Neurofibroma with glomus-like bodies: A novel association-Thoughts about origin.

A neurofibroma with focal glomus-like body differentiation is an unusual phenomenon recently encountered in an excision specimen from the right lateral distal forearm of a 26-year-old man. Glomus cells are modified smooth muscle cells normally present in glomus-like bodies but can also be found in glomus tumors (GT) or lesions considered in the spectrum of GT, including myopericytoma, myofibroma, and angiolipoma. Neurofibromas are peripheral nerve sheath tumors derived from the neural crest cells. While both GT and its variants and neurofibroma are thought to be derived from different cell types, there is growing evidence that glomus cells have a neural crest origin. This is based on multiple theories, with some overlapping pathways, including neural crest cell differentiation, Schwann cell reprogramming, VEGF expression, and NF1 gene biallelic inactivation. This report adds to the growing evidence of possible neural crest origin for glomus cells and would help explain finding glomus-like bodies scattered through a neurofibroma.

Chronic Radiation Dermatitis Secondary to Narrow-Band Ultraviolet B Therapy in a Patient With Primary Cutaneous CD8 + T-Cell Lymphoma With Cytotoxic Granules.

ABSTRACT: Conventional therapies for CD8 + cutaneous T-cell lymphoma include topical steroids, topical nitrogen mustard, topical bexarotene, ultraviolet B therapy, psoralen and ultraviolet A therapy, local radiotherapy, and interferon alfa; however, these treatments are often found to be ineffective. Presented is a case of CD8 + cutaneous T-cell lymphoma with near-complete response to narrow-band ultraviolet therapy because of chronic radiation dermatitis initially believed to be possible progression of a CD8 + cutaneous epidermotropic cytotoxic T-cell lymphoma.

BerEP4-Negative Basal Cell Carcinoma: An Immunophenotype Not to Forget.

ABSTRACT: Basal cell carcinoma (BCC) is the most common cancer worldwide. Although not typically metastatic, BCC can be locally destructive. BerEP4 is an antibody against CD326, an epithelial cell adhesion molecule (EpCAM) that is expressed on epithelial progenitor cells and carcinomas. BerEP4 has been reported to have a 100% positive sensitivity in basal cell carcinomas, but a much lower sensitivity for a variety of other carcinomas, including clear cell renal cell carcinoma and metastatic renal cell carcinoma. A 74-year-old woman presented with a BerEP4-negative, but anti-renal cell antibody-positive BCC, and the stark clinical implications of misdiagnosis. This case stresses the importance of considering BerEP4-negative BCC, even when other abnormal features are present.

Lenalidomide-induced symmetrical drug-related intertriginous and flexural exanthema.

Symmetric drug-related intertriginous and flexural exanthema (SDRIFE) is a cutaneous drug reaction that presents with symmetrical erythema in the flexures. The reaction typically appears hours-to-days after drug exposure but has been reported to occur months after drug initiation. Diagnostic criteria include cutaneous reaction after exposure to a systemic drug, erythema of the gluteal region and/or V-shaped erythema of the inguinal areas, involvement of an additional intertriginous site, symmetry, and absence of systemic involvement. The rash typically presents as macular erythema. However, variations in morphology have been reported including papules, pustules, vesicles, and bullae. The histopathology of SDRIFE is non-specific and the diagnosis is made clinically. Cessation of the causative drug leads to gradual rash resolution. Beta-lactam antibiotics are the most implicated medications but case reports describe SDRIFE following monoclonal antibodies, chemotherapeutic agents, and various other medications. We present a patient with SDRIFE secondary to lenalidomide, an immunomodulatory agent. This case highlights the importance of considering SDRIFE in the differential diagnosis of patients presenting with intertriginous erythema.

Radiation-Induced Eccrine Squamous Syringometaplasia With Perineural Invasion.

ABSTRACT: Eccrine squamous syringometaplasia (ESS) is a benign metaplastic reaction of eccrine ducts that occurs in response to injury and can be a histologic mimic of squamous cell carcinoma (SCC). Reported is an 82-year-old man undergoing Mohs surgery for presumed SCC diagnosed in a field of radiation dermatitis. After 3 Mohs stages, the peculiar squamous proliferation was recognized as ESS and the procedure was aborted. Complicating the interpretation of the Mohs frozen section was the presence of perineural invasion because perineural invasion has not been previously reported to occur with ESS. The histologic features used to distinguish ESS from SCC are discussed.

Novel teprotumumab treatment of severe thyroid dermopathy; ototoxicity as an adverse side effect.

Pretibial myxedema, more generally thyroid dermopathy, results from mucopolysaccharide accumulation in the dermis, typically between the knee and dorsal foot. Thyroid dermopathy presents in Graves disease, but can occur in Hashimoto thyroiditis, primary hypothyroidism, and euthyroid patients. Treatment of thyroid eye disease with teprotumumab is established in the literature, with few case reports also showing improvement in pretibial myxedema. Reported is a 76-year-old man with thyroid eye disease and pretibial myxedema treated with teprotumumab; improvement was demonstrated in both conditions. He developed "muffled" hearing as an adverse effect, a complication not widely published in the dermatology literature. At 18 months post-treatment, his symptoms are stable without recurrence, but hypoacusis persists. Given the long-term efficacy and side-effects, dermatologists should recognize the potential benefits and risks of using teprotumumab for thyroid dermopathy. A baseline audiogram may be considered prior to therapy. Additionally, longitudinal data is needed to document the benefits and risks of this novel therapy.

Myxoid perineurioma: an entity with many mimics.

We present a case of a female patient who presented with a 0.6cm flesh-colored "rubbery" papule on the left thigh. Biopsy revealed a dermal myxoid tumor containing spindled cells, tapered nuclei, indistinct cell borders, and a large number of mast cells. The spindle cells stained negative for S100 protein and Sox10 on immunohistochemistry, excluding myxoid neurofibroma, but positive for epithelial membrane antigen (EMA), and CD34, supporting a diagnosis of myxoid perineurioma. Interestingly, the mast cells showed cytoplasmic and nuclear positivity for microphthalmia transcription factor (MiTF). The lesion was fully excised one year later with identical histopathology and ancillary immunohistochemical profile.

Pseudolymphoma to Lymphoma: A Case of Chronic Reactive Lymphoid Hyperplasia Transforming to Primary Cutaneous Marginal Zone Lymphoma.

ABSTRACT: Primary cutaneous marginal zone lymphoma (PCMZL) is a low-grade malignant B-cell lymphoma that originates from the skin. It often presents as erythematous solitary or multiple papules, nodules, and/or plaques. It is one of the 3 main subtypes of primary cutaneous B-cell lymphomas. PCMZLs are believed to develop from chronic antigenic stimulation such as from tick-borne bacteria, vaccines, tattoo pigment, or other foreign body. In addition, cutaneous lymphoid hyperplasia, a documented precursor to malignant PCMZL, often presents in response to areas of chronic inflammation. Cutaneous lymphoid hyperplasia and PCMZL share several clinical and histological similarities that require clinicopathologic suspicion, immunohistochemical ancillary studies, and histopathologic analysis to accurately differentiate the 2 entities. Although gene rearrangement studies have historically been of limited value in the diagnosis of PCMZL, recent studies investigating molecular markers have identified the presence of multiple genetic abnormalities that have helped to better characterize the disease and aid in diagnosis. In addition, newer studies have found associations between PCMZL and gastrointestinal disorders, including Helicobacter pylori and inflammatory bowel disorders. In this article, we describe a case of a 56-year-old patient with a history of ulcerative colitis presenting with chronic reactive lymphoid hyperplasia that transformed to primary cutaneous marginal zone lymphoma.

Persistent diarrhea with petechial rash - unusual pattern of light chain amyloidosis deposition on skin and gastrointestinal biopsies: A case report.

BACKGROUND: Amyloidosis is a rare disease characterized by extracellular deposition of misfolded protein aggregated into insoluble fibrils. Gastrointestinal involvement in systemic amyloidosis is common, but is often subclinical or presents as vague and nonspecific symptoms. It is rare for gastrointestinal symptoms to be the main presenting symptom in patients with systemic amyloidosis, causing it to be undiagnosed until late-stage disease. CASE SUMMARY: A 53 year-old man with diarrhea, hematochezia, and weight loss presented to a community hospital. Colonoscopy with biopsy at that time was suspicious for Crohn disease. Due to worsening symptoms including nausea, vomiting, and a new petechial rash, an abdominal fat pad biopsy was done. The biopsy showed papillary and adnexal dermal amyloid deposition, in a pattern usually seen with cutaneous amyloidosis. However, Cytokeratin 5/6 was negative, excluding cutaneous amyloidosis. The patterns of nodular amyloidosis, subcutaneous amyloid deposits and perivascular amyloid were not seen. Periodic Acid-Schiff stain was negative for lipoid proteinosis, Congo red was positive for apple green birefringence on polarization and amyloid typing confirmed amyloid light chain amyloidosis. Repeat endoscopic biopsies of the gastrointestinal tract showed amyloid deposition from the esophagus to the rectum, in a pattern usually seen in serum amyloid A in the setting of chronic inflammatory diseases, including severe inflammatory bowel disease. Bone marrow biopsy showed kappa-restricted plasma cell neoplasm. CONCLUSION: Described is an unusual presentation of primary systemic amyloidosis, highlighting the risk of misdiagnosis with subsequent significant organ dysfunction and high mortality.

Interstitial Mycosis Fungoides: An Unusual Mimic of Interstitial Granuloma Annulare Not to Miss.

Interstitial mycosis fungoides is a rare histopathologic variant of mycosis fungoides that may resemble interstitial granuloma annulare, inflammatory morphea, and interstitial granulomatous dermatitis. Reported is a case of a 62-year-old African American female who presented with an asymptomatic, progressive rash of the left underarm and abdomen with histologic features suggestive of granuloma annulare. Biopsies revealed an interstitial pattern of cells in the dermis with prominent small aggregates of atypical lymphocytes, a few atypical lymphocytes in the lower epidermis, and a mild increase in dermal mucin. Immunohistochemistry staining revealed the atypical lymphocytes to be positive for CD3 and CD8 and negative for CD4 and CD7, an aberrant immunoprofile. Mixed in the dermis with the atypical lymphoid cells were a few CD68 positive histiocytes and S100 protein positive dermal dendritic cells. T-cell receptor beta gene rearrangement studies showed nearly the same clonal peaks for TCRB rearrangement in two biopsy specimens from separate sites, all supporting a diagnosis of interstitial mycosis fungoides. The patient is undergoing treatment with full body narrowband UVB (nbUVB) phototherapy with notable improvement in skin discoloration and resolution of several abdominal lesions. A diagnosis of interstitial mycosis fungoides is challenging to make based on clinical features alone and is often clinically misdiagnosed. Awareness of histopathologic features is critical to make an accurate diagnosis and thus patient management.

Vanishing Bile Duct Syndrome Associated With Estrogen.

Vanishing bile duct syndrome (VBDS) refers to a form of cholestatic liver disease with many etiologies. Vanishing bile duct syndrome is characterized by biliary ductopenia and chronic cholestasis. This is a challenging condition for clinicians because of its rarity and unclear pathophysiology. Presented is an 18-year-old woman who developed cholestatic liver injury and intrahepatic biliary ductopenia after a course of oral contraceptives and intravenous estrogen for uterine bleeding. A year later, this patient did not have significant improvement in liver biomarkers and was referred for transplantation.

Iatrogenic Leptomeningeal Carcinomatosis Following Craniotomy for Resection of Metastatic Serous Ovarian Carcinoma: A Systematic Literature Review and Case Report.

Metastasis of ovarian carcinoma to the central nervous system occurs in <2% of cases and classically localizes within the brain parenchyma. Moreover, leptomeningeal spread of these tumors is an exceedingly rare phenomenon. Here, we conduct a systematic review of the current literature on the natural history, treatment options, and proposed pathogenic mechanisms of leptomeningeal carcinomatosis in ovarian carcinoma. We also report a case of a 67-year-old female with stage IV metastatic ovarian serous carcinoma initially confined to the peritoneal cavity with a stable disease burden over the course of three years. Follow-up imaging demonstrated an intracranial lesion, which was resected via craniotomy, and pathology was consistent with the original diagnosis. Three months after surgery, she developed rapidly progressive dizziness, generalized weakness, fatigue, and ataxia. Repeat MRI demonstrated interval development of extensive and diffusely enhancing dural nodularity, numerous avidly enhancing supratentorial and infratentorial lesions, enhancement of the bilateral trigeminal nerves, internal auditory canals, and exit wound from the surgical site into the posterior aspect of the right-sided neck musculature consistent with diffuse leptomeningeal dissemination. The present case highlights that leptomeningeal dissemination of ovarian carcinoma is a potential yet rare consequence following surgical resection of an ovarian parenchymal metastasis. Progressive clinical symptomatology that develops postoperatively in this patient population should prompt urgent workup to rule out leptomeningeal disease and an expedited radiation oncology consultation if identified.