A 15 year old male with a past medical history significant
for Tetralogy of Fallot (congenital heart defect), multiple valve replacements,
chronic kidney disease, and prior Bartonella endocarditis. He presented with a
“flu-like” illness including muscle aches, fevers, fatigue, and night sweats. His
symptoms slowly dissipated after about three days. However, he had labs drawn
including multiple blood culture sets which were all positive for growth.
Gram stain showed gram positive bacilli and culture plates grew two morphologies of slow growing gray, granular and opaque colonies.This organism was identified by MALDI-TOF as Corynebacterium pseudodiphtheriticum.
genus Corynebacterium comprises a
collection of irregular-formed, rod-shaped or coccoid bacteria that are
non-motile, catalase-positive, and non-spore-forming.
(previously designated as Corynebacterium
hofmannii) is a nonlipophilic, nonfermentive, urease- and nitrate-positive Corynebacterium species.1C. pseudodiphtheriticum is part of the
usual oropharyngeal bacterial flora, including the nares and throat. It appears
to play a role in preventing colonization of oropharyngeal epithelia by
commonly, C. pseduodiptheriticum is a
pathogen of the respiratory tract with cases of nosocomial and
community-acquired pneumonia, bronchitis, tracheitis, pharyngitis, and
rhinosinusitis. Endocarditis is the second most common infection site, although
very rare. Cases of urinary tract and wound infections have also been reported.
is usually with penicillin alone or in combination with aminoglycosides. Antibiotic
susceptibility profiling of C.
pseudodiphtheriticum isolates showed that resistance to oxacillin,
erythromycin, clindamycin, and macrolides are common.1
A sixty nine year old female who underwent right breast reconstruction about 13 years ago due to breast cancer presents to the doctor office with right breast pain and right breast enlargement over the last two months. She has lost some weight and does not recall any trauma to this area. She had a textured saline implant. Examination reveals no definite palpable masses. MRI of right breast showed intact saline implant with moderate amount of fluid surrounding the implant within the intact external capsule. No adenopathy was noted. Right breast implant was removed and complete capsulectomy was performed.
anaplastic large cell lymphoma.
Breast implant associated
anaplastic large cell lymphoma is a provisional entity that is morphologically
and immunophenotypically similar to ALK-negative anaplastic large cell lymphoma.
It arises primarily in association with a breast implant. It is a very rare
entity with an incidence of 1 in 500,000 to 3 million women with implants. Tumor
cells may be localized to the seroma cavity or may involve pericapsular fibrous
tissue. Sometimes it can form a mass lesion. Locoregional lymph node may be
involved. The mean patient age is 50 years. Most patient presents with
stage 1 disease, usually with peri-implant effusion. The mean interval from
implant placement to lymphoma diagnosis is 10.9 years. There is no association
with the type of implant. Histologic examination shows two different types of
proliferations. In patients with seroma, the proliferation is confined to the
fibrous capsule (“in situ” iALCL). However, the distribution of neoplastic
lymphocytes could be heterogeneous with some cellular areas with numerous large
pleomorphic cells of varying size and some fibrotic areas with rare atypical
lymphocytes. It is beneficial to look at the seroma fluid in addition to
capsule sections, because sometimes the neoplastic lymphocytes are
predominantly present in fluid (as in our case). Patients presenting with tumor
mass show more heterogeneous proliferations infiltrating surrounding tissues
(“infiltrative” iALCL). They consists of either sheets are clusters of large
neoplastic cells accompanied by a large number of eosinophils. By immunohistochemistry,
the tumor cells are strongly positive for CD30. CD2 and CD3 are more often
positive than CD5. CD43 is almost always expressed. Most cases are CD4 positive. The
prognosis is very good in patients with disease confined to the capsule.
The median overall survival is 12 years. However, patients with a tumor mass
could have a more aggressive clinical outcome.
1. Swerdlow SH, Campo E, Harris NL, et al. WHO Classification of Tumours of
Haematopoetic and Lymphoid Tissues (Revised 4th edition). IARC: Lyon
2. Jaffe, E , Arber, D, et al. Hematopathology (second edition) 2017.
-Junaid Baqai, MD, was born in Chicago, IL but spent most of his life in Karachi, Pakistan. He graduated from DOW Medical College in Pakistan and did his residency in anatomic and clinical pathology at Danbury Hospital, CT followed by hematopathology fellowship from William Beaumont Hospital, Michigan and oncologic-surgical pathology fellowship from Roswell Park Cancer Institute, New York. He currently serves as Medical Director of hematology, coagulation and flow cytometry at Memorial Medical Center and Medical Director of Laboratory at Taylorville Memorial Hospital.
A 24 year old male with no past medical history presented with
fevers, myalgia, and cough following return from a 1-week trip to Guatemala
where he spent significant time within caves. The patient described his cough
as persistent, non-productive, and associated with mild shortness of breath at
rest that significantly worsens with activity. In the emergency department, the
patient was afebrile with a WBC of 10.2, Transaminitis, and chest X-ray showed
diffuse reticular pattern. He underwent a bronchoscopy and BAL washout.
Histoplasmosis Urine Antigen test came back positive.
capsulatum is an intracellular, thermally dimorphic fungus (grows as a
yeast at body temperature/37°C in humans or culture media and as mold at 25°C
in the environment/culture media). Histoplasma
is found in soil, particularly in areas containing bird and bat droppings,
such as caves. Within the United States Histoplasma
in found in central and eastern states with a predominance in the Ohio and
Mississippi River Valleys. This fungus is also found in parts of Central and
South America, Africa, Asia, and Australia.
Histoplasma capsulatum causes
significant morbidity and mortality worldwide. Upon inhalation of conidia, H. capsulatum transforms into the
pathogenic yeast phase. This form replicates within macrophages that carry the
yeast from the lungs to other organs. Histoplasmosis has three main forms:
primary histoplasmosis which presents as a pneumonia with fever, cough,
cavitary histoplasmosis which is characterized by pulmonary lesions that often
resemble cavitary tuberculosis.
disseminated histoplamosis that spreads to infect many organs in
In the laboratory, culture of blood, tissue and respiratory
specimens may be completed. In addition, a test for H. capsulatum
antigen is sensitive and specific when simultaneous serum and urine specimens
are tested. It is important to note that cross-reactivity with other fungi (Coccidioides
immitis, Blastomyces dermatitidis, Paracoccidioides brasiliensis,
Penicillium marneffei) has been identified.
Growth on fungal culture shows white/tan, fluffy mold
that turns to brown to buff with age. The organism may also produce wrinkled,
moist, or heaped yeast-like colonies that are soft and cream when grown at 37°C
on certain media. Scotch tape preparation of the mold form shows tuberculate
macroconidia, a diagnostic structure of Histoplasma
capsulatum. The mycelia are septate and produce microconidia and
macroconidia. Yeast forms of Histoplasma
capsulatum are small (2 to 4 μm) and reproduce by budding. These budding
forms may be seen on histology specimens. A commercially available DNA probe
can be performed on culture material to confirm identification.
Patients with mild-moderate histoplasmosis can often have
resolution of their symptoms without treatment. Those with more moderate-severe
disease require antifungal agents including amphotericin B or itraconazole.
-Nicole Mendelson, MD
is a 1st year Anatomic and Clinical Pathology resident at the
University of Vermont Medical Center.
-Christi Wojewoda, MD, is the Director of Clinical Microbiology at the University of Vermont Medical Center and an Associate Professor at the University of Vermont.
76 year old man with a history of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) with new anterior mediastinal mass and increasing lymphadenopathy.
Lymph Node Biopsy
Tissue sections show a diffuse atypical lymphoid infiltrate
that completely effaces the normal nodal architecture. The infiltrate is
composed of numerous small lymphocytes with round to mildly irregular nuclei,
clumped chromatin, inconspicuous nucleoli and scant cytoplasm. There are also
expanded pale areas that contain intermediate sized cells with more open
chromatin and distinct single to multiple nucleoli. These cells are most
consistent with prolymphocytes/paraimmunoblasts and form the proliferation
centers characteristic of CLL/SLL. Occasional centroblastic-type B-cells are
noted within these proliferation centers. In addition, there are scattered single
to multinucleated cells that have irregular nuclear membranes with pale,
vesicular chromatin and prominent inclusion-like, eosinophilic nucleoli. These
cells morphologically resemble Hodgkin cells, Reed-Sternberg cells, mummified
forms and other variants. These large cells are more evident in areas with a
histiocyte rich background and around foci of necrosis. Occasionally, apoptotic
bodies and mitotic figures are seen.
show that the vast majority of the small-intermediate lymphocytes express B-cell
markers CD20 (dim) and PAX5 and co-express CD5 and CD23 (subset). This is
consistent with a background of CLL/SLL. The large atypical cells are positive
for CD30, PAX5 and CD20 (variable). CD3 highlights numerous scattered
background small T-cells, which are increased in the areas with the large cells.
In situ hybridization for Epstein Barr viral RNA (EBER ISH) is mainly staining
the large atypical cells. By Ki-67, the proliferation fraction is overall
increased (40%) with increased uptake by the large atypical cells.
The morphologic and immunophenotypic findings are consistent
with involvement by the patient’s known small lymphocytic lymphoma/chronic
lymphocytic leukemia (SLL/CLL) with aggressive morphological features. The
aggressive features include expanded proliferation centers and an elevated
Ki-67 proliferative index (40%). Additionally there are histiocyte/T-cell rich
areas composed of multiple EBV positive large atypical cells with morphologic
and immunophenotypic features compatible with Hodgkin/ Reed-Sternberg cells.
These areas are most in keeping with evolving classic Hodgkin lymphoma. Sheets
of large cells indicative of large cell transformation are not seen, although
increased scattered large centroblastic-type B cells are present.
Lymph node involvement by CLL/SLL will typically show a
diffuse proliferation of small lymphocytes with effacement of the normal nodal
architecture. The small lymphocytes have
round nuclei, clumped chromatin and scant cytoplasm. Scattered paler areas
known as proliferation centers are characteristic of this entity. The
proliferation centers are composed of a mixture of cell types including small
lymphocytes, prolymphocytes and paraimmunoblasts. Prolymphocytes are small to
medium in size with relatively clumped chromatin, whereas paraimmunoblasts are
larger cells with round to oval nuclei, dispersed chromatin, eosinophilic
nucleoli and slightly basophilic cytoplasm. Some cases show increased and
enlarged proliferation centers with a higher proliferation rate. This must be
distinguished from large cell transformation.1
Aggressive features of CLL/SLL include proliferation centers
that are broader than a 20x field or becoming confluent. An increased Ki-67
proliferation >40% or >2.4 mitoses in the proliferation centers can also
portend a more aggressive course. These cases tend to have worse outcomes than
typical CLL/SLL and better outcomes than cases that have undergone Richter
transformation to diffuse large B-cell lymphoma (DLBCL). Transformation to
DLBCL occurs in 2-8% of patients with CLL/SLL. Less than 1% of patients with
CLL/SLL develop classic Hodgkin lymphoma (CHL). In order to diagnose CHL in the
setting of CLL/SLL, classic Reed-Sternberg cells need to be found in a
background appropriate for CHL, which includes a mixed inflammatory background.
The majority of these CHL cases will be positive for EBV.1
Richter’s transformation is defined as an aggressive
evolution of CLL. While the most common type of transformation is to a
high-grade B-cell Non-Hodgkin lymphoma, other histological transformations have
been described. This includes CHL, lymphoblastic lymphoma, hairy cell leukemia
and high-grade T-cell lymphomas. The prognosis for patients who present with
transformation to CHL is poor compared to de novo CHL.2
A large study from the M.D. Anderson Cancer Center described 4121 patients with
CLL/SLL and found that only 18 patients or 0.4% developed CHL. The median time
from CLL to CHL diagnosis was 4.6 years. Fourteen of the patients received
chemotherapy. The overall response rate was 44% with a complete response rate
of 19%. The median overall survival was 0.8 years and all patients eventually
died from disease recurrence or progressive disease.3 This dismal
prognosis is similar to patients with Richter transformation to DLBCL and much
worse than patients with de novo CHL, which is curable in >85% of cases.1
Swerdlow SH, Campo E, Harris NL, et al. WHO
Classification of Tumours of Haematopoetic and Lymphoid Tissues (Revised 4th
edition). IARC: Lyon 2017.
Janjetovic S, Bernd HW, Bokemeyer C, Fiedler W. Hodgkin’s
lymphoma as a rare variant of Richter’s transformation in chronic lymphocytic
leukemia: A case report and review of the literature. Mol Clin Oncol.
Tsimberidou, AM, O’Brien, S and Kantarjian, HM,
et. al. Hodgkin transformation of chronic lymphocytic leukemia. Cancer. 2006;107(6).doi.org/10.1002/cncr.22121.
–Chelsea Marcus, MD is a Hematopathology Fellow at Beth Israel
Deaconess Medical Center in Boston, MA. She has a particular interest in
High-grade B-Cell lymphomas and the genetic alterations of these
A 30 year old
African American male presented to the emergency department (ED) with fevers
and cough. His past medical history was significant for type 1 diabetes & diabetic
nephropathy requiring a kidney/pancreas transplant
three years prior. He is compliant with his immunosuppressant regimen. He
described the cough as non-productive and denied shortness of breath or chest
pain. He denied sick contacts, recent travel, and has no pets. After hospital
admission, he became septic, developed severe hypotension (70/30s), and was transferred to the
intensive care unit (ICU). Chest x-ray showed multifocal consolidations in
bilateral lung fields and a small pleural effusion consistent with pneumonia. He was empirically started
on vancomycin, piperacillin-tazobactam, azithromycin, and micafungin.
Infectious diseases was consulted and recommended a board variety of tests and
cultures given the patient immunosuppressed status.
results were obtained:
culture: normal respiratory flora, negative for fungi and acid fast bacilli
viral PCR panel: positive for adenovirus, coronavirus, and rhinovirus
Given this positive serum result for Cryptococcus neoformans despite multiple negative sputum cultures, a bronchoalveolar lavage & lumbar puncture were performed and bacterial & fungal cultures were performed.
Cryptococcus neoformans is an encapsulated yeast that
is most commonly acquired through inhalation and can infect & disseminate
to multiple organ systems including the lungs, central nervous system, skin and
bones, especially in immunocompromised patients such as those with HIV or organ
transplant patients. The thick polysaccharide capsule gives colonies of C. neoformans a mucoid appearance, serves
as a major virulence factor, and also plays an important part in various
laboratory identification methods.
In the lab, C. neoformans will grow a variety of
selective and non-selective agars including blood, chocolate, Sabouraud dextrose,
and cornmeal agars as discrete, cream colored colonies (Image 2). On
microscopic examination, the C.
neoformans yeast are gram positive with narrow based budding and a thick
capsule. The yeast vary in size from 2-20 µm and are evenly spaced from one
another due to the capsule. C. neoformans
is positive for both urease and phenoloxidase. Historically, India ink stain
was performed on CSF specimens to highlight the capsule using direct
microscopy. Grocott’s methenamine silver (GMS), mucicarmine, and Fontana-Masson
histochemical stains are all positive for C.
antigen tests directed to the capsular polysaccharide can also be used to
diagnosis C. neoformans infections
from both serum and CSF specimens. Common methods include immunochromatographic
lateral flow assays or particle agglutination. Advantages to these methods
include increased sensitivity and the ability to provide semi-quantitative
titer results which can be used to monitor the patient’s response to therapy.
Rarely, false negative results can occur due to extremely high concentrations
of the cryptococcal antigen. In order to combat the prozone effect, the sample
should be diluted prior to repeating the test if there is a high suspicion of
cryptococcal infection. False positive results may also occur when macroglobulins
are present in the sample due to disease states such as rheumatoid arthritis or
lupus. Use of pronase can prevent the interference of macroglobulins on serum
test results. False positive test results have also be documented due to interferences
from various collection devices such as anaerobic vials.
In the case
of our patient, as C. neoformans is
intrinsically resistant to echinocandins, he was switched from micafungin to
fluconazole. He responded well and after completing the therapeutic course, he
continued on a prophylactic dose of fluconazole. His cerebrospinal fluid
culture showed no growth and the cryptococcal lateral flow assay was negative
on the CSF specimen.
-Charles Middleton, MD, is a first year Anatomic and Clinical
Pathology resident at the University of Mississippi Medical Center.
-Lisa Stempak, MD, is an Assistant Professor of Pathology at the
University of Mississippi Medical Center in Jackson, MS. She is
certified by the American Board of Pathology in Anatomic and Clinical
Pathology as well as Medical Microbiology. She is the Director of
Clinical Pathology as well as the Microbiology and Serology
Laboratories. Her interests include infectious disease histology,
process and quality improvement, and resident education.
A 69 year old male with complicated past medical history of
sarcoidosis, pulmonary nodules, atrial flutter, right septic arthritis,
pulmonary embolism and coronary artery disease presented to the emergency
department with worsening cardiac symptoms for the past few days. He denied any
symptoms of fever, cough, dyspnea, or palpitations. He has no history of TB
exposure, high-risk occupation or volunteer work. Chest x-ray, echocardiogram and computerized tomography (CT) scan
were performed and he was diagnosed with constrictive pericarditis. Pericardiotomy
was performed which showed thickened and calcified pericardium. On pericardial
biopsy specimen, acute necrotizing and granulomatous pericarditis was
identified (Image 1). Acid fast bacteria stain for mycobacteria was performed which
showed numerous acid-fast bacilli (Image 2). In house validated testing for M. tuberculosis by PCR amplification of the IS6110
insertion sequence and nontuberculous mycobacteria species determination by
heat shock protein 65 (hsp65) gene
with melt curve analysis was performed. Testing was negative for M. tuberculosis. Nontuberculous
mycobacteria testing was consistent with M.
xenopi. For definitive diagnosis, culture was performed which grew M. xenopi (Image 3).
M. Xenopi is a
free-living nontuberculous mycobacterium (NTM). NTM are present in
the environment, mainly in water, and are occasionally responsible for opportunistic
infections in humans.1
With the availability of 16S
ribosomal DNA sequencing and high-performance liquid chromatography (HPLC),
polymerase chain reaction-restriction length polymorphism analysis (PRA), and
multi-gene and whole-genome sequencing, the number of new species of
nontuberculous mycobacteria has risen dramatically. There are
about 180 different species of mycobacteria. The most common nontuberculous species causing
human disease in the United States are the slowly growing species, Mycobacterium avium complex and M.
kansasii. Less common human pathogens include the slowly growing
species M. marinum, M. xenopi, M. simiae, M.
malmoense, and M. ulcerans, and the rapidly growing
species M. abscessus complex, M.
fortuitum, and M. chelonae.2 NTM can
cause pulmonary disease, osteomyelitis or disseminated disease in
Microscopic examination after acid fast or fluorescent
Auramine-Rhodamine staining and AFB culture using LJ and Middlebrook 7H10 media
are the cornerstones of the identification of mycobacteria. All mycobacteria
share the characteristic of “acid-fastness,” ie, after staining with
carbol-fuchsin or auramine-rhodamine, they do not decolorize with acidified
alcohol. Confirmation of the presence or absence of mycobacteria in clinical
specimens requires culture, because of the relative insensitivity of direct
The presented case highlights the importance of NTM causing
infection in pericardium which is very rare. Special stains, molecular testing,
and culture can aid in timely identification of the organism and aid in patient
Tortoli E. Microbiological
features and clinical relevance of new species of the genus Mycobacterium.
Clin Microbiol Rev 2014; 27:727.
Griffith DE, Epidemiology of nontuberculous mycobacterial
infections. Reyn CF UpToDate. April 2017.
Griffith DE, Microbiology of nontuberculous mycobacteria.
Reyn CF UpToDate. Sept 2018.
Kaur, MD MBBS is a 2nd year anatomic and clinical pathology resident at University
of Chicago (NorthShore). Academically, Amandeep has a particular interest in
-Erin McElvania, PhD, D(ABMM), is the Director of Clinical
Microbiology NorthShore University Health System in Evanston, Illinois.
Follow Dr. McElvania on twitter @E-McElvania.
The patient is a 72 year old female who overall has been
fairly healthy. She has struggled with a cough for several years. A CT scan in
2015 showed some tree-in-bud changes in the lungs potentially consistent with
an atypical mycobacterial infection. She had a positive methacholine challenge
test and was diagnosed with asthma. Her cough has not improved with inhaled
asthma treatments. The cough has been persistent and is at times productive of
small amounts of whitish sputum. She has not noted any progressive shortness of
breath. Over the last several months she has tried trials of both nasal
corticosteroids, and treatment with Prilosec for gastroesophageal reflux. Both
of these trials had no effect on her cough. At the end of November 2018, a CT
scan of the chest was consistent with an atypical mycobacterial infection.
In January 2019, she came back from a skiing trip. She tried
to ski but was unable to because of shortness of breath; she came home on the third
day prematurely. During this time, she developed increased cough, fevers and
chills. An x-ray was obtained by her primary care provider, which showed a
right lower lobe infiltrate, and was placed on levofloxacin for 5 days. After
completing the antibiotic, she is still very fatigued and still coughing. She
presented to her pulmonologist in March 2019. She denied any fevers, chills or
chest pain. Her cough has continued with intermittent sputum production. Her appetite
and weight have been stable, along with bladder and bowel habits.
The patient’s past medical history is significant for arthritis, cataracts, depression, polymyalgia rheumatica, and sciatic nerve pain. Her past surgical history is only a tonseillectomy in her childhood. Her social and family history is that she runs an educational travel business, is currently divorced, has never been a smoker, and has no family history significant for recurrent infections.
Induced sputum samples were obtained and inoculated on a
7H9 bottle that was incubated and continuously monitored for growth. Eight days
later, the 7H9 bottle flagged positive for growth. A gram stain showed
branching gram positive bacilli. The Kinyoun acid-fast stain was negative, but
a modified Kinyoun showed rare positive staining cells. The bottle was
subcultured onto chocolate agar, 7H11 agar, buffered charcoal yeast extract
(BCYE) agar, and LJ slants. Two days later, all plates except the 7H11 plate
showed growth of white, dry, crinkled colonies as depicted in Image 1. A gram
stain of the colonies showed branching gram positive bacilli as shown in Image
2. Again, the Kinyoun stain of the colonies was negative but the modified
Kinyoun again highlighted cells as seen in Image 3. A representative colony was
sent for identification to Mayo laboratories a day later. MALDI-TOF performed by Mayo Laboratories
revealed the bacteria to be Rothia aeria.
An attempt was made to set up sensitivities but the organism was not able to
grow out on the test medium.
is a very rare pathogen with a current PubMed search yielding 20 references. It
was first isolated from the MIR space station (1) and genomic sequencing was
perform on the bacteria (2). It has been shown to be a normal oral flora (3),
but also seems to be most associated with endocarditis. A few case reports have
discussed sepsis, respiratory infections, and joint infections. Importantly, it
has been documented to be confused with Nocardia species (4).
Li, Y. et al. Rothia aeria sp. nov., Rhodococcus
baikonurensis sp. nov., and Arthrobacter russicus sp. nov., isolated from air
in the Russian space laboratory Mir. Int J Syst Evol Microbiol. 2004; 54(pt.
Nambu, T. et al. Complete Genome Sequence of
Rothia aeria Type strain JCM 11412, Isolated from Air in the Russian Space
Laboratory Mir. Genome Announc. 2016 Dec 29; 4(6).
von Graevenitz, A. et al. Coryneform bacteria in
throat cultures of healthy individuals. J Clin Microbiol. 1998; 36: 2087-2088.
Saraya, T. et al. Rothia aeria: a great mimicker
of the Nocardia species. BMJ Case Rep. Published Online: November 18, 2014.
-Jeff Covington, MD, PhD is a 2nd
year anatomic and clinical pathology resident at the University of Vermont
-Christi Wojewoda, MD, is the Director of Clinical Microbiology
at the University of Vermont Medical Center and an Associate Professor
at the University of Vermont.