About

Douglas J. Grider, MD, is an Associate Professor in the Department of Basic Science Education at Virginia Tech Carilion School of Medicine and serves as Vice Chair of Basic Science Education. He is also the founding and current dermatopathology director for the VTCSOM dermatology residency and has pioneered the integration of pathology into the VTCSOM Gastroenterology and Hepatology Fellowship. Dr. Grider advises medical students on pathology and pathologist careers and is a strong advocate for a multidisciplinary approach to medical care, often participating in tumor boards, advisory committees, and inflammatory bowel disease conferences. His research interests include cutaneous manifestations of internal diseases, various skin and gastrointestinal syndromes, the genetic basis for colon cancer, Barrett esophagus, and inflammatory bowel disease. He holds positions as President and Managing Partner of Dominion Pathology Associates and site director for dermatology and gastroenterology fellowships at Carilion Clinic and Virginia Tech Carilion School of Medicine.

Research topics

• Biology
• Cancer research
• Radiology
• Medicine
• Internal medicine

Selected publications

• The Challenge of the Small Round Blue Cell Tumor: Answer

  American Journal of Dermatopathology · 2026-02-17

  articleSenior author
  PublisherDOI

• The Challenge of the Small Round Blue Cell Tumor: Challenge

  American Journal of Dermatopathology · 2026-02-17

  articleSenior author
  PublisherDOI

• Subcutaneous Granuloma Annulare in a Middle-Aged Patient: A Case Report

  Cureus · 2026-02-12

  articleOpen access

  Subcutaneous granuloma annulare (SGA) is a rare, benign variant of granuloma annulare, typically seen in children, which presents as asymptomatic subcutaneous nodules with normal overlying skin. The etiology remains unclear despite associations with systemic disease such as diabetes mellitus. Clinicopathologic correlation is crucial to accurate diagnosis. In this report, we present a case of a 53-year-old female patient with tender, bilateral subcutaneous nodules on her elbows. Punch biopsy confirmed the diagnosis of granuloma annulare. The primary management for her condition at the time was focused on observation and conservative care. However, secondary management with intralesional injection of triamcinolone was utilized when her lesions recurred after a window of resolution. Our case highlights an interesting manifestation of granuloma annulare and demonstrates the importance of both clinical and histological evaluation in distinguishing between similar presenting differential diagnoses. Successful treatment is heavily dependent on accurate diagnosis and patients should be monitored for complete resolution.

  PublisherOA PDFDOI

• Pancreatic Panniculitis: Silent Conundrum?

  American Journal of Dermatopathology · 2026-04-13

  articleSenior author

  ABSTRACT: Pancreatic panniculitis is a rare cutaneous manifestation of pancreatic disease, most commonly occurring in patients with acute or chronic pancreatitis or pancreatic neoplasms. In most reported cases, pancreatic pathology is recognized before or concurrent with the onset of skin lesions; less commonly, panniculitis precedes the diagnosis. Histology demonstrates a lobular panniculitis with saponified fat necrosis and anucleate "ghost" adipocytes, findings that are pathognomonic. Clinically, pancreatic panniculitis presents as tender subcutaneous nodules, most often on the lower extremities, and may be accompanied by systemic manifestations such as fever and inflammatory arthritis. We report 2 cases of pancreatic panniculitis occurring in patients without abdominal pain.

  PublisherDOI

• 380 Uncharacterized MYH9 Germline Mutations in a Microcystic Adnexal Carcinoma Mimicker: Benign Deep Syringoid Ductal Proliferation (BDSDP) with Elastic Fiber Aggregation

  Laboratory Investigation · 2026-03-01

  article
  PublisherDOI

• Enhancing a low-cost, minimally invasive screening test for dihydropyrimidine dehydrogenase mutations linked to 5-fluorouracil sensitivity by integrating computational mutation predictions.

  Journal of Clinical Oncology · 2025-01-27

  article

  226 Background: 5-Fluorouracil (5-FU), a common chemotherapy for solid tumors, is metabolized primarily by dihydropyrimidine dehydrogenase (DPD), encoded by the DPYD gene. With > 200 known variants, individuals with nonfunctional DPYD alleles exhibit impaired 5-FU metabolism and are at risk of severe toxicity. Approximately 35% of the population has partial DPD deficiency, and 0.2% completely lack enzymatic activity. Despite this, DPYD genotyping is not standard practice. This study evaluates the use of non-invasive saliva samples for DPYD genotyping and combines AI-based molecular prediction modeling to search for novel variants within DPYD coding region. Saliva samples were collected from fifty-six healthy individuals and from gastrointestinal (GI) cancer patients including a family cohort of nineteen individuals and three unrelated patients undergoing chemotherapy. Methods: gDNA was sequenced for nine DPYD variants reported to reduced or abrogate DPD activity: c.1905+1G > A, c.1679T > G, c.2846A > T, c.1129-5923C > G, c.1236G > A, c.299_302delTCAT, c.703C > T, c.2983G > T, and c.557A > G. cBioPortal was utilized to search the TCGA database for studies involving colon cancer patients with novel DPYD mutations exhibiting a total FIS score of at least 2 or identified through 3D modeling of DPD using PyMol based on their proximity to or the presence of polar contacts within the active site. Putative pathogenic mutations were analyzed using AlphaMissense and ChimeraX to assign a RSMD score, assessing their potential negative impact on DPD function. Results: Computational studies identified three mutations in DPYD from TCGA colon cancer patients with an unknown impact on DPD and a FIS greater than 4 (c.198G > C/T, c.2161G > A, c.2185G > A), suggesting potential disruption of its function. Four mutations (c.424T > G, c.427T > G, c.2460G > C, c.2909C > A) were identified through protein modeling using PyMol, but only two had a FIS greater than 2. Of these seven identified mutations, four (c.198G > C/T, c.2161G > A, c.2185G > A, c.2909C > A) also scored highly using AlphaMissense and ChimeraX. In silico prediction models from VarSome listed c.2185G > A as Pathogenic Moderate and c.2909C > A as Pathogenic Very Strong. Sequencing of saliva samples indicated mutations c.1129-5923C > G and c.1236G > A were present in four and three volunteers, respectively, and c.1905+1G > A in one case. Mutations identified in GI cancer patients were c.1129-5923C > G and c.1236G > A. Conclusions: By combining computational modeling with the analysis of naturally occurring mutations in colon cancer patients, we have successfully identified potentially pathogenic mutations in the DPYD gene. This information can enhance existing clinical diagnostic tests, providing a more comprehensive assessment of DPYD mutations, including novel variants.

  PublisherDOI

• S3802 Weight Loss Medications: When Your Colon Can’t Handle the Pain

  The American Journal of Gastroenterology · 2025-10-01

  article

  Introduction: Glucagon-like peptide-1 (GLP-1) receptor agonists are increasingly used for the management of obesity. While generally well-tolerated, there have been rare reports of GLP-1 receptor agonists associated with ischemic colitis. To the best of our knowledge, there is not enough data as of yet to help identify at risk patients and catch early warning signs of ischemia. We present a case of suspected ischemic colitis associated with tirzepatide use. Case Description/Methods: A 54-year-old woman with history of obesity (on weekly tirzepatide) presented to the hospital for acute-onset hematochezia and lower abdominal pain that did not improve with bowel movements. Symptoms were associated with intermittent diarrhea and nausea. She denied non-steroidal anti-inflammatory drugs (NSAIDs), antiplatelet or anticoagulation use. Vitals were unremarkable. Hgb = 15.4 g/dL, WBC = 12.5 K/uL, and PLT 371 K/uL. Computed tomography (CT) angiogram of the abdomen and pelvis with/without contrast showed colon wall thickening through the descending colon and splenic flexure, with stranding in adjacent peri-colonic fat, compatible with colitis. The celiac axis and mesenteric arteries were all patent without evidence of stenosis. GI was consulted and the patient underwent a colonoscopy the next day, which revealed nonbleeding sigmoid diverticulosis, and severely ulcerated and easily friable mucosa with deep ulcers in the mid transverse to sigmoid colon. Biopsies from the right colon showed benign colonic mucosa. Biopsies from the transverse and left colon biopsies showed an ischemic-type pattern of injury. The hematochezia resolved and the patient was discharged with instructions to down titrate tirzepatide if needed. Discussion: Our patient did not present with any risk factors for ischemia, including infection, hypovolemia, NSAIDs use, or other drug injury. Ischemic injury was thought to be associated with tirzepatide use. It is worth highlighting, that in this patient, the severity of endoscopic disease did not correlate with the clinical presentation and she had no symptoms in the first year on tirzepatide, posing a clinical dilemma for providers prescribing these medications to their patients. Although limited data are available to indicate true causation versus association, it is thought that the gastrointestinal adverse effects of GLP-1 receptor agonists can contribute to the development of colonic ischemia by inducing constipation and volume depletion, resulting in systemic hypotension and subsequent ischemic colitis.

  PublisherDOI

• Rare Mimic of Conjunctivitis: Conjunctival Intraepithelial Sebaceous Carcinoma

  Case Reports in Ophthalmological Medicine · 2025-01-01

  articleOpen accessSenior authorCorresponding

  Sebaceous carcinoma, an uncommon malignant neoplasm, often arises de novo from periocular sebaceous glands. Commonly manifesting as diffuse eyelid thickening, sebaceous carcinoma can mimic other inflammatory processes such as persistent chalazion or blepharitis. Delayed diagnosis often complicates the disease course due to its indolent presentation. Described is a rare case of sebaceous carcinoma entirely confined to the conjunctival epithelium of the upper eyelid. An 80-year-old female presented for evaluation of bothersome "cysts" under her left upper lid as well as blurry vision in her left eye. The patient was repeatedly re-evaluated over the next few months and found to have Meibomian gland dysfunction of the upper and lower left eyelids as well as 3+ diffuse spongy papillary injection of the tarsal conjunctiva in the left upper lid, with large papillae and conjunctival thickening in the left inferior fornix. A conjunctival biopsy was eventually performed when appropriate management of presumed conjunctivitis failed to alleviate the patient's symptoms. Pathological examination of the left upper eyelid tarsal conjunctiva showed epithelium largely replaced by pagetoid spread of intraepithelial sebaceous carcinoma, with an underlying band-like lymphocytic infiltrate. The carcinoma was strongly adipophilin positive with variable EMA, PRAME, and Factor XIIIa positivity, confirming intraepithelial sebaceous carcinoma. The nuclei of the carcinoma had a smudged, salt-and-pepper appearance; however, CK20, INSM-1, and synaptophysin were negative, excluding Merkel cell carcinoma. A sebaceous carcinoma limited to conjunctival epithelium is rare. However, given its potential aggressive nature, it should be included in the differential diagnosis of "nonhealing conjunctivitis" or persistent unilateral irritation of the eyelid.

  PublisherOA PDFDOI

• Vancomycin-Induced Linear IgA Bullous Dermatosis Mimicking Stevens–Johnson Syndrome Associated With Anticancer Therapy

  American Journal of Dermatopathology · 2025-06-26 · 1 citations

  articleSenior author

  ABSTRACT: Linear IgA bullous dermatosis (LABD), also known as linear IgA disease, is a subepidermal blistering disorder presenting with linear deposits of IgA along the basement membrane zone. Although LABD is commonly idiopathic, it can also rarely be triggered by certain drugs, including vancomycin. Herein, we document the rare case of a 41-year-old woman with a history of invasive ductal breast carcinoma, receiving an anticancer regimen of pembrolizumab, cyclophosphamide, and doxorubicin, who developed erythema, tense bullae, and extensive sloughing of skin after vancomycin therapy. Initially, the patient was suspected to have drug-induced Stevens-Johnson syndrome/toxic epidermal necrosis; however, biopsies of the right thigh revealed subepidermal bullous dermatosis with neutrophils and necrotic keratinocytes. Direct immunofluorescence revealed 3+/3+ anti-IgA and 1+/3+ anti-C3 deposits that were linear at the dermal-epidermal junction. The clinical and histopathologic findings confirmed the diagnosis of vancomycin-induced LABD. This report examines the complicated relationship between immunobullous disease, neoplasms, and oncologic treatment. Presented is a rare case of vancomycin-induced LABD in a patient receiving concurrent chemotherapy and immunotherapy. Clinician awareness of the increased susceptibility of vancomycin-induced LABD in this population subset can improve clinical outcomes and decrease morbidity/mortality.

  PublisherDOI

• Vulvar Nocardiosis in the Setting of dVIN: A High-Risk Infection

  American Journal of Dermatopathology · 2025-09-19

  articleSenior author

  ABSTRACT: Nocardia is a Gram positive, aerobic, partially acid-fast filamentous bacteria of the order Actinomycetales. It is a saprophytic organism found in environmental contaminants such as soil and decomposing organic matter. Primary cutaneous nocardiosis is uncommon and may occur through contamination of a wound or through inhalation of the organism with dissemination to multiple organ systems, including the skin. Vulvar nocardiosis is an exceedingly rare manifestation of Nocardia. Described is a patient with a history of lichen sclerosus, differentiated vulvar intraepithelial neoplasia (dVIN), and recurrent vulvar squamous cell carcinoma requiring multiple resections and biopsies who presented with recurrent firm, white, nodular lesions on the right labia and right inferior clitoris. Histopathology of the right inferior clitoral lesion demonstrated dVIN. The right labia majora lesion also revealed dVIN and a dermal epithelioid granuloma with central vacuoles filled with filamentous to small, fragmented forms suggestive of bacteria. Ziehl-Neelsen AFB stain was negative. Gram stain, Gomori methenamine silver (GMS), and FITE stains were positive. The staining pattern of the filamentous and beaded forms supports a diagnosis of Nocardia. Vulvar nocardiosis in the setting of dVIN and history of multiple vulvar surgeries has not been described in the literature to date. This case demonstrates the importance of maintaining atypical infections on the differential for nonhealing vulvar wounds. Timely treatment is crucial to improve outcomes, particularly in the setting of multiple surgical procedures in patients at high risk for infectious complications.

  PublisherDOI

Frequent coauthors

• Jorge Albores‐Saavedra

  Hospital Médica Sur

  164 shared

• Donald E. Henson

  Uniformed Services University of the Health Sciences

  164 shared

• Jian Wu

  Hebei Medical University

  163 shared

• Susan C. Abraham

  162 shared

• Volkan Adsay

  Koç University

  162 shared

• Semra Olgac

  Virginia Mason Medical Center

  162 shared

• Edi Levi

  John D. Dingell VA Medical Center

  162 shared

• Narasimhan P. Agaram

  Memorial Sloan Kettering Cancer Center

  162 shared

Labs

• Communications TeamPI