Pathology Outlines Case of Week Flashcards
Cysticercosis by Taenia solium
Cysticercosis by Taenia solium
Cysticercosis by Taenia solium
Cysticercosis by Taenia solium
Cysticercosis by Taenia solium
Cysticercosis is a systemic infection caused by ingestion of larval cysts of the cestode Taenia solium (pork tapeworm). It is acquired by swallowing food, water or feces from contaminated T. solium eggs. The human is considered an intermediate host. When the eggs are ingested they release onchospheres that penetrate the gut epithelium and enter the bloodstream. These egg forms then embed themselves into various tissues throughout the body, encyst and differentiate into cysticerci (Siddeswari et al, Rubin’s Pathology: Clinicopathologic Foundations of Medicine 6th Edition, 2012, Centers for Disease Control and Prevention).
Clinically, cysticercosis symptoms change based on the site affected. In the brain it manifests as headaches, seizures and convulsions. In the heart it may cause arrhythmias. Cutaneous involvement is rare, but if present it presents as a palpable, subcutaneous nodule that may become painful if large enough (Siddeswari et al, Rubin’s Pathology: Clinicopathologic Foundations of Medicine 6th Edition, 2012).
In the present case, the gross specimen was composed of a cystic mass measuring 4 x 3 x 3 cm. The cut section showed a milky white to clear cyst with an envaginated scolex (head of tapeworm). Histology reveals a convoluted pattern of multilayered cysts composed of an outer cuticle layer, a middle nuclear layer and an inner parenchymal layer, diagnostic of cysticercosis. Birefringent hooklets can be present and a granulomatous reaction with mixed inflammatory infiltrate, fibrosis and calcification may also be appreciated.
The differential diagnosis includes other infestations. Taenia saginatum causes human taeniasis, but it causes cysticercosis in cattle. Echinococcus granulosis is a tapeworm that resides in the small bowel of dogs, sheep, goats and cattle. Humans are the intermediate hosts. They become infected by ingesting tapeworm eggs and this results in the development of hydatid cysts (Siddeswari et al, Rubin’s Pathology: Clinicopathologic Foundations of Medicine 6th Edition, 2012). Histologically, these cysts surround a thick fibrous capsule with an inner germinal layer which may contain a clear hydatid fluid. The cyst is most commonly found in the liver and may cause obstructive jaundice. Paragonium westermani is a lung fluke that causes paragonimiasis, a pulmonary infection caused by ingestion of undercooked crab. Histologically, the paragonium eggs are found in tissue sections and display a thick, highly retractile wall with operculum on either end of the eggs with adjacent non-necrotizing granulomas and organizing pneumonia (Burger, P. et al, Diagnostic Pathology: Neuropathology, 2nd edition, 2016).
Treatment for cysticercosis involves anti-helminthic therapy such as praziquantel and albendazole or surgery depending on the size and location of lesions (Am Fam Physician 2007;76:91).
Extensive prostatic intraductal carcinoma
Extensive prostatic intraductal carcinoma
A 58 year old man with hypertension presented with urinary frequency, urgency and nocturia. He had a hard prostate and a PSA of 1.9. He had a prostate biopsy (shown below), and then a radical prostatectomy with lymph node dissection
CK903
Extensive prostatic intraductal carcinoma
CK903
Extensive prostatic intraductal carcinoma
The biopsy showed intraductal carcinoma with foamy gland features in 5 cores in the left lobe, and intraductal carcinoma with foci suspicious for high grade invasive adenocarcinoma in the right lobe. In the prostatectomy specimen, there was 90% involvement of Gleason grade 5+5=10 invasive adenocarcinoma, but lymph nodes were negative. The tumor was staged as T2c N0 Mx.
Intraductal carcinoma of the prostate is an uncommon biopsy finding. It has been defined by Epstein et. al. as malignant epithelial cells filling large acini and prostatic ducts, with intact basal cells, in either: (1) solid or dense cribriform patterns or (2) loose cribriform or micropapillary patterns with either marked nuclear atypia (nuclear size 6 x normal or larger) or comedonecrosis (Mod Pathol 2006;19:1528). More than one pattern is usually present. The presence of basal cells can be confirmed by CK903 or p63 immunostains. Intraductal carcinoma of the prostate at biopsy is frequently associated with high grade, high volume adenocarcinoma and poor prognosis, suggesting that it represents an advanced stage of tumor progression with intraductal tumor spread, and not a precursor lesion (Am J Clin Pathol 2010;133:654, Arch Pathol Lab Med 2012;136:418).
The differential diagnosis includes high grade PIN, which is less often associated with invasive disease, and by itself, has a better prognosis (J Clin Pathol 2007;60:856). Important diagnostic criteria for intraductal carcinoma that may help distinguish it from HGPIN include marked nuclear pleomorphism, non-focal comedonecrosis (>1 duct showing comedonecrosis), markedly distended normal ducts/acini, mitotic figures, ERG nuclear staining and cytoplasmic loss of PTEN (Korean J Pathol 2013;47:307). Intraductal carcinoma should also be distinguished from invasive cribriform prostate cancer and urothelial carcinoma involving the prostate.
Primary signet ring adenocarcinoma of prostate
Primary signet ring adenocarcinoma of prostate
Primary signet ring adenocarcinoma of prostate
Primary signet ring adenocarcinoma of prostate
Primary signet ring adenocarcinoma of the prostate is rare. A Mayo Clinic review identified only 9 cases (0.03%) at their institution from 1970-2008; a PubMed review identified only 51 cases reported during 1970-2009 (Mayo Clin Proc 2010;85:1130). Histologically, the tumor is composed of 5-50% signet ring cells due to intracellular accumulation of mucin compressing the nucleus into a crescent shape. The cytoplasmic vacuoles often stain positively for mucin (mucicarmine-50%, PAS-60%, Alcian Blue-60%), but may also contain lipid. Tumors are typically PSA+ and PAP+, as well as keratin+ and P504S+. They are typically negative for CEA. Classic prostatic adenocarcinoma is also present.
The most important differential diagnosis is metastasis from a GI primary, which is much more common, and should be ruled out with a GI workup. GI primaries lack classic prostatic adenocarcinoma cells, and are typically CEA+, PSA- and PAP-. In cases with limited signet ring cells, the differential also includes artifactual changes in lymphocytes post-TURP and benign signet ring change. In both cases, there is no classic adenocarcinoma, and the suspect cells are negative for PSA, PAP and mucin (Am J Surg Pathol 1986;10:795, Am J Surg Pathol 2002;26:1066).
These tumors are very aggressive. Historically, up to 75% of cases presented with locally advanced or metastatic disease at diagnosis, although the figure may now be lower due to PSA testing. Treatment is similar to traditional adenocarcinoma - surgery, radiation therapy and hormonal therapy. A recent report showed a 5 year cancer-specific survival rate of 84%, with improved survival in more recent cases (Prostate Cancer 2011;2011:216169).
Prostatic adenocarcinoma (Gleason score 3+3 = 6);
Prostatic melanosis
Prostatic adenocarcinoma (Gleason score 3+3 = 6);
Prostatic melanosis
Prostatic adenocarcinoma (Gleason score 3+3 = 6);
Prostatic melanosis
Prostatic adenocarcinoma (Gleason score 3+3 = 6);
Prostatic melanosis
Prostatic adenocarcinoma (Gleason score 3+3 = 6);
Prostatic melanosis
Prostatic adenocarcinoma (Gleason score 3+3 = 6);
Prostatic melanosis
Prostatic melanosis is the finding of melanin within prostatic stromal melanocytes and glandular cells. The stromal melanocytes are believed to transfer melanin to the epithelial cells (Am J Clin Pathol 1988;90:530). Prostatic melanosis may be an isolated finding, associated with blue nevus (Eur Urol 1992;22:339) or associated with other prostatic pathology such as adenocarcinoma, as in this case.
The differential diagnosis includes lipofuscin pigment and blue nevus. Although lipofuscin is characteristic of ejaculatory ducts and seminal vesicles, it is also found in prostatic epithelium (Am J Surg Pathol 1994;18:446, Mod Pathol 1996;9:791). It is composed of golden yellow-brown to gray-grown granules (lipofuscin in hepatocytes). It stains with PAS-diastase, Congo Red, Luxol fast blue, Oil red O and Ziehl-Neelsen. Both lipofuscin and melanin stain with Fontana-Masson stain, but lipofuscin is S100 negative.
Blue nevus exhibits spindled stromal cells with marked melanin deposition (cellular blue nevus in skin). Nevus cells without pigment are usually present.
There is no clinical significance to the presence of melanosis in the prostate.
