and abundant eosinophilic cytoplasm. Mitotic figures were often seen. Myxoid stroma of the tumor contained a large amount of acid mucopolysaccharides and collagen type II, which were demonstrated by histochemistry and immunohistochemistry respectively. The tumor cells showed positive immunoreactivities for vimentin and S100 protein. Ultrastructural examination revealed that the tumor cells had a large amount of mitochondria, Golgi complex and dilated rough endoplasmic reticulum containing amorphous material, and the myxoid stroma contained collagenous fibrils and proteoglycan particles. Based on these results, the present tumor in a rat resembled extraskeletal myxoid chondrosarcoma in man.     

Sclerosing extramedullary hematopoietic tumor presenting as an inguinal mass in a patient with primary myelofibrosis: a diagnostic pitfall

Sclerosing extramedullary hematopoietic tumor (SEMHT) is a rare lesion and presented as retroperitoneal or serosal-based mass. A 53-year-old man with a long history of primary myelofibrosis, presented with abdominal distension and inguinal mass. Pathologic examination of inguinal mass revealed a prominent sclerotic background with thick collagen deposits and mono, bi, or tri-lineage hematopoietic tissue containing atypical megakaryocytes and variable proportions of myeloid and erythroid series. The atypical megakaryocytes were positive for Factor VIII and CD61. SEMHT may be misdiagnosed as lymphocyte depleted Hodgkin’s disease, as a mesenchymal neoplasm, or as carcinoma, because of the presence of large atypical cells and marked fibrosis when clinical information regarding PMF is unknown. Awareness of the bizarre atypical megakaryocyte morphology with immature hematopoietic cells and of clinical history is essential to prevent misdiagnosis.     

Angiomyofibroblastoma of the male inguinal region

We present a case of benign angiomyxoid tumor arising in the inguinal region of a 27-year-old man. The tumor was a gelatinous mass completely encapsulated by a thin fibrous capsule with no hemorrhage or necrosis. Histologically, a proliferation of spindle cells as well as occasional pleomorphic cells was observed within the myxofibrous stroma, intermingled with abundant capillary-sized blood vessels. Immunohistochemical staining of the tumor demonstrated spindle, oval, and pleomorphic cells equally positive for vimentin, desmin, and CD34, but not for alpha-smooth muscle actin. Based on these histologic and immunophenotypic features, we conclude that this angiomyxoid tumor of the male inguinal region is indistinguishable from the female angiomyofibroblastoma of the pelvic and perineal regions.     

Inguinal canal "lipoma"

Groin dissection was performed in adult male post-mortem subjects to establish the prevalence of inguinal canal "lipoma." Thirty-six body halves (age range 24-92 years) were studied. Of these, 27 (75%) contained a discrete mass of fat within the inguinal canal. This mass was always continuous with the preperitoneal fat through the deep inguinal ring. Nineteen of these 27 masses (70%), displayed a characteristic pedunculated form with a bulbous distal end. Eighteen of the 36 dissections (50%), revealed a mass more than 4 cm in length. Six dissections showed extension of the mass beyond the superficial inguinal ring and three of these six (8% of the 36 groins studied) showed distortion of the proximal spermatic cord with a mass at the superficial inguinal ring. The masses submitted for histology comprised mature adipose tissue and all but two of these were reported as having an adherent capsule. No significant correlation was found between mass length and either subject age or body mass index (BMI) but a statistically significant correlation between the length of the fat mass on the left and right sides was shown. This study demonstrates that the inguinal canal "lipoma" is a common feature in an adult male population and may be of sufficient size to cause clinical misdiagnosis. The high prevalence, characteristic location and appearance of the "lipoma" suggest a developmental etiology.     

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region of a 31-year-old Japanese male is reported. The tumor grew rapidly and appeared as a large mass measuring 21.5 X 16.5 cm located in the subcutaneous tissues of the lower abdominal wall. Histologically the tumor was composed of small round cells resembling rhabdomyoblasts, which showed a diffuse or alveolar arrangement. The cytoplasm of the tumor cells was eosinophilic and frequently contained round inclusion bodies, each consisting of an aggregation of globular filaments by electron microscopy. Immunohistochemistry showed the tumor cells to be positive for vimentin and keratin in the cytoplasm, but negative for actin, myoglobin and myosin. At autopsy, extensive metastatic or invasive tumors were observed mainly in the retroperitoneum and pelvic organs. The patient showed hypercalcemia which disappeared for only short periods just after surgery.     

Giant cell angiofibroma of the inguinal region

Giant cell angiofibroma is a rare mesenchymal neoplasm most commonly arising in the soft tissues near the orbit. Recently, several cases of extraorbital giant cell angiofibroma have been reported. We report the light microscopic and immunohistochemical features of an additional case of extraorbital giant cell angiofibroma arising in the inguinal region that was clinically mistaken for an inguinal hernia. The patient was a 50-year-old woman who presented with a mobile, nonreducible, left inguinal mass. The tumor was 10.8 cm in greatest diameter, was well circumscribed, and appeared to be encapsulated. Histologically, the tumor was composed of a mixture of cytologically bland spindle-shaped cells and ovoid cells of varying cellularity with deposition in a variably collagenous and myxoid stroma. The tumor had prominent, various-sized blood vessels, often with perivascular hyalinization. In addition, scattered pseudovascular spaces filled with an amorphous eosinophilic material were present and lined by spindle-shaped and ovoid cells similar to those found throughout the neoplasm. Rare multinucleated floret-like giant cells were seen. Immunohistochemically, the tumor cells stained strongly and diffusely for both CD34 and bcl-2 while immunostains for S-100 protein, desmin, smooth muscle actin, and muscle-specific actin were negative. There is no evidence of local recurrence or metastasis 3 months following excision of the mass. This report emphasizes the recognition of this unusual tumor in extraorbital sites. We discuss the overlapping histologic and immunophenotypic features with giant cell fibroblastoma and solitary fibrous tumor and raise the possibility that these tumors could represent a histologic spectrum of CD34-positive dendritic interstitial cell neoplasms.     

AN AUTOPSY CASE OF MALIGNANT RHABDOID TUMOR ARISING FROM SOFT PARTS IN THE LEFT INGUINAL REGION

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region of a 31-year-old Japanese male is reported. The tumor grew rapidly and appeared as a large mass measuring 21.5 × 16.5 cm located in the subcutaneous tissues of the lower abdominal wall. Histologically the tumor was composed of small round cells resembling rhabdomyoblasts, which showed a diffuse or alveolar arrangement. The cytoplasm of the tumor cells was eosinophilic and frequently contained round inclusion bodies, each consisting of an aggregation of globular filaments by electron microscopy. Immunohistochemistry showed the tumor cells to be positive for vimentin and keratin in the cytoplasm, but negative for actin, myoglobin and myosin. At autopsy, extensive metastatic or invasive tumors were observed mainly in the retroperitoneum and pelvic organs. The patient showed hypercalcemia which disappeared for only short periods just after surgery. ACTA PATHOL JPN 38: 1087∼1096, 1988.     

Malignant large cell calcifying Sertoli cell tumor of the testis

A 45-year old man presented with a slow-growing, unilateral beige testicular mass, with a diameter of 4 cm. The testosterone, FSH, LH, estradiol and betahCG serum levels were within normal limits, and there were no associated hormonal syndromes. The patient was treated with inguinal orchidectomy. Microscopically, the tumor was composed of nests of cells with large eosinophilic, slightly granular cytoplasm. There was only a mild degree of atypia and no mitotic activity. The tumor extended into the rete testis. There were intratumoral calcifications, and in the vicinity of the tumor, there was intratubular growth. Although this case is histologically similar to the three previously reported cases of clinically benign large cell calcifying Sertoli cell tumor of the testis with rete testis involvement, the current patient developed right sided para-aortic lymph node metastases 18 months after the initial diagnosis.     

Hurthle cell adenoma of the mediastinum: intraoperative cytology and differential diagnosis with correlative gross, histology, and ancillary studies

A 66-year-old man was found to have a 7.5 cm mediastinal mass detected on routine chest X-rays as part of his preoperative work up for an inguinal hernia repair. An orthotopic (normally located) nongoitrous thyroid gland without evidence of connection to the mediastinal mass was also identified. The clinical differential diagnoses included lymphoma, thymoma, and germ cell tumor. Fine-needle aspiration (FNA) biopsy smears and touch imprints of the mediastinal mass showed a loosely cohesive, highly cellular population of relatively uniform cells with abundant granular cytoplasm, low nuclear to cytoplasmic (N/C) ratios, and prominent nucleoli consistent with a Hurthle cell (HC) neoplasm. Subsequently, the diagnosis of HC adenoma was confirmed on the surgically excised mediastinal mass. To the best of our knowledge, the surgical pathology and cytologic features of an HC adenoma of the mediastinum have not been reported in the literature. The gross, histologic, immunohistochemical, and electron microscopic (EM) findings, in addition to the cytologic features, are presented along with a differential diagnosis of this mediastinal neoplasm.     

Plasmablastic lymphoma of the retroperitoneum in an HIV‐negative patient

Herein is reported a case of plasmablastic lymphoma (PBL) of the retroperitoneum in an HIV‐negative patient. This is the first reported case of PBL at this location and of PBL from Japan in the English‐language literature. A 76‐year‐old Japanese man was admitted to hospital with a chief complaint of right inguinal lymph node swelling. Lymph node biopsy indicated large tumor cells with both diffuse and cohesive growth patterns, and conspicuous tumor cell proliferation in lymph node sinuses. The initial pathological diagnosis was metastatic carcinoma. The patient died approximately 1 month after admission, and autopsy showed that the main lesion was a very large retroperitoneal mass. On histology diffusely proliferated plasmablast‐like or immunoblast‐like tumor cells were identified, which were positive on immunohistochemistry for CD138 and negative for B‐cell and epithelial markers. Approximately 90% of the tumor cells were positive for Ki‐67. Tumor cells were diffusely positive for EBV‐encoded small RNA on in situ hybridization. The autopsy findings suggested a diagnosis of PBL. Accordingly, PBL should be considered as a differential diagnosis when lymph node biopsy findings resemble those of the present patient.     

Primary lymph node plasmocytoma of IgD-class

An extramedullary plasmocytoma in a right inguinal lymph node was observed in a 62-year-old woman. The tumor showed monoclonal proliferation of plasma cells which revealed highly positive stainings of both IgD and lambda light chain using the PAP-technique. Monoclonal IgD-lambda was also secreted in serum and urine. Clinical data, lymphography and bone biopsy showed a tumor spreading in the right inguinal, left iliacal and lumbar regions without systemic involvement of bone. In contrast to extramedullary plasmocytomas of other immunoglobulin classes the disease progressed rapidly and the patient died 8 months after the onset. The present case is the first reported IgD-plasmocytoma in lymph nodes.     

Metastatic myxopapillary ependymoma: Report of a case with fine-needle aspiration findings

A case of recurrent and metastasizing myxopapillary ependymoma of the sacral region in a 35-yr-old man is reported. Fifteen years after the original diagnosis, he presented with an abdominal mass, subcutaneous nodules in the previous surgical excirion line, and bilateral inguinal lymph node enlargement. FNA cytology of the inguinal lymph nodes showed a poorly cohesive, highly cellular smear pattern exhibiting papillary formations and rosette-like structures composed of slim columnar cells having cytoplasmic processes without evidence of atypia. Histologic and ultrastructural findings confirmed the diagnosis. Chromosomal analysis was also done. © 1994 Wiley-Liss, Inc.     

Ulcerating rheumatoid nodule of the vulva.

A case of an ulcerating rheumatoid nodule of the vulva in a 76 year old woman with rheumatoid arthritis complicated by Felty's syndrome is reported. The patient presented with a mass in the vulval region. On clinical examination, she had an ulcerated mass associated with inguinal lymphadenopathy. These findings resulted in a clinical diagnosis of invasive carcinoma of the vulva and an excision biopsy was carried out. On microscopic examination, the lesion showed the characteristic features of a rheumatoid nodule with ulceration of overlying epidermis. Adjacent vessels showed inflammation and fibrinoid necrosis of their walls suggestive of a vasculitis. Awareness of the possibility of ulceration in rheumatoid nodules may facilitate diagnosis and avert unduly aggressive treatment.     

Clear-cell epithelioid leiomyoma of the round ligament.

A case of clear-cell epithelioid leiomyoma of the round ligament in a 69-year-old woman is described. The neoplasm presented as a firm left inguinal mass. A preoperative computed tomography (CT) scan demonstrated an enhancing lesion extending extra-abdominally from the region of the external inguinal ring. The surgical resection specimen was tan-white, well-circumscribed, and measured 5.8 cm in maximum dimension. Microscopic examination revealed a well-demarcated neoplasm comprised of polygonal cells with abundant clear cytoplasm arranged in clusters and single files with abundant intervening hyalinized stroma. There was minimal nuclear atypia and mitotic figures were rare. Periodic acid-Schiff with diastase demonstrated intracytoplasmic glycogen. Immunohistochemical stains for pan-actin, smooth muscle actin, desmin, bcl-2, and vimentin were positive in the tumor cells, whereas stains for CD34, carcinoembryonic antigen, cytokeratin, epithelial membrane antigen, S100 protein, and neurofilaments were negative. Electron microscopy demonstrated features of smooth muscle differentiation including longitudinally oriented fine filaments with focal condensations, pinocytotic activity, and subplasmalemmal densities. This case illustrates the ubiquitous distribution of epithelioid smooth muscle neoplasms and highlights the potential pitfalls for diagnosis when they occur in an unusual location.