Capillary hemangioblastoma of soft tissue: report of a case and review of the literature

Perivascular Epithelioid Cell Tumor of the Lung With a Novel YAP1::TFE3 Fusion

Perivascular epithelioid cell tumor (PEComa) belongs to a family of rare mesenchymal neoplasms that share characteristic morphologic, immunohistochemical and molecular findings. In this report, we provide a detailed clinicopathological characterization of a PEComa incidentally discovered in the right lung of a 53-year-old woman. This tumor with epithelioid cell morphology and myomelanocytic differentiation demonstrated a TFE3::YAP1 fusion by targeted RNA sequencing. While a subset of PEComas shows TFE3 rearrangements, fusion with YAP1 has not been systematically documented in this entity. Clear cell stromal tumor of the lung and epithelioid hemangioendothelioma characteristically display the TFE3::YAP1 fusion; however, as currently defined, both lack myomelanocytic features. Here, we describe a novel TFE3 fusion partner that further expands the spectrum of molecular alterations seen in PEComa.

Clinicopathological analysis of extraneural sporadic haemangioblastoma occurring in the tongue

Haemangioblastoma is a morphologically distinctive tumour with uncertain histogenesis, typically occurring in the cerebellum, brain stem or spinal cord and less commonly in extraneural locations. Here, we present a case of haemangioblastoma occurring in the tongue, which is the first reported case in terms of the pathogenic site. The tumour was morphologically indistinguishable from central nervous system haemangioblastoma, that is, neoplastic stromal cells with cytoplasmic vacuolisation and abundant small vessels. Immunohistochemical studies revealed that the tumour cells were positive for S100, NSE, CD56, Syn, EMA, vimentin and α-inhibin, while negative for CK, SMA, factor Ⅷ, D2-40 and GFAP. Immunostainings for CD34 and CD31 outlined the rich and delicate vascular channels. Ki-67 expression was presented in approximately 3% of tumour cells. Primary haemangioblastoma has not been previously described at this site, and this case emphasises the need to consider haemangioblastoma in the differential diagnoses of neoplasms occurring in the tongue.

CT and MRI characteristic findings of sporadic renal hemangioblastoma: Two case reports

RATIONALE

Hemangioblastomas in the kidney are rare. Although a few cases of renal hemangioblastoma (RH) have been reported, the content of these articles mainly focused on clinical and pathological research, with minimal descriptions of radiologic findings. Moreover, there are no descriptions of magnetic resonance imaging (MRI) with enhancement of this condition. Herein, we report 2 cases of RH with computed tomography (CT) and MRI findings.

PATIENT CONCERNS

Two patients presented to our institution because of dull pain in the left abdomen, and a mass in the left kidney was found by ultrasound examination in each case. The patient had no special family history. Physical examination revealed no obvious tenderness or percussion pain in the renal and ureteral walking areas, and there was no obvious mass. Routine blood and urine tests were normal, and the serum tumor markers were negative. No obvious lesions were found on imaging of the other body parts.

DIAGNOSIS

Similar radiologic findings were observed in both cases and mimicked those of cavernous hemangiomas of the liver, including peripheral nodular enhancement in the corticomedullary phase, progressive centripetal enhancement in the nephrographic and delayed phases, and occasional complete "filling in" in the delayed phase. We made a radiologic diagnosis of renal clear cell carcinoma for patient 1 and suspected renal clear cell carcinoma for patient 2, but the pathological results showed RH.

INTERVENTIONS

Given the suspicion of renal cell carcinoma, both patients underwent partial nephrectomy.

OUTCOME

The recovery of the two patients was uneventful, and there was no evidence of local recurrence or metastasis many years after surgery.

LESSONS

RH is a rare benign tumor that can be easily misdiagnosed as clear cell carcinoma. Characteristic CT and MRI manifestations may improve preoperative diagnostic accuracy to avoid surgery or indicate nephron-sparing surgery.

Extraneuraxial Hemangioblastoma: Clinicopathologic Features and Review of the Literature

Extraneuraxial hemangioblastoma occurs in nervous paraneuraxial structures, somatic tissues, and visceral organs, as part of von Hippel-Lindau disease (VHLD) or in sporadic cases. The VHL gene plausibly plays a key role in the initiation and tumorigenesis of both central nervous system and extraneuraxial hemangioblastoma, therefore, the underlying molecular and genetic mechanisms of the tumor growth are initially reviewed. The clinical criteria for the diagnosis of VHLD are summarized, with emphasis on the distinction of sporadic hemangioblastoma from the form fruste of VHLD (eg, hemangioblastoma-only VHLD). The world literature on the topic of extraneuraxial hemangioblastomas has been comprehensively reviewed with ∼200 cases reported to date: up to 140 paraneuraxial, mostly of proximal spinal nerve roots, and 65 peripheral, 15 of soft tissue, 6 peripheral nerve, 5 bone, and 39 of internal viscera, including 26 renal and 13 nonrenal. A handful of possible yet uncertain cases from older literature are not included in this review. The clinicopathologic features of extraneuraxial hemangioblastoma are selectively presented by anatomic site of origin, and the differential diagnosis is emphasized in these subsets. Reference is made also to 10 of the authors' personal cases of extraneuraxial hemangioblastomas, which include 4 paraneuraxial and 6 peripheral (2 soft tissue hemangioblastoma and 4 renal).

Sporadic Retroperitoneal Hemangioblastoma: Report of a Case and Review of the Literature

We report a case of sporadic isolated hemangioblastoma arising from the retroperitoneum and provide a review of the scarce literature regarding this very rare tumor. Furthermore, we thoroughly describe the pathologic features and the broad differential diagnosis that should always be included in the study of any retroperitoneal soft tissue mass to arrive at the final diagnosis.

Extraneural hemangioblastoma of the kidney: the challenge for clinicopathological diagnosis

Background

Hemangioblastoma is a benign cerebellar tumour which may occur as a sporadic entity or in association with von Hippel-Lindau (VHL) disease in approximately 25% of cases. Renal hemangioblastoma (RH) is an extremely rare and newly recognised tumour. Here, we describe five cases of RH, one discovered by CT in an accident and the other four detected during routine examinations.

Methods

Five cases of renal hemangioblastoma retrieved from the Department of Pathology, Fudan University Shanghai Cancer Center were studied and the literatures were reviewed. Immunohistochemistry was used to differentiate and confirm this tumour.

Results

Pathological examination following tumour resection revealed RH in all cases, the first patient was also diagnosed with renal cell carcinoma (RCC), suggesting the possibility of VHL syndrome, but PCR sequencing analysis of the VHL gene confirmed no mutation in any of the three exons, implying sporadic disease .Histologically, the tumours were circumscribed, composed of sheets of oval or polygonal cells and a prominent vascular network. Tumour cells had pleomorphic nuclei, but mitotic figures were rare. The diagnosis of hemangioblastoma was confirmed by immunohistochemistry.

Conclusions

RH is very rare and is challenging to differentially diagnose. Distinguishing RCC and RH is difficult and each has a different prognosis, so differentiating between them is essential for avoiding over-diagnosis and unnecessary treatment.

Primary gastric hemangioblastoma: report of a case

Capillary hemangioblastoma (CHB) is a benign, highly vascularized tumor that generally occurs in central nervous system either in the setting of von Hippel-Lindau (VHL) disease or, more often, as a solitary sporadic lesion that is increasingly recognized in extraneural sites. We present the case of a 18 year-old man with abdominal pain, nausea and hematemesis, the endoscopy showed polypoid tumor bleeding of 5 cm in gastric antrum. The patients had not signs of VHL disease and was subjected to subtotal gastrectomy and referred to our institution. To our knowledge this is the first reported case of CHB occurring in stomach.

Hemangioblastoma in the lung: metastatic or primary lesions?

Hemangioblastoma primarily occurs in the CNS, most commonly in the posterior fossa. Extracranial locations are less common, and metastatic tumor involving the lung is exceedingly rare with only three cases previously reported. Two were autopsy studies in patients who died of complications of the CNS hemangioblastomas in 1943 and 1981, and the third was mentioned in a case report addendum providing follow-up information on hepatic hemangioblastoma in 1991. We report a case of a 48-year-old man who presented with multiple lung nodules treated by surgical excision. Pathological study revealed features classic for hemangioblastoma. The patient had a remote history of hemangioblastomas having been excised from the posterior fossa 7 and 20 years previously. This report details a fourth case of metastatic pulmonary hemangioblastoma. It is the first report on surgically resected hemangioblastomas from the lung of a living patient with histological and immunohistochemical characterization.

Brachyury: a diagnostic marker for the differential diagnosis of chordoma and hemangioblastoma versus neoplastic histological mimickers

Brachyury is a transcription factor which is required for posterior mesoderm formation and differentiation as well as for notochord development during embryogenesis. Due to its expression in the neoplastic cells of chordoma, a malignant tumour deriving from notochordal remnants, but not in tumors showing a similar histology, brachyury has been proposed as a diagnostic marker of this neoplasia. Though commonly considered a hallmark of chordoma, the expression of brachyury has been also documented in the stromal cells of hemangioblastoma (HBL), a slow growing tumor which may involve the central nervous system (CNS) and, rarely, the kidney. Herein we review the role of brachyury immunohistochemical detection in the identification and differential diagnosis of chordoma and HBL towards histological mimickers and suggest that brachyury is added to the panel of immunohistochemical markers for the recognition of HBL in routinary practice, principally in unusual sites.

PAX8 expression in sporadic hemangioblastoma of the kidney supports a primary renal cell lineage: implications for differential diagnosis

Hemangioblastoma is a benign, morphologically distinctive neoplasm of disputed histogenesis that typically occurs in the central nervous system either in the setting of von Hippel-Lindau disease or more often sporadically. Extraneural hemangioblastoma is exceptional and raises a challenging differential diagnosis. Herein, we report a primary renal hemangioblastoma occurring in 51-year-old woman without stigmata of von Hippel-Lindau disease. Histologically, the tumor was composed of sheets of polygonal epithelioid stromal cells with ample pale or eosinophilic, vacuolated cytoplasm in an arborizing capillary network. Tumor cells showed variable nuclear pleomorphism, intranuclear cytoplasmic invaginations, scattered hyaline globules, and psammoma-like calcifications. Some areas showed branching hemangiopericytoma-like vessels with tumor cells radiating from the wall, while other areas were edematous and hyalinized with sparse stromal cells and abundant reticular vessels. Immunohistochemically, the tumor cells reacted strongly and diffusely with antibodies to PAX8, CD10, α-inhibin, S100 protein, neuron-specific enolase, and vimentin, and they showed focal positivity with antibodies to epithelial membrane antigen and AE1/AE3. Tumor cells were negative for CK7, CK8/18, RCC antigen, synaptophysin, chromogranin, c-kit, D2-40, HMB45, melan-A, cathepsin K, SMA, desmin, CD31, CD34, and estrogen and progesterone receptors. Positive immunoreactivity for PAX8 is unexpected and contrasts to central nervous system (CNS) hemangioblastomas, which are essentially always negative for PAX8. This novel finding adds support to the hypothesis that the immunoprofile of extraneural hemangioblastoma varies with site of origin, perhaps as a result of tumor cell lineage and retention of organ-specific markers or acquisition of site-specific antigens due to local factors.

Hemangioblastoma of the gastrointestinal tract: a first case

We present the first documented case of hemangioblastoma located in the left colon. A 75-year-old woman undergoing adjuvant chemotherapy for breast cancer experienced rectal bleeding. Colonoscopy revealed a roundish mass covered with normal mucosa in the sigmoid colon. Endoscopic ultrasound showed an isoechoic lesion originating from the third layer of the intestinal wall; underlying layers were normal. Endoscopic ultrasound features were not suggestive of either cancer or malignant stromal tumor. Left hemicolectomy was subsequently performed due to repeated episodes of lower gastrointestinal bleeding. Grossly, a circumscribed submucosal yellowish nodule (13 mm) was observed, which was not attached to any peripheral nerve. Histologically, the lesion was composed of large, atypical cells traversed by a network of blood vessels. Immunohistochemically, the cells showed positivity for inhibin and NSE and weak positivity for S-100. A diagnosis of hemangioblastoma was made. This case highlights that hemangioblastoma of the gastrointestinal tract can also occur.

Hemangioblastoma-like clear cell stromal tumor of the lung

The authors report 2 cases of an apparently unpublished stromal tumor of the lung characterized by a predominantly endobronchial growth pattern and benign-appearing clear cells. Both tumors were discovered incidentally in adult patients during routine workups for other medical reasons and treated with lobectomy. On gross inspection there was no evidence of infiltration of the adjacent lung tissue. Microscopically, both lesions featured monotonous oval-shaped to spindle-shaped cells growing in a vaguely nested pattern. The cytoplasm was slightly vacuolated or granular. In 1 case there was a variable admixture with mature fat. Immunohistochemistry was negative for markers of epithelial and stromal differentiation except for vimentin. A focal reaction for CD34 was seen in 1 case. No mutation of coding sequence of VHL gene was seen in one case. Medical follow-up at 1 year was negative for tumor recurrence or metastases. The broad differential diagnosis within the spectrum of stromal lung tumor is discussed. Owing to distinctive microscopic features such as the nesting of clear cells within a vascularized background, both tumors appeared similar to hemangioblastoma, although the expected immunohistochemical profile of the latter was not fully expressed. Because of pattern of growth seen in both lesions we believe that the appellation of endobronchial, hemangioblastoma-like clear cell stromal tumor may be provisionally designed.

Adrenal haemangioblastoma presenting as phaeochromocytoma: a rare manifestation of extraneural hemangioblastoma

PURPOSE

Adrenal haemangioblastoma presenting clinically as pheochromocytoma is a rare manifestation of extraneural haemangioblastoma. We present an unusual case of von Hippel-Lindau (VHL) disease that had adrenal and cerebellar haemangioblastoma with multiple renal cysts, and a review of the literature.

METHODS

Unlike the usual manifestations of secondary polycythemia or increased intracranial pressure and hydrocephalus due to cerebellar lesion, this 36-year-old male presented with hypertension. Investigations revealed right suprarenal mass with raised urinary catecholamines and serum vanillylmandelic acid (VMA) levels, apparently confirming the clinical diagnosis of phaeochromocytoma.

RESULTS

Histopathology of the biopsy specimen showed features of haemangioblastoma, which was confirmed by immunohistochemistry using antibodies to neuron specific enolase and aquaporin-1. Based on this, the patient was screened for possible features of VHL, which revealed cerebellar haemangioblastoma and multiple renal cysts with angiomatous lesion. Postoperative follow-up showed normal levels of catecholamines without any symptoms of phaeochromocytoma.

CONCLUSIONS

Adrenal haemangioblastoma is a rare entity with only four cases reported in the literature. Surgical removal is the treatment of choice. However, screening for other possible features of VHL, even in the absence of clinical features, is essential to exclude other potential lesions.

Soft-tissue hemangioblastoma of the retroperitoneum: a case study and review of the literature

A 71-year-old woman was found to have a solid retroperitoneal mass measuring 7 x 6 cm on a computed tomography scan. The tumor was not connected to the spinal cord or large nerves. It was resected and showed the typical histology of hemangioblastoma, that is, numerous capillaries and stromal cells with focal cytoplasmic vacuolization. Immunohistochemical study revealed that the tumor stromal cells were positive for S-100 protein, neuron-specific enolase, and inhibin-α, supporting the diagnosis. In addition, the tumor cells labeled for carbonic anhydrase IX and brachyury. The diffuse strong carbonic anhydrase IX expression suggested that soft-tissue hemangioblastoma may share with central nervous system hemangioblastoma the tumorigenic mechanism involving the von Hippel-Lindau gene product and hypoxia-inducible factor. The brachyury expression observed in this case, albeit focal and weak, may implicate embryonic hemangioblasts as a potential line of differentiation, as was proposed in central nervous system hemangioblastoma. The patient is well 4 years after the surgery without any recurrence. A review of the literature revealed that soft-tissue hemangioblastoma is typically a solid tumor found in older females and often involves the retroperitoneum/pelvis.

Sporadic hemangioblastoma of the kidney: an underrecognized pseudomalignant tumor?

Hemangioblastoma is a benign tumor that can occur sporadically, or in association with von Hippel-Lindau disease in approximately one-quarter of the cases. Only exceptionally does it occur outside the central nervous system. This report describes 2 cases of sporadic renal hemangioblastoma, with 1 patient presenting with hematuria and polycythemia, and the other low back pain. Histologically, the tumors were circumscribed, and composed of sheets of large polygonal cells traversed by arborizing thin-walled blood vessels. Many of the tumor cells showed pleomorphic nuclei, but the mitotic figures were rare. The cytoplasm was eosinophilic, and occasionally finely vacuolated indicating the presence of lipid. The diagnosis of hemangioblastoma was confirmed by negative immunostaining for cytokeratin, and positive staining for α-inhibin, S100, and neuron-specific enolase. This benign neoplasm which can be mistaken for various malignancies such as renal cell carcinoma, epithelioid angiomyolipoma, adrenal cortical carcinoma, and paraganglioma, deserves wider recognition for its occurrence as a primary renal tumor.

Primary Capillary Hemangioblastoma of Bone: Report of a Case Arising in the Sacrum

Capillary hemangioblastoma (CHB) is a benign, highly vascularized tumor that generally occurs in the central nervous system either in the setting of von Hippel-Lindau (VHL) disease or, more often, as a solitary sporadic lesion that is increasingly recognized in extraneural sites. We present the case of a 72-year-old woman with low back pain and a well-demarcated lytic lesion of the sacrum, which at histological and ultrastructural examination was indistinguishable from central nervous system CHB. The patient had no signs of VHL disease and died of another cause with no evidence of disease 57 months after curettage of the lesion. To our knowledge, this is the second case of CHB reported to occur in bone.

Extraneural hemangioblastoma: a report of 5 cases

Hemangioblastoma is a morphologically distinctive tumor that can occur sporadically or in association with von Hippel-Lindau disease, and which involves the central nervous system in the majority of the cases. Rare occurrences of hemangioblastoma in peripheral nerves and extraneural tissues have been reported. The histogenesis of this tumor remains uncertain. Various cell lineages such as vascular, glial, neural, fibrohistiocytic, and smooth muscle/myofibroblastic have been proposed for the so-called stromal cells, which are thought to represent the neoplastic component of these lesions. We report on 5 cases of hemangioblastoma arising in extraneural tissues. Two of the tumors were located in the presacral region, and one each in the maxilla, kidney, and adrenal glands. All 5 cases were morphologically indistinguishable from central nervous system hemangioblastoma. The existence of these cases suggests that the "stromal" cells of hemangioblastoma can demonstrate a variety of mature specific lineages, such as smooth muscle/myofibroblastic, or neuroendocrine, depending on the location and possibly the microenvironment.