Clinical and histological study of follicular helper T-cell lymphomas with indolent evolution

INTRODUCTION

Follicular helper T-cell lymphomas (TFHL) have an aggressive course with a poor outcome. European and US guidelines recommend anthracycline-based chemotherapy as a first-line treatment, but the 5-year overall survival rate is still approximately 30%. We describe here the features of a cohort of TFHL patients who experienced prolonged survival despite the absence of specific treatment or the initiation of steroid-based therapy.

PATIENTS AND METHODS

In our study, we describe 15 adult patients who suffered from TFHL and had not received intensive chemotherapy at diagnosis for any reason. Biopsies of these cases were centrally reviewed, and the mutational pattern was determined using next-generation sequencing.

RESULTS

These 15 patients had the classic clinical, biological and pathological features of TFHL, angioimmunoblastic-type. TET2 mutations were found in 83% of patients; RHOA G17V, IDH2 R172 and DNMT3A mutations were found in 67%, 42% and 33% of the patients, respectively. Among the 15 patients, 8 did not receive any treatment, and 7 received steroid-based treatment. Ten patients had progression (5 in each group). Four patients died (3 of them from the progression of their lymphoma). The median follow-up in our cohort was 53 months. The 5-year OS was 66%, 100% for untreated patients and 29% for the others. In those 2 groups, the median time to treatment initiation was 22 months from diagnosis.

CONCLUSION

We described a series of 15 well-characterized TFHL patients with an indolent outcome, suggesting that a watch-and-wait approach can be proposed in selected patients. Identifying factors predicting such evolution is warranted.

Peritoneal or mesenteric tumours revealing histiocytosis

Objective

Peritoneal or mesenteric tumours may correspond to several tumour types or tumour-like conditions, some of them being represented by histiocytosis. This rare condition often poses diagnostic difficulties that can lead to important time delay in targeted therapies. Our aim was to describe main features of histiocytoses with mesenteric localisation that can improve the diagnostic process.

Design

We performed a retrospective study on 22 patients, whose peritoneal/mesenteric biopsies were infiltrated by histiocytes.

Results

Abdominal pain was the revealing symptom in 10 cases, and 19 patients underwent surgical biopsies. The diagnosis of histiocytosis was proposed by initial pathologists in 41% of patients. The other initial diagnoses were inflammation (n=7), sclerosing mesenteritis (n=4) and liposarcoma (n=1). The CD163/CD68+CD1a- histiocytes infiltrated subserosa and/or deeper adipose tissues in 16 and 14 cases, respectively. A BRAF^V600E mutation was detected within the biopsies in 11 cases, and two others were MAP2K1 mutated. The final diagnosis was histiocytosis in 18 patients, 15 of whom had Erdheim-Chester disease. The median diagnostic delay of histiocytosis was 9 months. Patients treated with BRAF or MEK inhibitors showed a partial response or a stable disease. One patient died soon after surgery, and five died by the progression of the disease.

Conclusion

Diagnosis of masses arising in the mesentery should be carefully explored as one of the possibilities in histiocytosis. This diagnosis is frequently missed on mesenteric biopsies. Molecular biology for detecting the mutations in BRAF or in genes of the MAP kinase pathway is a critical diagnostic tool.

Anti-apoptotic role and clinical relevance of neurotrophins in diffuse large B-cell lymphomas

Background:

Diffuse large B-cell lymphoma (DLBCL) is a fatal malignancy that needs to identify new targets for additional therapeutic options. This study aimed to clarify the clinical and biological significance of endogenous neurotrophin (nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF)) in DLBCL biopsy samples and cell lines.

Methods:

We analysed expression of NGF, BDNF, and their receptors (Trk, p75^NTR) in 51 biopsies and cell lines by immunohistochemistry, immunofluorescence, and western blotting. To investigate the biological role of BDNF/TrkB/p75^NTR axis, effects of neurotrophin signalling inhibition were determined on tumour cell survival and vascular endothelial growth factor (VEGF) secretion. The pharmacological pan-Trk inhibitor K252a was used for in vitro and in vivo studies.

Results:

A BDNF/TrkB axis was expressed in all biopsies, which was independent of the germinal centre B-cell (GCB)/non-GCB profile. p75^NTR, TrkB, and BDNF tumour scores were significantly correlated and high NGF expression was significantly associated with MUM1/IRF4, and the non-GCB subtype. Diffuse large B-cell lymphoma cell lines co-expressed neurotrophins and their receptors. The full-length TrkB receptor was found in all cell lines, which was also phosphorylated at Tyr-817. p75^NTR was associated to Trk and not to its cell death co-receptor sortilin. In vitro, inhibition of neurotrophin signalling induced cell apoptosis. K252a caused cell apoptosis, decreased VEGF secretion, and potentiated rituximab effect, notably in less rituximab-sensitive cells. In vivo, K252a significantly reduced tumour growth and potentiated the effects of rituximab in a GCB-DLBCL xenograft model.

Conclusions:

This work argues for a pro-survival role of endogenous neurotrophins in DLBCLs and inhibition of Trk signalling might be a potential treatment strategy for rituximab resistant subgroups.

[Hypoglycaemic coma revealing a malignant recurrence during Doege-Potter syndrome]

INTRODUCTION

The Doege-Potter syndrome is a rare paraneoplastic syndrome, first described by Doege and Potter in 1930, that usually involves solid fibrous pleural tumours. Hypoglycaemia is a rare complication of these tumours, due to secretion of insulin-like growth factors, and it can be the presenting symptom. The incidence of malignancy is low, about 12-15 %.

CASE REPORT

An 81-year-old Caucasian man, operated on 20 years previously for a benign pleural fibroma, presented with several episodes of loss of consciousness due to profound hypoglycaemia and a history of increasing dyspnea. The chest X-ray revealed an intrathoracic mass. Following excision histological examination confirmed recurrence with malignant transformation to a high-grade sarcoma.

CONCLUSION

The Doege-Potter syndrome is a rare condition but it should be suspected in episodes of hypoglycaemia associated with a history of dyspnea. These patients should be followed up postoperatively because of the risk of tumour recurrence.

[Two cases reports of pancreatic endocrine microadenoma incidentally found]

A 59-year-old male, was admitted to our hospital for a tumor of the pancreatic tail. Serum CEA and CA 19-9 levels were normal. Splenopancreasectomy found a desmoid tumour. A 69-year-old male was referred to our institution for chronic anemia and inflammatory syndrome with splenomegaly. Splenectomy showed an important splenic congestion and siderosis. Both patients had a type 2 diabetes mellitus. Furthermore, histological examination revealed pancreatic endocrine microadenomas. The two patients' postoperative course was unremarkable. Eleven and 24 months respectively after the diagnosis, the patients are alive and well, with no tumor recurrence.

A MEN1 syndrome with a paraganglioma

Germline mutations of the MEN1 gene cause multiple endocrine neoplasia type 1 (MEN1), an autosomal dominant disorder characterized by tumors of the parathyroids, the pancreas, and the anterior pituitary. Paraganglioma (PGL) is a rare endocrine tumor, which can be sporadic or genetically determined. To date, PGL has never been reported as a feature of MEN1.We report here a patient presenting three features of MEN1 syndrome (hyperparathyroidism, pancreatic neuroendocrine tumor, and adrenocortical adenoma) associated with PGL. Genetic analysis of MEN1 gene revealed a new missense mutation in exon 5 (AGGAAG), causing the substitution of arginine by lysine at codon 275. Screening for other genetic disorders (SDHx, TMEM127, MAX, CDKN1B) causing PGL was negative. Immunohistochemical analyses showed normal levels of succinate dehydrogenase (SDH)A and SDHB in the PGL. The proband's sister, bearing the mutation, had primary hyperparathyroidism. It was the first typical MEN1 syndrome reported with an extra-adrenal PGL.

A Report of a Desmoplastic Ganglioglioma in a 12-year-old Girl with Review of the Literature

Desmoplastic infantile ganglioglioma is a supratentorial tumor that typically occurs in infants below the age of 24 months. Rare tumors with the same radiological and histological characteristics have been described in older subjects. We report a case of desmoplastic ganglioglioma in a 12-year-old girl with a 13 years follow-up. The patient presented with an inaugural generalized seizure. CT scan demonstrated a large superficial parieto-occipital mass, attached to the dura with solid and cystic components. Surgical resection was macroscopically complete. No adjuvant treatment was given. Thirteen years after surgery, the patient is symptom free. Histological examination revealed a pleomorphic tumor involving the meningeal space and the cortex. Meningeal portion was made of neoplastic astrocytes enmeshed in a dense network of connective tissue. The cortical component showed abnormal neurons, tumoral astrocytes and small foci of poorly differentiated cells with rare mitoses. Our observation and the seven others found in the literature indicate that desmoplastic gangliogliomas can occur in children and even in young adults. Despite some worrisome radiological and histological features, these tumors should not be misdiagnosed as malignant glioma. Like infantile cases, non-infantile desmoplastic gangliogliomas seem to have a favorable prognosis without additional therapy, if a total surgical resection can be performed.

[Onychomatricoma, a rare lesion of the nail]

Onychomatricoma is a rare fibroepithelial lesion of the nail matrix with peculiar clinical and histological features. Clinically, it is characterized by a longitudinal band of yellow thickening of the nail plate with transverse overcurvature and splinter hemorrhages. Nail avulsion exposes a villous tumor of the matrix with filamentous digitations extending into multiple holes of the nail plate. Histologically, a thick keratogenous zone forms a thickened nail plate. The lesion in its proximal portion is characterized by deep epithelial invaginations and by a stroma organized in two layers. The distal zone corresponds to multiple fibroepithelial projections extending into the nail plate. The diagnosis can be difficult in the presence of misleading clinical features or when the specimen is incomplete or examined with an improper orientation. Surgical resection is the recommended treatment.

[Isolated neurosarcoidosis without systemic signs]

Sarcoidosis is a multisystemic disease which involves the nervous system in 5 to 15 p.cent. Neurosarcoidosis without signs of systemic disease is rare and may be difficult to diagnose. We report a case of a 61 year-old patient with a pseudotumoral neurosarcoidosis and along evolution of 25 years without systemic signs. In such cases, histological analysis is rewarding.