Pulmonary sclerosing hemangioma associated with familial adenomatous polyposis

Molecular Genetic Landscape of Sclerosing Pneumocytomas

OBJECTIVES

Sclerosing pneumocytomas are rare pulmonary neoplasms that are typically benign. However, rare patients experience progressive disease, and therapy targeting specific genetic underpinnings could be an attractive therapeutic option. Recent studies have found recurrent AKT 1 mutations in sclerosing pneumocytoma, but little is known about whether oncogenic fusion genes may also be present.

METHODS

To better understand the genetic background, 10 sclerosing pneumocytomas were subjected to next-generation sequencing cancer mutation panel testing (n = 9) and/or RNA sequencing (n = 3). The patients were all women (average age, 47 years; range, 17-74 years).

RESULTS

Eight patients had solitary sclerosing pneumocytomas, while one had two tumors, and one had many bilateral tumors. Recurrent mutations were noted in genes involved in the mTOR pathway, including AKT1, PIK3R1, and PTEN. AKT1 alterations were particularly common, present in 78%. No recurrent genetic fusions were identified. The patient in our study with multiple bilateral lesions was treated with the mammalian target of rapamycin (mTOR) inhibitor everolimus, with no objective radiographic evidence of treatment response after 4 months.

CONCLUSIONS

Our data further support that abnormal activation of the mTOR pathway is a consistent genetic event in sclerosing pneumocytoma. This warrants further exploration to determine if mTOR pathway inhibitors may be effective in patients with metastatic or recurrent disease.

CTNNB1 (β-Catenin)-altered Neoplasia: A Review Focusing on Soft Tissue Neoplasms and Parenchymal Lesions of Uncertain Histogenesis

β-catenin (CTNNB1) is a key regulatory molecule of the Wnt signaling pathway, which is important for tissue homeostasis and regulation of cell proliferation, differentiation, and function. Abnormal stabilization and nuclear accumulation of β-catenin as a consequence of missense mutations or alternative molecular mechanisms occurs at a high frequency in a variety of epithelial cancers. In mesenchymal neoplasia, the role of β-catenin has been traditionally considered limited to desmoid-type fibromatosis. However, the spectrum of β-catenin-driven (β-catenin-altered) neoplasia of mesenchymal origin has been steadily widening to include, in addition to desmoid tumors, a variety of benign and intermediate-biology neoplasms of soft tissue (intranodal palisaded myofibroblastoma), head and neck (juvenile nasopharyngeal angiofibroma and sinonasal hemangiopericytoma/glomangiopericytoma), and ovarian (microcystic stromal tumor) origin. In addition, several old and newly reported distinctive site-specific β-catenin-driven parenchymal neoplasms of uncertain histogenesis have been well characterized in recent studies, including solid-pseudopapillary neoplasm of the pancreas and its recently described ovarian counterpart, sclerosing hemangioma of lung and calcifying nested stromal-epithelial tumor of the liver. This review addresses the most relevant pathobiological and differential diagnostic aspects of β-catenin-altered neoplasms with emphasis on site-specific histologic and biological variations. In addition, the morphologic overlap and analogy as well as distinctness between these uncommon tumors will be presented and discussed. Furthermore, a note is made on association of some of these lesions with hereditary tumor syndromes, in particular with the familial adenomatous polyposis coli.

In pulmonary sclerosing hemangioma expression of β-catenin, Axin, and C-myc differs between the two cell types

Previous studies have shown that pulmonary sclerosing hemangioma is a tumor derived from primitive respiratory epithelium, but its character and the differentiation status of the two cell types (polygonal and cuboidal) composing the lesion are still controversial. We hypothesize that the polygonal cells are immature compared with cuboidal cells and have higher proliferative activity. To further study this question, we examined the expression of β-catenin, Axin, and C-myc by immunostaining in 45 primary sclerosing hemangioma (PSH) specimens. The two cell types were captured by laser capture microdissection from 28 PSH specimens, and total RNA was extracted. Messenger RNA (mRNA) expression of Axin and C-myc was examined by reverse transcription polymerase chain reaction (RT-PCR). By immunostaining, β-catenin was predominantly strongly expressed on the cell membrane of cuboidal cells, while in polygonal cells, β-catenin was predominantly expressed in the cytoplasm and significantly decreased on cell membranes. Axin was expressed in cuboidal cells in 93 % of our 45 cases, but only expressed in 18 % of these in polygonal cells. C-myc expression in polygonal cells was significantly stronger than in cuboidal cells (P < 0.05). RT-PCR showed that the expression level of Axin mRNA in cuboidal cells was significantly higher than in polygonal cells (P < 0.05), and expression level of C-myc mRNA in polygonal cells was significantly higher than in cuboidal cells (P < 0.05).The two PHS cell types have distinct expression of β-catenin, Axin, and C-myc, suggesting that their differentiation status may be different. The higher expression of C-myc in polygonal cells suggests that these cells might have higher proliferative activity.

Pulmonary sclerosing hemangioma in a 21-year-old male with metastatic hereditary non-polyposis colorectal cancer: report of a case

Background

Pulmonary sclerosing hemangioma (SH) is a rare tumor of the lung predominantly affecting Asian women in their fifth decade of life. SH is thought to evolve from primitive respiratory epithelium and mostly shows benign biological behavior; however, cases of lymph node metastases, local recurrence and multiple lesions have been described.

Case Presentation

We report the case of a 21-year-old Caucasian male with a history of locally advanced and metastatic rectal carcinoma (UICC IV; pT4, pN1, M1(hep)) that was eventually identified as having hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome). After neoadjuvant chemotherapy followed by low anterior resection, adjuvant chemotherapy and metachronous partial hepatectomy, he was admitted for treatment of newly diagnosed bilateral pulmonary metastases. Thoracic computed tomography showed a homogenous, sharply marked nodule in the left lower lobe. We decided in favor of atypical resection followed by systematic lymphadenectomy. Histopathological analysis revealed the diagnosis of SH.

Conclusions

Cases have been published with familial adenomatous polyposis (FAP) and simultaneous SH. FAP, Gardner syndrome and Li-Fraumeni syndrome, however, had been ruled out in the present case. To the best of our knowledge, this is the first report describing SH associated with Lynch syndrome.

Pulmonary sclerosing hemangioma with atypical radiologic findings

Sclerosing hemangioma of the lung is an uncommon benign tumour that usually presents as an asymptomatic solitary nodule and affects middle age women. Because there are few findings on radiologic studies that are characteristic of sclerosing hemangioma, it is difficult to diagnose on the basis of imaging and biopsy remains the definitive diagnostic test. We report a case of pulmonary sclerosing hemangioma with extremely unexpected imaging findings and review the literature.

Pulmonary sclerosing hemangioma detected by fluorodeoxyglucose positron emission tomography in familial adenomatous polyposis: report of a case

We present a 53-year-old female suffering from familial adenomatous polyposis, who was found to have a positive nodus, lateral to the hilus of the left lung, on routine FDG-PET scan. This lesion was found to be a sclerosing hemangioma. We found an aberrant beta-catenin expression on immunohistochemical staining, suggesting that sclerosing hemangioma and familial adenomatous polyposis share the same pathophysiology. It is important to be aware of the association of familial adenomatous polyposis and sclerosing hemangioma.

[Pulmonary sclerosing hemangioma in a patient with Cowden syndrome]

We describe the case of an 18-year-old female with Cowden syndrome in whom a simple x-ray detected a solitary pulmonary nodule that was identified as a sclerosing hemangioma. Pulmonary sclerosing hemangioma is an unusual lung neoplasm which typically presents as a solitary peripheral nodule in asymptomatic women. Although the histology of this entity is well defined, its origin and treatment is debated. One of the main diagnostic problems is to histologically differentiate a pulmonary sclerosing hemangioma from a papillary lung carcinoma.

Ability of FDG-PET to detect all cancers in patients with familial adenomatous polyposis, and impact on clinical management

PURPOSE

Familial adenomatous polyposis (FAP) is characterised by colonic and duodenal adenomatous polyps that carry a risk of malignant transformation. Malignant degeneration of duodenal adenomas is difficult to detect. We speculated that 2-((18)F)-fluoro-2-deoxy-D: -glucose positron emission tomography (FDG-PET) might be able to detect early duodenal cancer in FAP. Accordingly, we investigated the role of FDG-PET in the management of FAP patients.

METHODS

FDG-PET was performed in 24 FAP patients. Eight had advanced duodenal adenomas (Spigelman IV), including two patients with duodenal cancer. Scans were defined as positive on the basis of focal FDG accumulation.

RESULTS

Pathological FDG accumulation was absent in 19 of 24 patients. All six patients with Spigelman IV duodenal adenomas (without cancer) were negative; two of these underwent a duodenectomy and pathological examination did not reveal duodenal cancer. In five patients, FDG-PET revealed significant uptake, in the duodenum (2), lower abdomen (1), lung (1) and multiple sites in the abdomen (1). These hot spots correlated with duodenal cancer (2), abdominal metastasis (1) and sclerosing haemangioma of the lung (1). We failed to make a histopathological diagnosis in the single patient with multiple intra-abdominal sites of FDG uptake. None of the patients from the FDG-PET-negative group developed cancer during follow-up (mean 2.8 years).

CONCLUSION

FDG-PET detected all the cancers present, and none of the patients with negative FDG-PET developed cancer. This suggests that positive FDG-PET in FAP patients should lead to further examinations to rule out cancer. In patients with negative FDG-PET a more conservative approach seems justified.