Diagnosis of Mesothelioma

Mesothelioma is a rare neoplasm that arises from mesothelial cells lining body cavities including the pleura, pericardium, peritoneum, and tunica vaginalis. Most malignant mesotheliomas occur in the chest and are frequently associated with a history of asbestos exposure. The diagnosis of malignant mesothelioma is challenging and fraught with pitfalls, particularly in small biopsies. This article highlights what the pathologist needs to know regarding the clinical and radiographic presentation of mesothelioma, histologic features including subtypes and variants, and recent advances in immunohistochemical markers and molecular testing.     

Primary intracranial T cell type malignant lymphoma: a case report

Primary intracranial T cell type malignant lymphoma is extremely rare. Only 8 cases are reported in the literature so far. In this paper, a case with this type of malignant lymphoma is reported. A 41-year-old man was admitted because of abnormal behavior. Enhanced CT scan demonstrated high density mass and perifocal low-density area in the right frontal lobe, the right basal ganglia and the periventricular region. Specimen biopsied from right frontal lobe was submitted for histological examination. An immunohistochemical technique using monoclonal surface markers confirmed reactivity for LCA, MT-1, OKT-4 and OKT-8, while there was no reactivity for MB-1 and OKB-2. Pathological diagnosis was diffuse medium T cell type malignant lymphoma. Postoperatively, after 60 Gy irradiation, the tumor disappeared. There is no difference on CT findings between B cell type and T cell type malignant lymphoma.     

Increased expression of tenascin in pheochromocytomas correlates with malignancy.

Tenascin is a significant extracellular matrix glycoprotein, which is upregulated in various neoplasias and pathologic processes. Pheochromocytomas are rare tumors of the sympathoadrenal system, whose malignancy is almost impossible to predict. There are no histologic or chemical markers available that would define the malignant behavior of these tumors, except the discovery of metastases. In our search for new markers, we investigated the immunohistochemical expression of tenascin in a large number of pheochromocytomas and paragangliomas. Seven tumors were metastasized and were thus considered malignant. Normal adrenal medulla was tenascin negative. A striking difference was seen between malignant and benign pheochromocytomas. All malignant pheochromocytomas expressed stromal tenascin strongly or moderately, whereas most benign pheochromocytomas (28 of 37, 70%) showed no or only weak immunopositivity. The staining was strong or moderate also in 13 of 28 (46%) of the tumors that showed histologically suspicious features, here called borderline tumors. Paragangliomas showed a more heterogeneous staining pattern, and no significant difference was found between benign and malignant paragangliomas. To our knowledge, this is the first study to demonstrate the expression of tenascin in pheochromocytomas and particularly the enhanced expression in malignant pheochromocytomas. We therefore suggest that tenascin may be associated with the malignant transformation and metastasis of pheochromocytomas. It is also a potential marker predicting more aggressive behavior in pheochromocytomas.     

Mucinous cystadenocarcinoma of the appendix. A rare tumor of the right iliac fossa

An observation of a mucinous cystadenocarcinoma of the appendix, in the tumor form, revealed by a painful syndrome of the right iliac fossa in a 62-year man is reported. It is a rare malignant tumor as less than 0.5% of the appendicectomy parts present a malignant mucosecreting tumor. In our observation, the diagnosis was allowed by pre-operation imaging. An increase of the serous amount in the tumor markers (carcinoembryonic antigen) (CEA) and CA 19-9 was found before the intervention and the immunodetections performed on the operation part were positive for CEA and CA 19-9. The serous amounts of these markers were normalized after operation. To the author's knowledge, the interest of dosing the serous tumor markers in the observation of such a type of tumor is not mentioned in the literature. The recurrences are frequent and sometimes late even when the initial excision has been macroscopically satisfactory. A new increase of the serous amount of the markers could allow for an earlier detection of a recurrence during the patient follow-up. At present, the prognosis of these malignant forms remains very poor as the 5-year survival does not exceed 25%.     

Primary mediastinal malignant germ cell neoplasms: imaging features

Mature teratomas are the most frequent primary mediastinal GCN. These are spherical multilocular cystic masses with thin, soft tissue septa and frequent internal fat attenuation. Primary mediastinal malignant GCNs are rare and should be included in the differential diagnosis of anterior mediastinal masses in young adult males. Seminomas are typically homogeneous masses indistinguishable from lymphomas. Radiologically nonseminomatous malignant germ cell neoplasms are large, locally invasive heterogeneous masses with central low-attenuation and frond-like peripheral soft tissue. Gonadal primary malignancy and intervening abdominal lymph node involvement should be excluded. Tumor markers play a crucial role in the initial evaluation of anterior mediastinal masses in these patients and in evaluating response to therapy and possible recurrence. Follow-up imaging is helpful in detection and characterization of residual neoplasm.     

Testicular epidermoid cyst: uncommon lesion of difficult preoperative diagnosis

Intratesticular epidermoid cysts are rare tumours that constitute one percent of all testicular masses. They are bening lesions that make differential diagnosis from malignant testicular tumours difficult. The absence of serum markers elevation and ultrasound imaging could support these lesions being bening epidermoid cysts, and in that case, conservative surgery is adequate. We present the case of a 22 years old patient who complains of a left testicular mass. In this case ultrasound diagnosis was non-specific and a left radical inguinal orchiectomy was performed.     

Case report of a littoral cell angioma of the spleen and accessory spleens: A benign vascular tumour

IntroductionLittoral- cell angioma (LCA) is a rare benign vascular tumour of the spleen. There have been less then 80 cases reported in the literature.Recent reports have described it to be a malignant lesion with congenital and immunologic associations. We report a case of LCA of the spleen.Presentation of caseA 52 -year-old male patient was admitted to hospital with a three month duration of intermittent upper abdominal pain and nausea. Imaging studies, including computer tomography (CT) and magnetic resonance imaging (MRI), showed multiple lesions in the spleen as well as in the accessory spleens.An open splenectomy was performed and his post-operative recovery was uneventful.DiscussionLittoral cell angioma of the spleen is a benign vascular tumour that has been infrequently reported in the English literature. While it does have malignant potential, the vast majority are benign. Diagnosis depends on the expression of endothelial markers like CD31 and histiocytic markers like CD68.Malignant potential is enhanced by the presence of splenomegaly as well.ConclusionThis rare condition is made even more rare by the presence of the tumour in the two accessory spleens as well.     

Pleomorphic adenoma of the submandibular gland

Pleomorphic adenomas of the submandibular glands are exceedingly rare tumors in the pediatric practice. Patients usually present with a painless and mobile mass without any other associated symptoms. Radiologic studies are usually unable to differentiate benign from malignant tumors in most cases. Recurrences are rare with complete en bloc excision of the tumor and the submandibular gland. Except for the rare cases of malignant transformation, the prognosis is excellent.     

Primary malignant melanoma of the right colon

The small and large intestines are the most common sites for metastases from cutaneous malignant melanoma. However, primary melanomas in these sites are exceedingly rare. There are several case reports of patients with primary melanoma of the small bowel, but finding of a solitary primary melanoma in the colon is exceedingly rare. We describe a patient that was operated on for bowel obstruction due to colonic intussusception resulting from a right colonic tumor. Histopathological examination confirmed a diagnosis of malignant melanoma. A thorough postoperative investigation did not reveal a primary lesion in any other site. Two years after surgery, there was no evidence for recurrent disease. The treatment and prognosis of metastatic and primary melanoma of the gastrointestinal tract is discussed as well as the embryonic base for development of primary malignant melanoma of the intestine. Primary malignant melanoma of the intestine is an extremely rare lesion that may arise in the large bowel as well. It must be differentiated from other intestinal tumors and mandates a thorough investigation to rule out the possibility of being a metastasis from another more common primary site.     

Malignant perivascular epithelioid cell tumor in children: description of a case and review of the literature

Perivascular epithelioid cell tumors (PEComas) include different morphological entities originating from perivascular epithelioid cells. Their clinical behavior is not predictable, and there are no strict histologic criteria for malignancy, although larger tumors with infiltrative growth, hypercellularity, cellular atypia, atypical mitoses, and necrosis generally have a malignant course. Pediatric PEComas are rare, with less than 40 cases reported, mostly in children older than 5 years. We describe a case of malignant PEComa of the ligamentum teres in a 2-year-old girl, characterized by the occurrence of local relapse after primary treatment with chemotherapy and surgery and poor response to imatinib mesilate and temsirolimus used after further analyses confirmed p70S6K expression involved in the mTOR pathway. The girl was eventually treated with a debulking surgical procedure and is now alive with disease 6 years after diagnosis. Literature data of children affected by PEComas were also analyzed, trying to identify pathologic characteristics that could predict their course and therapeutic options. Histologically, they may be differentiated in 3 prognostic categories: (1) benign, lacking unfavorable morphological markers; (2) with uncertain malignant potential, carrying 1 unfavorable marker; and (3) malignant, with at least 2 unfavorable markers. In the literature, 9% of cases occurred as a second malignancy probably because of genomic instability related to treatment. Their different biology and the potential value of targeted therapies remain to be explored. The indolent evolution in our patient was similar to that reported in some other cases in the literature. In terms of treatment, the present case suggests a minor response to temsirolimus compared with the adult population.     

Große solitäre fibröse Tumoren der Pleura als Zufallsbefund

The solitary fibrous tumor (SFT) is a very rare and usually benign neoplasm. This tumor is mostly located in the thoracic cavity, but it has also been reported in numerous sites including liver, skin, and meninges. Due to its rarity diagnosis is often difficult. Accordingly, histopathological differentiation is of major importance. Solitary fibrous tumors consistently express CD 34 and react negatively to epithelial markers. This absence of expression of epithelial markers, especially cytokeratin, is also useful to distinguish these rare entities from sarcomatous mesotheliomas. The treatment of choice for solitary fibrous tumors is extensive surgical resection. Up to now there is no evidence that radiation and chemotherapy are effective. The local recurrence or onset of metastases depends on histologic parameters. In cases of benign classification (60-80%), the recurrence rate was only 2% after surgical excision. One-half of the patients with malignant tumors can be cured; the rest develop recurrences and metastases more often. Especially in those cases, emphasis should be placed on continual follow-up examination. We report two cases of a 65- and a 75-year-old male patient with huge intrathoracic solitary fibrous subpleural tumors, discovered incidentally on routine chest X-ray.     

Stromal tumour of the rectum: laparoscopic approach of a rare localization of GIST

The authors present the case of a 60 year-old man known for a rectal polyp which was diagnosed in 1994 and since then followed-up by means of a colonoscopy associated with periodic biopsies. Recently, the results of a biopsy revealed positive markers for the diagnosis of Gastro-Intestinal Stromal Tumor (GIST). Despite the absence of malignant criteria, an anterior resection of the rectum was performed by laparoscopy and the patient rapidly recovered. Epidemiology, diagnosis and management of this rare location of GIST's are discussed.     

Stromal Tumour of the Rectum: Laparoscopic Approach of a Rare Localization of GIST

The authors present the case of a 60 year-old man known for a rectal polyp which was diagnosed in 1994 and since then followed-up by means of a colonoscopy associated with periodic biopsies. Recently, the results of a biopsy revealed positive markers for the diagnosis of Gastro-Intestinal Stromal Tumor (GIST). Despite the absence of malignant criteria, an anterior resection of the rectum was performed by laparoscopy and the patient rapidly recovered. Epidemiology, diagnosis and management of this rare location of GIST’s are discussed.     

Paediatric Intra-abdominal Inflammatory Myofibroblastic Tumour

Inflammatory myofibroblastic tumour is a rare solid tumour mimicking malignancy with locally aggressive growth and recurrence even after complete resection. We report the case of a 10-year-old girl with an intra-abdominal inflammatory myofibroblastic tumour. This clinical and pathological entity should be differentiated from other malignant sarcomatous lesions when encountered intraoperatively. It is almost impossible to differentiate inflammatory myofibroblastic tumour from other malignancies preoperatively; the diagnosis is often confirmed by careful microscopic examination or immunohistochemical markers after surgical resection. Total excision of the tumour with life-time follow-up is needed because of the risk of recurrence.     

Giant epidermoid cyst of the spleen with carbohydrate and cancer antigen production managed laparoscopically

True cysts of the spleen are rare; in a few cases, high serum levels of carbohydrate and cancer antigen have been reported. In such instances, cyst resection or splenectomy is indicated to rule out malignant lesions and to remove the cancer antigen producing epithelium. We report the case of a young woman with a symptomatic giant epidermoid cyst of the spleen. Due to the secreting epithelium lining the cyst, serum levels of CA 19-9 and CA 125 were elevated. Laparoscopic splenectomy achieved symptoms relief and and long-term normalization of serum tumor markers.     

Multicystic malignant mesothelioma of the tunica vaginalis with an unusually indolent clinical course

We report an extremely rare case of a multicystic malignant mesothelioma in the tunica vaginalis with an unusually indolent clinical course. A 48-year-old man presented with a one-month history of painless swelling of right scrotal contents. Ultrasonography and computed tomography (CT) revealed a multicystic mass in the right scrotal sac with evidence of neither distant nor lymph node metastases. The testicular tumor markers were within the normal limits. Inguinal orchiectomy was performed under the suspicion of a malignant tumor. The cystic tumor consisted of fibrocellular, microcystic and adenomatoid elements microscopically was diagnosed biphasic malignant mesothelioma of tunica vaginalis but no invasion into the testis, epididymis and also scrotum. The patient has been disease-free for 72 months and is being followed on an outpatient basis with no further adjuvant therapy.     

Pecoma of the lung: a benign tumor with extensive 18F-2-deoxy-D-glucose uptake

A case of lung pecoma (i.e. tumors showing perivascular epithelioid cell differentiation) with extensive 18F-2-deoxy-D-glucose (FDG) uptake in PET/CT study is reported. Pecomas of the lung--which include the better known clear cell 'sugar' tumor--are a subset of extremely rare lung tumors which usually react positively to both melanocytic and smooth muscle markers. Although widely presumed as benign in computed tomography (CT) and positron emission tomography (PET)/CT studies they depict as malignant, thus complicating the preoperative diagnosis. A subset of pecomas could conceal a malignant potential.     

Malignant transformation of a benign cutaneous mixed tumour

Whilst benign cutaneous mixed tumour is common, malignant cutaneous mixed tumour is rare. There are only eleven accepted cases of the malignant counterpart in the literature. In none was there residual benign tumour tissue present to suggest that they arose from malignant transformation of the benign tumour. We report a very rare case of a malignant transformation of a benign cutaneous mixed tumour in an eighty-four year old female. Other unusual features in this case included considerable involvement of bone in the primary lesion and the histological picture of extreme pleomorphism and active mitoses, not seen in other reported cases of the malignant tumour.