Keywords
pregnancy - adenocarcinoma - metastasis
Introduction
Adenocarcinoma is a neoplasm of epithelial tissue that has glandular origin. Adenocarcinoma
of the lung is prone to give metastases to the liver, spleen, and brain.[1] Brain metastasis is the most common intracranial tumor and has been observed in
10 to 40% of all cancer patients.[2]
Malignant tumors of the central nervous system (CNS) in pregnancy are rare and mostly
diagnosed in the second trimester of pregnancy.[3] Pregnant women presented with intracranial pathology rarely encountered in clinical
practice that requires neurosurgical intervention. Brain tumor during pregnancy occurs
very rare with an estimated incidence of 15 per 100,000.[4] Generally pregnancy is not considered to be a risk factor for developing a brain
tumor, and there is no evidence that shows higher prevalence of brain tumor in pregnant
women as compared with nonpregnant women of the same age group.[5] Physiologic changes during pregnancy, such as peritumoral edema as the result of
fluid shift mostly in the second and third trimesters, occur in immunologic and hormonal
status, and increased intra-abdominal pressure and hypercoagulability may have an
adverse impact on neurologic outcome and exacerbate tumor-related symptoms.[6]
We present a case of primigravida at 30 weeks of pregnancy diagnosed as metastatic
adenocarcinoma cerebrum, which radiologically mimics intracranial tuberculoma with
its primary focus on originating from the lungs.
Case Report
A 24-year-old-woman presented with history of two episodes of convulsions with 7½-month
amenorrhea. The convulsions were generalized tonic and clonic in nature. The patient
also had a history of headache, intermittent vomiting, and difficulty in speech from
last 7 days. There was right-sided progressive weakness noticed since last 2 days.
The patient had no history of any trauma or head injury in the recent past. She was
antenatally registered and had no major obstetric complaints. She had no significant
history. On examination she was conscious but drowsy. Her Glasgow coma scale (GCS)
was E3V4M6. Bilateral pupils were normal in size and normal reacting to light. Right-sided
hemiparesis with a motor power of 3/5 presented in both upper and lower limbs. On
preanesthetic assessment, the patient had a decreased air entry on left side of the
chest without clinically appreciable adventitious sounds. She was clinically afebrile,
and all other laboratory investigations including chest X-ray were within normal limits.
Other systemic examination did not revealed any abnormality. Magnetic resonance imaging
(MRI) of the brain showing a well-defined lobulated, centrally necrotic space-occupying
lesion (SOL) in the left posterior frontal suprasylvian region ([Fig. 1]). Magnetic resonance spectroscopy (MRS) reveals significant elevated lipid lactate
peaks with normal choline/creatine and choline/N-acetylaspartate (NAA) ratio. The overall imaging findings were suggestive of infective
pathology, most likely tuberculoma. After a multidisciplinary consultation with the
team involved, it was decided not to delay the surgery in view of rapid deterioration
in patient's neurologic state and correlating radiologic findings. Anesthetic management
was tailored for both pregnancy and an intracranial SOL. Fetal heart rate (FHR) was
monitored prior to surgery and throughout the procedure and periodically for 24 hours
postoperatively. An obstetrician was requested to remain as standby for FHR assessment
and for an urgent cesarean section if required in case of fetal distress. The patient
underwent a left frontoparietal craniotomy and gross total excision of tumor under
general anesthesia. Intraoperatively tumor was soft, friable, and minimally vascular
in nature. Subsequent obstetric and ultrasound checkups were normal. Histopathologic
examination of resected specimen revealed features of metastatic adenocarcinoma-cerebrum
([Fig. 2]). To look for primary cause, bronchial biopsy was done, which was suggestive of
invasive, well-differentiated adenocarcinoma grade I ([Fig. 3]). The patient was then advised for adjuvant chemoradiotherapy. The rest of her pregnancy
was uneventful. She subsequently delivered a full-term healthy baby through elective
cesarean under general anesthesia. Six-month follow-up after discharge was uneventful.
Fig. 1 Axial (A) and coronal (B) views of magnetic resonance image (MRI) of the brain demonstrating left posterior-frontal
tumor with central necrosis.
Fig. 2 H&E section showing cerebral tissue with tumor mass composed of mild to moderate
pleomorphic cells arranged in glandular pattern with intracellular mucin, tumor cell
invading brain parenchyma with glial reaction.
Fig. 3 H&E section showing lung tissue having features of invasive, well-differentiated
adenocarcinoma grade I.
Discussion
Tuberculoma accounts for 20 to 30% of all intracranial tumors in India.[7] Its presenting features are as in decreasing order: seizers (60–80%), headache and
vomiting (50–70%), and focal neurological deficits (33–68%). They are usually present
as solitary lesion, but 15 to 35% are multiple. They are mostly located in the frontal
and parietal lobes and involve corticomedullary junction and periventricular regions.
Vascular distribution of the lesion is more in middle cerebral artery (MCA) region.
The computed tomography (CT)/MRI diagnosis of tuberculoma is nonspecific, and they
have to be differentiated from other causes of SOLs such as metastasis, cysticercus
granuloma, toxoplasmosis, fungal granuloma, and glioma. Primary brain tumors are likely
to be mistaken for tuberculoma, which are more likely to calcify and produce a hyperdense
lesion demonstrable on plain CT scan.[8]
[9] MRI finding changes according to the stage of the lesion, that is, noncaseating
granulomas and caseating granulomatous lesions with a solid center, and caseation
in the center then usually liquefies. When tuberculoma presented with the elements
of both liquefactive and coagulative necrosis showing mixed intensity on T1WI and
T2WI with a rim of variable thickness, it mimics like a malignant tumor.[9] MRS of tuberculomas is characterized by a prominent decrease in NAA/Cr and slight
decrease in NAA/Cho. Lipid-lactate peaks are elevated in only 86% cases of tuberculomas.[10] A similar pattern may also be observed in patients with toxoplasmosis and primary
CNS lymphoma. CT/MRI of the brain is the usual initial investigation done when a intracranial
mass is suspected. However, the diagnosis may be complicated by ambiguous radiologic
findings; thus the tissue biopsy remains the gold standard.[11]
Brain tumors in pregnancy are very rare with an estimated incidence of 15 per 100,000
pregnancies.[4] Haas et al proposed that the rates of intracranial tumor for women of childbearing
age (15–44 years) was less than expected compared with that in the general population
with an observed to expected ratio of 0.38.[12] For brain metastasis, the most common primary sites include the lung (52.3%), followed
by breast (8.9%), renal (5.4%), rectum (5.2%), gastric (5.2%), and colon (4.1%).[13] According to different series, at initial presentation up to 63% of the patients
have multiple tumors, whereas 37 to 50% present with a single brain metastasis.[14]
[15] Brain metastasis usually occurs at the gray-white junction and in the watershed
areas of the brain at the same sites as cerebral emboli. The usual distribution is
∼80% cerebral hemisphere, 15% cerebellum, and 3% brainstem, similar to blood flow.[2] A robust understanding of metastatic pattern from primary tumor is of interest for
clinical use. Hess et al proposed that the single organ was the dominant source of
metastases in seven sites, axillary lymph node from the breast (97%), intestinal lymph
node from the colon (84%), thoracic lymph node from the lung (66%), brain from the
lung (64%), meditational lymph node from the lung (62%), supraclavicular lymph node
from the breast (51%), and adrenal gland from the lung (51%).[14]
Lung cancer is one of the leading causes of death in women and has overtaken breast
cancer. There are only a few cases in the literature describing the diagnosis of lung
cancer during the course of a pregnancy. A very few cases have been reported in the
literature; 77% were non–small cell carcinoma (NSCLC) and most of them were adenocarcinoma.
Mostly patients were diagnosed with advanced disease not amenable to cure and requiring
systemic treatment. The median diagnosis onset age reported is around 34 to 36 years,
with a median gestational age at diagnosis of 27 to 29 weeks. Although the clinical
profile of lung cancer is similar in pregnant and nonpregnant patients, a pregnant
woman is more likely to be diagnosed with more advanced or metastatic disease. NSCLC
in women is the most frequent lung cancer diagnosed and adenocarcinoma is the predominant
histologic subtype. Postpartum maternal median survival is very poor and most patients
die within 1 year after delivery.[16]
[17]
[18]
[19]
All risks and benefits associated with pregnancy, the different treatment modalities,
the natural history of the disease, and outcomes must be discussed with the patient
and their family members. Risk factors that have to be considered when deciding the
most appropriate management include the severity and rate of progression of symptoms,
gestational age and location and size of the tumor. Pharmacologic interventions include
as, corticosteroids to reduce intracranial edema and accelerate fetal lung maturity
and antiepileptics to control maternal seizures. Delivery should be preferably by
cesarean section under general anesthesia to reduce the risks of cerebral herniation
and placement of an epidural catheter.[20]
Anna et al suggested that neurosurgical procedures were performed during pregnancy
in 48% and 19%, respectively, in malignant and benign brain tumors. Adverse outcomes
were not significantly associated with neurosurgical procedure, although these patients
experienced significantly more cesarean deliveries, likely as part of a definitive
treatment plan.[5] Cohen-Gadol et al published an institutional series including 14 patients with intracranial
neoplasms, 9 of whom underwent a neurosurgical procedure while pregnant. No fetal
or maternal complications were directly related to these procedures, and all mothers
who underwent surgery at or near term subsequently delivered healthy infants.[21]
Conclusion
Though MRI features can be suggestive of infective pathology and it may be compelling
to start ATT empirically (esp. during pregnancy when there is a risk in intervention),
a tissue diagnosis is necessary as uncommon lesions like a metastasis can be present.
