Hepatic perivascular epithelioid cell tumors: Benign, malignant, and uncertain malignant potential

In 2013, the World Health Organization defined perivascular epithelioid cell tumor (PEComa) as "a mesenchymal tumor which shows a local association with vessel walls and usually expresses melanocyte and smooth muscle markers." This generic definition seems to better fit the PEComa family, which includes angiomyolipoma, clear cell sugar tumor of the lung, lymphangioleiomyomatosis, and a group of histologically and immunophenotypically similar tumors that include primary extrapulmonary sugar tumor and clear cell myomelanocytic tumor. Clear cell tumors with this immunophenotypic pattern have also had their malignant variants described. When localizing to the liver, preoperative radiological diagnosis has proven to be very difficult, and most patients have been diagnosed with hepatocellular carcinoma, focal nodular hyperplasia, hemangioma, or hepatic adenoma based on imaging findings. Examples of a malignant variant of the liver have been described. Finally, reports of malignant variants of these lesions have increased in recent years. Therefore, we support the use of the Folpe criteria, which in 2005 established the criteria for categorizing a PEComa as benign, malignant, or of uncertain malignant potential. Although they are not considered ideal, they currently seem to be the best approach and could be used for the categorization of liver tumors.

Third International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

The heterogeneous group of B3 lesions in the breast harbors lesions with different malignant potential and progression risk. As several studies about B3 lesions have been published since the last Consensus in 2018, the 3rd International Consensus Conference discussed the six most relevant B3 lesions (atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), radial scar (RS), papillary lesions (PL) without atypia, and phyllodes tumors (PT)) and made recommendations for diagnostic and therapeutic approaches. Following a presentation of current data of each B3 lesion, the international and interdisciplinary panel of 33 specialists and key opinion leaders voted on the recommendations for further management after core-needle biopsy (CNB) and vacuum-assisted biopsy (VAB). In case of B3 lesion diagnosis on CNB, OE was recommended in ADH and PT, whereas in the other B3 lesions, vacuum-assisted excision was considered an equivalent alternative to OE. In ADH, most panelists (76%) recommended an open excision (OE) after diagnosis on VAB, whereas observation after a complete VAB-removal on imaging was accepted by 34%. In LN, the majority of the panel (90%) preferred observation following complete VAB-removal. Results were similar in RS (82%), PL (100%), and FEA (100%). In benign PT, a slim majority (55%) also recommended an observation after a complete VAB-removal. VAB with subsequent active surveillance can replace an open surgical intervention for most B3 lesions (RS, FEA, PL, PT, and LN). Compared to previous recommendations, there is an increasing trend to a de-escalating strategy in classical LN. Due to the higher risk of upgrade into malignancy, OE remains the preferred approach after the diagnosis of ADH.

Recurrent Prostatic Stromal Tumor of Uncertain Malignant Potential Combined with Concurrent Prostatic Adenocarcinoma: An Unusual Case

Prostatic stromal tumor of uncertain malignant potential (STUMP), characterized by an atypical, unique stromal proliferation of the prostate, is often difficult to be differentiated from other nonepithelial neoplastic lesions. We present a unique case of recurrent STUMP after transurethral resection of the prostate (TURP) with concurrent prostatic adenocarcinoma. Patients diagnosed with prostatic STUMP should be followed up closely, for it may recur and invade adjacent organs after TURP shortly. Concurrent prostatic adenocarcinoma can be found in STUMP patients, and there may be some potential mechanisms which promote the simultaneous occurrence of the 2 tumors.

Breast lesions excised via vacuum-assisted system: could we get any clues for B3 lesions before excision biopsy?

Background

The purpose of this study was to determine the validity of the ultrasound features as well as patient characteristics assigned to B3 (uncertain malignant potential) breast lesions before vacuum-assisted excision biopsy (VAEB).

Methods

This study population consisted of 2245 women with breast-nodular abnormalities, which were conducted ultrasound-guided VAEB (US-VAEB). Patient’s clinical and anamnestic data and lesion-related ultrasonic feature variables of B3 captured before US-VAEB were compared with those of benign or malignant cases, using histopathological results as a benchmark.

Results

The proportions of benign, B3 and malignant breast lesions diagnosed post-US-VAEB were 88.5, 8.2 and 3.4% respectively. B3 high frequent occurred in BI-RADS-US grade 3 (7.7%), grade 4a (11.0%) and grade 4b (9.1%). The overall malignancy underestimation rate of B3 was 4.4% (8/183). Malignant lesions were found mostly in the range of BI-RADS grade 4b (27.3%), grade 4c (33.3%) and grade 5 (100%). Multivariate binary logistic regression analyses (B3 vs benign) showed that non-menopausal patients (95% CI 1.628–8.616, P = 0.002), single (95% CI 1.370–2.650, P = 0.000) or vascularity (95% CI 1.745–4.150, P = 0.000) nodules in ultrasonic features were significant risk factors for B3 occurrences. In addition, patients elder than 50 years (95% CI 3.178–19.816, P = 0.000), unclear margin (95% CI 3.571–14.119, P = 0.000) or suspicious calcification (95% CI 4.010–30.733, P = 0.000) lesions were significantly associated with higher risks of malignant potentials for B3 cases (malignant vs B3).

Conclusion

The results of this study indicate that ultrasound findings and patients’ characteristics might provide valuable information for distinguishing B3 lesions from benign breast abnormalities before VAEB, and help to reduce malignancy underestimation of B3.

Three-year Trends in Diagnosis of B3 Breast Lesions and Their Upgrade Rates to Malignant Lesions

BACKGROUND

B3 breast lesions are a heterogeneous group with uncertain malignant potential and, as such, provide a source of diagnostic difficulty. We calculated the prevalence of B3 lesions at our center along with the upgrade rates (positive predictive value) to in situ or invasive malignancy.

MATERIALS AND METHODS

We searched our pathology database over a 3-year period to include all B3 biopsies. The subsequent excision for each biopsy was reviewed, and the rate of upgrade was calculated by subtype. These results were compared against data published in large United Kingdom studies.

RESULTS

A total of 9206 breast biopsies were identified, of which 614 (6.7%) were classified as B3. Lesions displaying epithelial atypia were the most common subtype of lesion, with a prevalence of 39.6%. Lesions displaying epithelial atypia were upgraded to malignancy in 35.7% of cases. Among non-atypical cases, papillary lesions were the most common diagnosis (32.1%) with an upgrade rate of 2%. In situ lobular neoplasia (10.4%) was the third most frequently encountered diagnosis, and was upgraded to malignancy in 10.9% of cases. The upgrade rate in the remaining non-atypical lesions was invariably low (0%-2.6%).

CONCLUSIONS

Herein, we have shown an overall B3 rate in keeping with published data, whereas lesions displaying epithelial atypia showed upgrade rates to malignancy comparable with that of large United Kingdom studies. In our study, lesions without epithelial atypia showed very low rates of upgrade. A wide range of upgrade rates is seen in cases of lobular neoplasia, which highlights the need for uniformity of nomenclature and reporting within this subtype to accurately ascertain the true risk of upgrade associated with these lesions.

Second International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

Purpose

The second International Consensus Conference on B3 lesions was held in Zurich, Switzerland, in March 2018, organized by the International Breast Ultrasound School to re-evaluate the consensus recommendations.

Methods

This study (1) evaluated how management recommendations of the first Zurich Consensus Conference of 2016 on B3 lesions had influenced daily practice and (2) reviewed current literature towards recommendations to biopsy.

Results

In 2018, the consensus recommendations for management of B3 lesions remained almost unchanged: For flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL) and radial scars (RS) diagnosed on core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB), excision by VAB in preference to open surgery, and for atypical ductal hyperplasia (ADH) and phyllodes tumors (PT) diagnosed at VAB or CNB, first-line open surgical excision (OE) with follow-up surveillance imaging for 5 years. Analyzing the Database of the Swiss Minimally Invasive Breast Biopsies (MIBB) with more than 30,000 procedures recorded, there was a significant increase in recommending more frequent surveillance of LN [65% in 2018 vs. 51% in 2016 (p = 0.004)], FEA (72% in 2018 vs. 62% in 2016 (p = 0.005)), and PL [(76% in 2018 vs. 70% in 2016 (p = 0.04)] diagnosed on VAB. A trend to more frequent surveillance was also noted also for RS [77% in 2018 vs. 67% in 2016 (p = 0.07)].

Conclusions

Minimally invasive management of B3 lesions (except ADH and PT) with VAB continues to be appropriate as an alternative to first-line OE in most cases, but with more frequent surveillance, especially for LN.

First International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

The purpose of this study is to obtain a consensus for the therapy of B3 lesions. The first International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions) including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL), benign phyllodes tumors (PT), and radial scars (RS) took place in January 2016 in Zurich, Switzerland organized by the International Breast Ultrasound School and the Swiss Minimally Invasive Breast Biopsy group-a subgroup of the Swiss Society of Senology. Consensus recommendations for the management and follow-up surveillance of these B3 lesions were developed and areas of research priorities were identified. The consensus recommendation for FEA, LN, PL, and RS diagnosed on core needle biopsy or vacuum-assisted biopsy (VAB) is to therapeutically excise the lesion seen on imaging by VAB and no longer by open surgery, with follow-up surveillance imaging for 5 years. The consensus recommendation for ADH and PT is, with some exceptions, therapeutic first-line open surgical excision. Minimally invasive management of selected B3 lesions with therapeutic VAB is acceptable as an alternative to first-line surgical excision.

Voluminous Incidental Oncocytic Neoplasm of the Adrenal Gland With Uncertain Malignant Potential

A 74-year-old man presented with right flank pain and a palpable mass in the left flank. Blood pressure was normal. Contrastenhanced computed tomography (CT) showed a 17 × 16 × 12 cm retroperitoneal mass over the left kidney, solid and heterogeneous. There were also 3 retro aortic lymph nodes and bilateral renal lithiasis. Twenty four-hour urinary metanephrines and normetanephrines were normal. The patient underwent a resection of the mass with left adrenalectomy by a lumbar incision. Histological findings revealed an adrenal oncocytic neoplasm (AON) with uncertain malignant potential. Six months after surgery, CT control showed neither local nor distant recurrence.

Uterine smooth muscle tumors of uncertain malignant potential (STUMP): pathology, follow-up and recurrence

The term smooth uterine muscle of uncertain malignant potential (STUMPs) indicates a group of uterine smooth muscle tumors (SMTs) that cannot be diagnosed unequivocally as benign or malignant. Diagnosis, surgical management, and follow-up of this neoplasm remain controversial, especially in pre-menopausal women with fertility desire, due to the non aggressive behaviour and prolonged survival rate when compared to leiomyosarcomas. However, recurrence is estimated between 8.7% and 11% and may include delayed-recurrences. We reported five cases of uterine masses treated by surgical procedure diagnosed as STUMP on final pathology. Four patients underwent a total abdominal hysterectomy with or without salpingo-oophorectomy. One patient underwent excision of uterine mass and subsequent total abdominal hysterectomy plus bilateral salpingo-oophorectomy after the diagnosis of STUMP. All patients in our study remained recurrence-free to date (with a follow up period ranging from 6 to 81 months). Based on our experience and in consideration of the lack of consensus regarding the malignant potential, diagnostic criteria, gold-standard treatment and follow-up, we believe that close multidisciplinary management is mandatory in the event of STUMP. We suggest that gynaecologist, dedicated pathologist (with high level of expertize in gynaecological pathology) and oncologist should work as a team in the counselling and management of this neoplasm from detection till completion of follow up. Furthermore, we recommend immunohistochemistry to investigate the overexpression of p16 and p53 in order to identify the cohort of patients at increased risk of recurrence who may benefit from more aggressive surgical-oncological strategies.

Prostate Stromal Tumor of Uncertain Malignant Potential: Case Report With 5-Year Follow-up

Prostate stromal tumor of uncertain malignant potential is a term used to describe a specialized proliferation of stromal cells within the prostate. Most of these tumors tend to be benign, but some can present with local invasion or progress to prostatic stromal sarcoma with distant metastasis. We report a case of a 62-year-old male patient who presented to us with a diagnosis of stromal tumor of uncertain malignant potential. We have followed up the patient for 5 years with imaging, prostate-specific antigen checks, and annual prostate biopsies.