Multifocal Malignant Epithelioid Mesothelioma of the Testis

Introduction/Objective

Testicular mesothelioma is an extremely uncommon entity, and presents with non-specific clinical symptomatology, including painless scrotal enlargement and hydrocele formation. Testicular mesothelioma arising from the mesothelial cells of the tunica vaginalis accounts for 0.3%-5% of all mesothelioma cases and is often associated with poor prognosis. While the pathophysiology of this entity remains unclear, exposure to asbestos and long-standing hydrocele are associated risk factors.

Methods/Case Report

Herein, we present a case of a 65-year-old male with history of hypertension, 4-year history of left scrotal hydrocele, and a 7-month history of painless, progressively enlarging left scrotum. Scrotal ultrasound revealed a left, septated hydrocele with multiple heterogenous intratesticular masses. A left radical orchiectomy was performed and the specimen was sent to pathology for histopathological evaluation. Gross examination revealed a tan-brown fluid-filled cystic and solid mass measuring 7.5 x 4.0 x 3.5 cm involving the entire epididymis with multiple pink-tan, friable, papillary excrescences and nodules in the intratesticular parenchyma. Microscopic examination revealed a cystic and solid lesion with tubular and papillary architecture comprised of cuboidal cells with cellular pleomorphism, irregular nuclear contour, and dense chromatin involving the epididymis, rete testis, tunica albuginea, the testicular parenchyma including the hilar fat and the spermatic cord stroma. Immunohistochemical staining of the lesion demonstrated positive staining with AE1/AE3, CK7, WT1, PAX8, Calretinin, Vimentin, Podoplanin D2-40, and lack of staining with Chromogranin, Inhibin, MART-1, SMA, AFP, CD99, S100, c-kit, PLAP, HCG, MOC31, BerEP4. Based on the histomorphology and the immunophenotype of the lesion, a diagnosis of an epithelioid-type malignant mesothelioma was favored.

Results (if a Case Study enter NA)

N/A.

Conclusion

Malignant epithelioid mesothelioma of the testis is a rare and important clinical consideration for patients presenting with scrotal lesion, non-specific clinical presentation, and a history of asbestos exposure and/or long- standing hydrocele.

Immunoglobulin G4-Related Disease (IgG4-RD) Mimicking Hyaline Vascular Castleman Disease

Introduction/Objective

Immunoglobulin G4-related disease (IgG4-RD) is a newly emerging immune-mediated fibroinflammatory disease characterized by increased IgG-4+ plasma cells. In soft tissue and visceral organs, the IgG4+ plasma cells often accompany a storiform pattern of fibrosis with obliterative phlebitis. In lymph nodes, rare cases have been described in the literature mimicking Multicentric Castleman Disease.

Methods/Case Report

Herein, we present a case of a 59-year-old male with history of lung adenocarcinoma status post resection one year prior, who presented with several months of unintentional weight loss and worsening of cervical lymphadenopathy. CT scan of the neck demonstrated extensive cervical lymphadenopathy. Incidentally, patient had traveled to a foreign country and had a positive QuantiFERON result. Clinical suspicion was either nodal metastatic disease or TB infection. An excisional biopsy of the left cervical lymph node was performed. Microscopic examination revealed numerous hyperplastic follicles with significant hyaline deposition, concentrically thickened mantle zones, radially penetrating vessels, increased interfollicular vascularity and plasmacytosis; morphologic features commonly associated with Hyaline-Vascular Castleman Disease (HVCD). Additionally, plasmacytosis within germinal center was identified. Immunohistochemical stains demonstrated significant IgG4+ plasma cells (approaching 108/HPF) within the germinal centers. All plasma cells were polytypic.

Results (if a Case Study enter NA)

N/A.

Conclusion

Commonly described patterns for IgG4-RD in the literature are multicentric Castleman disease (MCD)-like, whereas, in our case, we present intrafollicular plasma cell proliferation pattern of IgG4-RD with classic background features of HVCD. Accurate diagnosis and distinction between these two entities is imperative for prognostication, treatment and clinical management of IgG4-RD.

Recurrent Small Bowel Obstruction and Perforation as a Complication of EFEMP1-Associated Systemic Venous Amyloidosis

Introduction/Objective

Amyloidogenic protein EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) is a newly described age-related systemic venous amyloidosis. EFEMP1 venous deposition has recently been reported in postmortem gastrointestinal specimens in which the deceased presented with gastrointestinal bleeding.

Methods/Case Report

We report a case of a 53-year-old female with long-standing seronegative spondylitis, and multiple recurrent small bowel obstructions and perforations status post surgical interventions who presented with 3 days of generalized abdominal pain, 10/10 in severity with nausea, emesis and absence of bowel movement. Abdominal CT scan confirmed closed loop obstruction in the left hemi-abdomen. An emergent partial duodenectomy was performed with extensive lysis of adhesion which revealed a perforated jejunal diverticulum with abscess formation. Microscopic examination demonstrated the presence of eosinophilic, amorphous, acellular material in the venules of the duodenum wall. Congo red stain demonstrating the presence of amyloid deposits and the specimen was sent for amyloid typing. Liquid chromatography tandem mass spectrometry demonstrated a peptide profile consisting of serum amyloid P, apolipoprotein A4, apolipoprotein E, and abundant peptides associated with EFEMP1/FBLN3 consistent with a recently described age-related venous amyloidosis derived from EFEMP1 protein.

Results (if a Case Study enter NA)

N/A.

Conclusion

EFEMP1-associated systemic venous amyloidosis has a predilection for females with a median age of 75 years and almost exclusively occurs in the gastrointestinal tract. We report this case for its novelty, unique clinical presentation and to emphasize awareness of this entity as we learn more about its etiology, presentation, management, and prognostication.

Paravertebral Pseudoendocrine Sarcoma

Introduction/Objective

Pseudoendocrine sarcoma is a rare and newly described, emerging entity occurring predominantly in middle-aged to elderly males with apredilection for the thoracic paravertebral soft tissue. Pseudoendocrine sarcoma is a recently recognized intermediate-grade sarcoma with CTNNB1 mutations.

Methods/Case Report

Herein, we present a case of a 66-year-old male with a 10-year history of a progressively enlarging, painful, mid-back lesion. CT scan of the chest demonstrated a right paraspinal soft tissue mass measuring 9.5 x 5.5 x 4.5 cm located at the level of T8-T11. An image-guided biopsy was performed revealing monotonous, epithelioid cells, with round hyperchromatic nuclei, eosinophilic, granular cytoplasm, and indistinct borders arranged in rosettes. Mitoses, necrosis and lymphovascular invasion were not identified.The tumor cells were positive for Beta- catenin, CD56, BCL-2, BCL-6, CD4, CD34 and CD 68, and had a low-proliferative index. The neoplastic cells lacked staining with CK-AE1/AE3, CAM-5.2, NKX3.1, PAX8, Chromogranin, Synaptophysin, NSE, EMA, CD3, CD7, PAX5, and inhibin. The morphology and the immunophenotype support the diagnosis of pseudoendocrine sarcoma.

Results (if a Case Study enter NA)

N/A.

Conclusion

To date, few cases have been described in the literature. Recognition of this entity is important due to the potential for local recurrence (43%), and regional and distant metastasis. Complete excision of the lesion as well as adequate patient surveillance is imperative as we gain more understanding of the metastatic potential and prognosis of this emerging entity.

Small Bowel Obstruction as a Rare Complication of Progressive Sclerosing Mesenteritis

Introduction/Objective

Sclerosing Mesenteritis is an uncommon, idiopathic, localized inflammatory syndrome involving the small intestine and colonic mesentery. It is considered a benign condition that commonly occurs in elderly with a gender predilection for males, and its etiology remains unknown. Small Bowel Obstruction (SBO) is a rare, unexpected, but detrimental complication of progressive Sclerosing Mesenteritis. Herein, we present a case of an enlarging, progressive Sclerosing Mesenteritis with extensive involvement of the small bowel and mesentery requiring two consecutive major surgical interventions.

Methods/Case Report

A 72-year-old male with Myelodysplastic Syndrome (MDS) and recent history of loop ileostomy due to distal intestinal obstruction secondary to enlarging Sclerosing Mesenteritis, presented to our institution with non-specific symptoms of worsening abdominal pain and multiple episodes of gastrointestinal bleeding. Radiographic investigation revealed SBO and he subsequently underwent exploratory laparotomy resulting in total enterectomy with excision of mesenteric mass, extended right colectomy, Whipple procedure, and gastrostomy. The specimens were sent to pathology for histopathological evaluation and gross examination revealed several bosselated, tan-white, firm and rubbery, fibrotic lesions with associated lobulated fibroadipose tissue. Microscopic examination showed extensive mesenteric fibrosis with dense bundles of collagen fibers, areas of fat necrosis, mucosal ischemia and calcification involving the small bowel and serosal surface of large intestine and peritoneum. The lesional cells showed minimal atypia, mitoses, and lacked the Beta-catenin nuclear staining seen in mesenteric fibromatosis. Given the clinical history and histopathological findings of the lesion, we favored the diagnosis of Sclerosing Mesenteritis.

Results (if a Case Study enter NA)

N/A

Conclusion

The etiology of Sclerosing Mesenteritis is not well-understood and there are cases of Sclerosing Mesenteritis reported in the literature in association with trauma, surgery, malignancy, and IgG4-related disease. Our patient’s post-operative history was complicated by short gut syndrome, and he is currently requiring small bowel transplant. We report this case for its unusual and aggressive clinical presentation, and to heighten clinical awareness for detrimental consequences of this seemingly benign condition.

Hyperhemolysis Syndrome Following Pre-Operative Red Blood Cell Exchange

Introduction/Objective

Pre-operative red blood cell exchange (RBCX) for patients with Sickle Cell Disease (SCD) is a category III indication. In our institution, RBCX is routinely performed pre-operatively when general anesthesia is necessary with the goal of HbS%<30 and reduction in adverse events related to general anesthesia. In the context of elective surgery, the risks and benefits of both the operation and any pre-operative transfusion must be discussed with the patient. Herein, we present an extreme case of Hyperhemolysis Syndrome resulting from a pre-operative RBCX.

Methods/Case Report

A 23-year-old transgender female with SCD (Hb S Lepore) treated with Hydroxyurea presented for elective breast augmentation for gender-affirmation. Her pre-operative plan included a RBCX. Her pre-exchange hemoglobin (Hb) and hematocrit (Hct) were 10.3 g/dL and 29.3%, respectively. Hb electrophoresis revealed HbS 52%, HbF 41.4%, HbA2 7.4%, and HbA was not detected. Type and Screen (T&S) demonstrated O + blood group, with a negative antibody screen, and with no known historical alloantibodies.

RBCX was performed using the Spectra Optia (TerumoBCT, Lakewood, CO, USA) with exchange volume of 1.9 L of group O+ RBCs, phenotypically matched for C, E, and K, an end Hct of 30% and an FCR of 30%. Her post-exchange Hb and Hct were 10.2g/dL and 29.5%, respectively. Hemoglobin fractionation revealed HbS 12% and HbA 73%.

She underwent surgery without intraoperative complications. Two weeks post RBCX, her Hb had decreased to 5.3 g/dl, and her LDH and Total Bilirubin had increased to 253 ul and 1.8 mg/dl, respectively. A repeat T&S drawn 8 days after RBCX revealed a positive antibody screen and direct antiglobulin test (DAT). Three new alloantibodies were identified: anti-Fya (present in plasma and eluate); anti-Jkb (present in plasma); anti-S (eluate). She was treated with IVIG, 0.4 g/Kg/day for 5 consecutive days and 2 doses of subcutaneous darbepoetin 100 mcg and subsequently discharged with close outpatient follow up. Her Hb returned to baseline at 11 g/dL, 48 days post RBCX.

Results (if a Case Study enter NA)

N/A

Conclusion

Pre-operative RBCX decreases morbidity in sickle cell patients undergoing general anesthesia. In the setting of elective surgery, patients must be counseled on the benefits and risks of surgery as well as the requisite RBCX. In our case, the patient developed multiple alloantibodies, with lifelong implications should she ever need future blood transfusions.

TTF-1 Immunoexpression in Primary Rectal Adenocarcinoma with Brain Metastasis

Introduction/Objective

Rectal adenocarcinoma metastatic to the brain occurs in 0.6%-3% of cases and is associated with advanced-stage disease.TTF-1 expression in rectal adenocarcinoma is an uncommon finding and less than five cases of TTF-1 positive rectal adenocarcinomas have been reported in the literature. Herein, we report a primary rectal adenocarcinoma with biopsy-proven brain metastasis, radiographic evidence of hepatic and pulmonary involvement and unique expression of TTF-1, a marker with high sensitivity for primary pulmonary and thyroid lesions. Furthermore, we discuss the importance of distinguishing this entity from Pulmonary Enteric Adenocarcinoma (PEA).

Methods/Case Report

A 68-year-old male with hypertension presented with a two-day history of left facial drooping and dysarthria. Brain MRI revealed a 2.9 cm, contrast-enhancing, solitary, right insular mass. A pterional craniotomy and gross total resection of the lesion was performed. Microscopic examination revealed metastatic adenocarcinoma with immunohistochemical expression of CAM 5.2, CDX2, CK20, focal immunoreactivity with Napsin A and TTF-1, and lack of expression of CK7 and Synaptophysin. Radiographic investigation revealed a right posterior rectal lesion and multiple hepatic and bilateral pulmonary nodules. Sigmoidoscopy a fungating, partially circumferential, ulcerated, and friable rectal mass extending 6 cm proximally from the anal verge. Biopsy demonstrated invasive well- differentiated rectal adenocarcinoma with microsatellite stable phenotype, expression of CDX2, CD20, TTF-1 in the lesional cells, and lack of immunostaining with CK7. Given these findings, we favored a diagnosis of invasive well- differentiated rectal adenocarcinoma.

Results (if a Case Study enter NA)

N/A

Conclusion

TTF-1 positive rectal adenocarcinoma is an important differential diagnosis for PEA. As the two primary lesions share histomorphological features, clinical history, radiological findings and immunohistochemical staining with CK7 can aid in distinguishing between the two entities. Recent literature suggests a possible role for CDH17 and SATB2 immunostaining to increase the sensitivity and specificity of distinction between the two entities. Lack of expression of CK7 in both the rectal and brain lesion biopsies, radiological finding of numerous bilateral pulmonary infiltrates and one large, solitary rectal mass supports the diagnosis of advanced stage primary rectal adenocarcinoma with distal metastasis in our patient.

An Uncommon Case of Colonic Neuroendocrine Carcinoma with Scalp Metastasis

Introduction/Objective

Neuroendocrine neoplasms of the colon account for <1% of all colorectal malignancies. While visceral metastasis of neuroendocrine neoplasms is commonly observed, cutaneous distant metastasis has infrequently been reported and correlates with an advance stage and progression of disease. To our knowledge, there have been only 10 cases of neuroendocrine neoplasms with metastasis to the scalp reported in the literature. Herein, we report an unusual case of colonic neuroendocrine carcinoma with scalp metastasis, that can be microscopically indistinguishable from the highly aggressive cutaneous neuroendocrine carcinoma, Merkel Cell Carcinoma.

Methods/Case Report

A 47-year-old female with a history of ileocecal neuroendocrine carcinoma and status post right hemicolectomy had developed liver metastasis and subsequently had an orthotopic liver transplant. PET scan later revealed multiple areas of increased activity involving the ribs, scalp and cervical lymph node that were concerning for malignancy. The scalp lesion consisted of a 7mm non-tender, mobile, violaceous, erythematous dermal nodule that was clinically concerning for cutaneous metastasis. A skin punch biopsy microscopically revealed a subcutaneous infiltrate of nests composed of neoplastic monotonous blue cells with the classic nuclear “salt and pepper” chromatin and scant eosinophilic cytoplasm. The lesional cells showed positive immunoreactivity for synaptophysin and chromogranin. With the given patient’s clinical history and presentation, the observed histological findings and immunophenotypic expression of the tumor cells supported a diagnosis of metastatic neuroendocrine carcinoma.

Results (if a Case Study enter NA)

N/A

Conclusion

Metastatic neuroendocrine carcinoma to the scalp is a rare entity and is infrequently encountered in dermatopathology. Given the location and the gross appearance of the scalp lesion, a wide differential diagnosis would include both benign and malignant tumors. In particular, Merkel Cell Carcinoma can grossly and histologically mimic metastatic colonic neuroendocrine carcinoma. Both entities would show synaptophysin and chromogranin uptake. However, metastatic tumors originating from the colon will demontrate CDX2 and SATB2 nuclear staining. We share this rare case of metastatic colonic neuroendocrine carcinoma as it is an important differential diagnosis for primary cutaneous Merkel Cell Carcinoma.

Cutaneous Eccrine Adenolipoma with a Spindle Cell Component

Introduction/Objective

Cutaneous adenolipoma is a rare, benign variant of solitary lipoma characterized by a mature adipocytic proliferation with entrapped eccrine or apocrine sweat glands. It is found predominately in middle-aged females, with a predilection for lower extremities including the thigh and gluteal regions. Cutaneous adenolipoma is presumed to be a hamartomatous process. Herein, we report a unique case of a cutaneous eccrine adenolipoma with a spindle cell component, namely, an early evolving spindle cell adenolipoma.

Methods

A 43-year-old female with a recurrent history of hidradenitis presented with a 2.7 cm x 1.5 cm x 0.7 cm soft, mobile nodule on the right posterior thigh. It had been present for at least four months and clinically resembled a lipoma. An excisional punch biopsy was performed for pathological evaluation. A concurrent nevus lipomatosus superficialis was diagnosed from the right perineum.

Results

Gross examination of the thigh nodule revealed fragments of a tan-yellow, lobulated, fatty lesion. Microscopic examination demonstrated a benign lipomatous proliferation with entrapped eccrine glands associated with a surrounding spindle cell stroma. Initial differential diagnosis included a cutaneous eccrine adenolipoma variant and a cutaneous mixed solitary hamartoma composed of admixed neural, eccrine and lipomatous components.

Immunohistochemical staining showed uptake for CD34 and CD10 in the spindle cell stromal component, but negative for desmin and S100. Based on our histopathological findings, our diagnosis of an eccrine cutaneous adenolipoma with a spindle cell component was rendered. This unique lesion displayed features of an evolving spindle cell lipoma with entrapped sweat glands, which may be viewed as an early stage of a dermal spindle cell adenolipoma.

Conclusion

Cutaneous eccrine adenolipoma is a rare, benign lipomatous neoplasm with entrapped sweat glands that can also show a spindle cell component. We share this rare lesion exemplifying the histomorphological spectrum of a lipomatous hamartoma and to highlight the recognition of a cutaneous adenolipoma.

Pyoderma Gangrenosum as the Initial Presentation of Inflammatory Bowel Disease

Introduction/Objective

Pyoderma gangrenosum is a neutrophilic dermatosis, commonly associated with arthritis, psoriasis, and systemic lupus erythematosus. It is also an aggressive manifestation of extra-intestinal inflammatory bowel disease affecting less than 5% of patients with ulcerative colitis and Crohn disease. We present a case of pyoderma gangrenosum as an initial and rapidly progressive manifestation of Crohn disease.

Methods

A 35-year-old man presented with fecal urgency, periumbilical pain, and frequent diarrhea, with stool cultures revealing no infectious etiology. Colonoscopy demonstrated active inflammatory bowel disease consistent with Crohn disease. Concurrently, patient developed an ulcer on right lower extremity not otherwise contributed to history of trauma or injury. Biopsy of right lower extremity ulcer revealed histopathologic findings consistent with pyoderma gangrenosum. Despite medical management, and prolonged use of wound care and wound vac, patient’s non-healing ulcer continued to geographically expand, resulting in ankle contracture. A right below the knee amputation was performed and amputation specimen was sent to pathology for further diagnostic evaluation.

Results

Gross examination revealed an extensive cutaneous ulcer measuring 22.1cm x 11.7cm x 0.3cm and involving the anterior medial aspect of the right lower extremity with medial and posterior extension down to the dorsum of the foot with broad deep tissue destruction and exposure of fascia and tendon. Microscopic examination revealed severe ulceration, suppurative necrosis, superficial and deep vasculitis confined to the ulcer bed.

Surrounding soft tissue revealed chronic myopathic changes secondary to ischemia. Foci of commensal filamentous gram-positive bacterial colonization in a nidus of necrosis were also identified. The inflammatory pattern involved predominantly neutrophils with weak recruitment of other inflammatory cells, consistent with pyoderma gangrenosum.

Conclusion

This case highlights the debilitating extent of Crohn disease, its detrimental effects on the patient’s quality of life, and the diagnostic and treatment challenges it poses to clinicians in managing Crohn disease and its complications.

Alterations of Hemoglobin Fractionation in a Sickle Cell Disease Patient on Voxelotor Therapy

Introduction/Objective

Voxelotor is a molecule that allosterically binds to the alpha-chain of hemoglobin, resulting in increased oxygen affinity. This allosteric inhibition leads to prevention of hemoglobin polymerization and sickling of red blood cells in response to low oxygen tension. Voxelotor has been used to treat patients with Sickle Cell Disease (SCD) and recent literature indicates it may contribute to complex hemoglobin fractionation (HF) elution patterns. We report a novel case of a SCD patient on concurrent Hydroxyurea, Voxelotor and chronic RBC exchange transfusion treatment and discuss the implications of these three treatment modalities on HF and monitoring of SCD.

Methods

A 17-year-old female with SCD complicated by frequent vaso-occlusive crisis, and avascular necrosis managed with chronic RBC exchange and Hydroxyurea. Her HF prior to initiation of Voxelotor treatment showed 3.2% HbA2, 51% HbA, 6.0% HbF, and 41% HbS. Voxelotor therapy was initiated at 1500mg/day and HF was performed 10 days later. Whole blood was collected and subjected to High Performance Liquid Chromatography (HPLC) with reflex to RBC solubility and Capillary Electrophoresis.

Results

HF performed post-Voxelotor therapy revealed positive sickle solubility with a complex pattern of 2.7% HbA2, 49.2% HbA, 5.3% HbF, 15.7% HbS, 0% HbC, and two additional peaks of a 6.3% peak in the window-D region (retention time of 4.34) and 20.8% of an atypical Hb peak pattern (at the retentuin time of 4.18). The results reflected a complex HF of a HbSS patient on concurrent chronic RBC exchange transfusion, hydroxyurea therapy, and Voxelotor treatment. Post Voxelotor-therapy HF revealed a reduction in HbS from 41% to 15.7% with the emergence of two additional peaks. Chronic RBC exchange transfusion and Hydroxyurea treatment account for the observed fractionation of HbA and HbF, respectively. Based on recent literature, we attribute the emergence of the two additional peaks to Voxelotor therapy. All three therapies led to reduction in HbS.

Conclusion

Routine HF serves as an essential modality in diagnosis and monitoring of SCD. Voxelotor treatment alters the HF profile and may cause difficulty for interpretation. With the emergence of novel therapies, it is imperative for clinicians to provide medication information to clinical laboratories and pathologists to be fully aware of the effects of current treatments to correctly interpret and monitor SCD.

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using RBSC for fully 3D compensation has resulted in prohibitively long reconstruction times. In this work we propose two new methods that can be used in conjunction with existing methods to achieve marked reductions in RBSC reconstruction times. The first method, coarse-grid scatter modelling, significantly accelerates the scatter model by exploiting the fact that scatter is dominated by low-frequency information. The second method, intermittent RBSC, further accelerates the reconstruction process by limiting the number of iterations during which scatter is modelled. The fast implementations were evaluated using a Monte Carlo simulated experiment of the 3D MCAT phantom with 99mTc tracer, and also using experimentally acquired data with 201Tl tracer. Results indicated that these fast methods can reconstruct, with fully 3D compensation, images very similar to those obtained using standard RBSC methods, and in reconstruction times that are an order of magnitude shorter. Using these methods, fully 3D iterative reconstruction with RBSC can be performed well within the realm of clinically realistic times (under 10 minutes for 64 x 64 x 24 image reconstruction).